submarine geology and geophysics

OLR(1984)31 (11) 783

be addressed separately. Coatings are generally used to protect above water structures; cathodic protection is the primary tool to combat subsea corrosion.

Types of coatings and their applications and the advantages and limitations of two types of cathodic protection are discussed. (bwt)

D. SUBMARINE GEOLOGY AND GEOPHYSICS

D10. Apparatus and methods

84:5492 Barrodale, I., N.R. Chapman and C.A. Zala, 1984.

Estimation of bubble pulse wavelets for deconvolution of marine seismograms. Geophys. Jl R. astr. Soc., 77(2):331-341.

A method for estimating bubble pulse wavelets directly from marine seismograms is described and illustrated with a least absolute value deconvolution algorithm. The method builds wavelet estimates in 3 stages; the first 2 use information derived from individual seismograms. The usual minimum phase assumption is not employed in the method as direct measurements of source wavelets demonstrate that this assumption can be inappropriate in practice. Dept. of Computer Sci., Univ. of Victoria, P.O. Box 1700, Victoria BC, V8W 2Y2, Canada.

84:5493 Berkson, J.M. and J.E. Matthews, 1984. Statistical

characterization of seafloor roughness. (Invited paper.) IEEE Jl ocean. Engng, OE-9(1):48-52.

This paper presents a method of quantifying seafloor topography for the case of intermediate scale features which act primarily as sloping bottoms and small scale features which act as scatterers. 'Spatial wavenumber spectra of ocean bottom and subbottom roughness are determined from narrow- beamwidth echosounding and seismic reflection profiling.' The situation is more complicated than commonly assumed. The authors suggest a format for a proposed future seafloor roughness database. SACLANT, ASW Centre, La Spezia, Italy. (amt)

84:5494 Carter, J.A., F.K. Duennebier and D.M. Hussong,

1984. A comparison between a downhole seismometer and a seismometer on the ocean floor. Bull. seism. Soc. Am., 74(2):763-772.

Absolute noise levels and signal-to-noise ratios recorded by a downhole seismometer and a nearby (within 200 m) OBS in the deep ocean (5.5 km) are remarkably similar. This unexpected similarity is attributed to the shallow emplacement depth of the dowrthole instrument (194 m subbottom) and the soft sediment into which it was clamped. Rondout Associates, Inc., P.O. Box 224, Stone Ridge, NY 12484, USA.

84:5495 Dragoset, W.H. and K.L. Larner, 1984. Data

enhancement from a 500-channel streamer. (In- vited paper.) IEEE Jl ocean. Engng, OE-9(1):40- 47. Western Geophys. Co., P.O. Box 2469, Houston, Tex. 77252, USA.

84:5496 Edwards, R.N., D.C. Nobes and E. G6mez-Trevifio,

1984. Offshore electrical exploration of sedimentary basins: the effects of anisotropy in horizontally isotropic, layered media. Geophysics, 49(5):566-576. Dept. of Phys., Univ. of Toronto, Ont. M5S 1A7, Canada.

84:5497 Morgera, S.D. and Ravi Sankar, 1984. Digital signal

processing for precision wide-swath buthymetry. (Invited paper.) IEEE Jl ocean. Engng, OE- 9(2):73-84. Concordia Univ., Dept. of Elect. Engng., H-915, 1455 de Maisonneuve Blvd. W., Montreal, Que. H3G 1M8, Canada.

84:5498 Sejrup, H.P., Ktre Rokoengen and G.H. Miller,

1984. Isoleueine epimerization in Quaternary benthonic Foraminifera from the Norwegian continental sbeff: a pilot study. Mar. Geol., 56(1/4)'227-239.

Monospecific assemblages of known absolute ages were studied to 'evaluate the potential of...[isoleucine

784 D. Submarine Geology and Geophysics OLR (1984) 31 ( 11 )

epimerization] as a geochronological tool.' Relative ages of sedimentary units with 'in-situ faunas and similar thermal histories' can be gauged by isoleucine epimerization ratios in benthonic Foraminifera. When calibration sites are available, absolute ages may be approximated as well. Geol. Inst., Dept. B, Univ. of Bergen, Allegatn 41, 5000 Bergen, Norway. (mjj)

84:5499 Tatham, R.H. and D.V. Goolsbee, 1984. Separation

of S-wave and P-wave reflections offshore western Florida. Geophysics, 49(5):493-508. Geosource Inc., 6909 SW Freeway, P.O. Box 36306, Hous- ton, Tex. 77236-6306, USA.

84:5500 Thomson, D.J., 1984. An inverse method for recon-

structing the density and sound speed profiles of a layered ocean bottom. IEEE Jl ocean. Engng, OE-9(1): 18-25.

A method of inverting aperture- and band-limited seismic reflection data to obtain the velocity and density of sediments is discussed. The method requires 'data in the form of two impulse responses for two distinct grazing angles,' and is based on the scattering of plane waves by a 1-D inhomogeneous medium. The method was successfully tested using hand-limited synthetic data calculated for a geo- acoustic model of deep-sea sediments in the Hatteras Abyssal Plain. NUSC, New London Lab., New London, Conn. 06320, USA. (amt)

84:5501 Wang, Ren, 1983. A short note on the inversion of

tectonic stress fields. Tectonophysics, 100(1/3): 405-411.

Works on global and regional stress fields are briefly reviewed. Questions encountered in computing tectonic stress fields include: the earth model, driving forces, distinguishing criteria and residual stress. For the linear elastic case, a scheme using the superposition principle and the least squares method is described in terms of inverting the stress field of Eastern Asia under the action of the Indian, Pacific and Philippine plates. For the nonlinear case and the residual stress field the use of a trial and error scheme utilizing the historical tectonic movements is briefly described. Dept. of Geol., Peking Univ., Beijing, People's Republic of China.

D40. Area studies, surveys, bathymetry 84:5502

Bartole, Roberto, Daniele Savelli, Mario Tramon- tana and F.-C. Wezel, 1984. Structural and

sedimentary features in the Tyrrhenian margin off Campania, southern Italy. Mar. Geol., 55(3/4): 163-180.

E-W trending Miocene orogenic features comprise carbonate and allochthonous sheets thrust N-NE during Miocene tectonic activity; emplacement is attributed to gravitational gliding tectonics. Apen- nine (NW-SE) and anti-Apennine (NE-SW) trends in the Campanian margin reflect post-orogenic Plio-Quaternary extension. The latter trend is responsible for the remarkable block-faulting differential subsidence and present morphology of the southern margin. Includes fold-out lithofacies maps and sections. Ist. di Geol. dell'Univ, di Urbino, 1-61029 Urbino, Italy.

84:5503 Belderson, R.H., E.J.W. Jones, M.A. Gorini and

N.H. Kenyon, 1984. A long--range side-scan sonar (Gloria) survey of the Romanche active transform in the equatorial Atlantic. Mar. Geol., 56(1/4):65-78.

A narrow lineament which may be the active trace of the Romanche transform fault was traced almost continuously in 720 km of long-range side-scan sonar data in the Romanche Fracture Zone. Tec- tonic trends in the floor of the Romanche Trough and north and south of the trough were also mapped. The pole of rotation derived from the active fault trace does not describe either North America-Africa or Africa-South America motion, suggesting that transform motions near the Equator are not simply coupled to the movement of the bordering continental blocks. Inst. of Oceanogr. Sci., Wormley, Godalming, Surrey, UK. (amt)

84:5504 Carlson, P.R. and H.A. Karl, 1984. Discovery of two

new large submarine canyons in the Bering Sea. Mar. Geol., 56(1/4):159-179.

Two newly discovered canyons, St. Matthew and Middle, are smaller and not cut back into the Bering shelf like the five very large canyons, but are comparable in size to most of the canyons that have been cut into the U.S. eastern continental margin. Both igneous and sedimentary rocks of Eocene to Pliocene age have been dredged from the walls of St. Matthew and Middle Canyons, suggesting a late Tertiary to Quaternary genesis. The ancestral Yukon and possibly Anadyr rivers may have initiated the canyon-cutting processes. USGS, Menlo Park, Calif. 94025, USA.

OLR (1984) 31 (11) D. Submarine Geology and Geophysics 785

84:5505 Eittreim, S.L., D.Z. Piper, Henry Chezar, D.R. Jones

and Ansis Kaneps, 1984. Observations on Cre- taceous abyssal hills in the northeast Pacific. Mar. Geol., 56(1/4):41-64.

An abyssal hills area of 50 × 60 km was studied using bottom transponder navigation and long- traverse oblique photography. The block-faulted north-south hills are bounded by steep scarps; sedimentation is inhibited and pillow basalts often crop out. An ash layer at about 7 m subbottom blankets the area. This ash occurs in multiple beds altered to phillipsite and is highly consolidated; a 24 m.y. age is based on ichthyolith dates. Acoustically transparent Neogene sediments above the ash are thickest in trough bottoms and are composed of pale-brown pelagic clays of illite, quartz, smectite, chlorite and kaolinite. Dark-brown pelagic clays, rich in smectite and amorphous iron oxides, underlie the Neogene surficial sediments. Manganese nodules are most abundant near basement outcrops and where the subbottom ash layer is absent. USGS, Menlo Park, Calif. 94025, USA.

84:5506 Faug6res, J.-C., Eliane Gonthier and D.A.V. Stow,

1984. Contourite drift molded by deep Medi- terranean outflow. Geology, geol. Soc. Am., 12(5):296-300.

Seismic profiling, bottom photography, and closely spaced piston and gravity coring over the 50-km long, 300-m thick Faro Drift west of Gibraltar provide detailed data on the sandy, silty, and muddy contourite facies left by hydrodynamic fluctuations of deep Mediterranean outflow waters. Turbidites and hemipelagites are compared on the basis of structure, contact, bioturbation, grain size and grain-size distribution, composition, and vertical succession of facies and grading. The results should aid in the recognition of ancient contourites and serve to relate Late Quaternary climate changes to outflow variability. Dept. de Geol. et d'Oceanogr., Univ. de Bordeaux 1, Bordeaux, France. (hbf)

only where a sufficiently thick overburden accu- mulated over a well-developed mobile substrate. Then gravitational instability led to basinward sliding of the margin sediments over the Messinian series, which acted as a lubricant and a level of decollement. The mobility of this series is probably caused by overpressured shale beds confined between the impervious evaporites; this mechanism explains all the features of the slumps. Includes fold-out cross-sections and profiles. Dept. of Geol., Hebrew Univ., Jerusalem 91904, Israel.

84:5508 Mascle, J., C. Auroux and S. Rossi, 1984. Superficial

geological structure and recent evolution of the Apulian Swell (Ionian Sea). Revue Inst. f t . P~trole, 39(2):127-142. (In French, English abstract.) Lab. de Geodynam. Sous-Mar., BP 48, 06230 Villefranche sur Mer, France.

DSO. Subsurface structure

84:5509 Pautot, Guy, Chantal Le Cann, Alain Coutelle and

Yossi .Mart, 1984. Morphology and extension of the evaporitic structures of the Liguro-Provencal Basin: new Sea-Beam data. Mar. Geol., 55(3/4): 387-409.

Studies were undertaken to determine the distribution and morphology of the salt domes in this region; data were analyzed with respect to the influences of the sedimentary overload and of regional tectonic activities on halokinesis. The sediment cover in the delta regions of the RhOne and Var Rivers has a negative influence on halokinesis; no piercement structures can be seen. Deep-level tectonic activity and faulting have a primary role in halokinesis observed in the studied zones. Observed diapiric features are characteristic of the underlying layer. Dept. de Geol., Centre Oceanol. de Bretagne, F-29273 Brest, France.

84:5507 Garfunkel, Z., 1984. Large-scale submarine rots-

tional s imps and growth faults in the eastern Mediterranean. Mar. Geol, 55(3/4):305-324.

Submarine slumps of Plio-Quaternary silty-clayey sediments, up to 1.5-2 km thick, are broken by shore-parallel growth faults that flatten downward and become rooted in ridges formed by deformation of the underlying mobile Messinian evaporites. Deformation is thin-skinned; slumping occurred

84:5510 Recq, Maurice, Philippe Charvis and Alfred Him,

1983. Preliminary results on the deep structure of the Kerguelen Ridge, from seismic refraction experiments. C. r. Acad. Sci~ Paris, (1I)297(13): 903-908. (In French, English abstract.)

Initial results suggest an oceanic origin for the Kerguelen Islands and surrounding plateau; seismic velocity vs. depth distribution resembles those of aseismic oceanic ridges. Crustal depth at the eastern

786 D. Submarine Geology and Geophys ics OI .R 11984) 31 ( I [ i

end is only 15 km, thickening toward the archipelago center. Dept. de Geol. dynam., Univ. P. et-M. Curie, 4, place Jussieu, 75230 Paris Cedex 05, France. (sir)

D60. Geomorphology (fans, canyons, etc.)

84:5511 Amos, C.L. and E.L. King, 1984. Bedforms of the

Canadian eastern seaboard: a comparison with global occurrences. Mar. Geol., 57(1/4): 167-208.

Terminology applicable to bedforms is reviewed and related, where possible, to diagnostic generic characteristics identifiable in acoustic and seismic records of the southeastern Canadian shelf, where bedforms similar in type to those off the U.S. are recognizable. In particular, sand waves and sand ridges, their dimensions and significance, are discussed in some detail. Geol. Surv. of Canada, P.O. Box 1006, Dartmouth, NS B2Y 4A2, Canada. (hbf)

84:5512 Belderson, R.H., N.H. Kenyon, A.H. Stride and

C.D. Pelton, 1984. A 'braided' distriimtary system on the Orinoco Deep-Sea Fan. Mar. Geol., 56(1/4): 195-206.

Long range side-scan sonar, echo sounder and core data provide detail on the sediments and morphology of the portion of the fan abutting the Barbados Outer Ridge, a pre-orogenic setting where sediments appear destined to be incorporated into the ridge complex. Sinuous channels, 65 m deep and 3 km wide, branch downslope into a shallow braided-stream type pattern, then converge again to form a single channel to overtop a buried basement ridge. The evidence also suggests the presence of debris flows aligning some 'braided' channels. Stride: 123 Sussex Rd., Petersfield, Hants, UK. (hbf)

84:5513 Bellaiche, Gilbert et al., 1984. Detailed morphology,

structure and main growth pattern of the Rh6ne deep-sea fan. Mar. Geol., 55(3/4):181-193.

A sea-beam survey of the fan and its vector canyon shows unexpected striking similarities with continental landforms encountered in alluvial plain areas or desert countries. Fan structure as shown by continuous seismic profiles results from the stacking up of numerous lenticular acoustic units. Building of the fan began as early as the lower Pliocene with a growth pattern tightly associated with climatic fluctuations. Includes a fold-out bathymetry map. Lab. de Geodynam. Sous-Mar., Univ. P. et M. Curie, 06230 ViUefranche-sur-Mer, France.

84:5514 Elverhoi, Anders, 1984. Glacigenic and associated

marine sediments in the Weddell Sea, fjords of Spitsbergen and the Barents Sea: a review. Mar. Geol., 57(1/4):53-88.

Sediment composition, distribution and thickness, processes of deposition, and rates and factors controlling accumulation are reviewed for 3 environments: the Weddell Sea shelf, located outside a shelf periodically covered by grounded ice; the fjords of western and northern Spitsbergen, situated outside tidewater glaciers originating on a partially glaciated hinterland; and the Barents Sea, an epicontinental sea formerly covered by Late Weich- selian(?) grounded ice. Norwegian Polar Res. Inst., Box 158, 1330 Oslo Lufthavn, Norway. (hbf)

84:5515 Kastens, K.A. and F.N. Spiess, 1984. Dissolution and

collapse features on the eastern Mediterranean Ridge. Mar. Geol., 56(1/4):181-193.

Morphologic features similar to subaerial karstic dolines and zanj6nes were observed on the eastern Mediterranean Ridge; these features are found only on the floors of certain large depressions which lie above the crests of subcropping evaporite diapirs. The coincidence of dissolution-controlled morphology with the subcropping soluble evaporite confirms earlier suggestions that the large depressions result from evaporite dissolution and collapse of the overlying strata. Lamont-Doherty Geol. Observ., Palisades, NY 10964, USA.

84:5516 Mackiewicz, N.E., R.D. Powell, P.R. Carlson and

B.F. Molnia, 1984. Interlaminated iee-groximal glaeimarine sediments in Muir Inlet, Alaska. Mar. Geol., 57(1/4): 113-147. Northern Illinois Univ., DeKalb, Ill. 60115, USA.

84:5517 Powell, R.D., 1984. Glacimarine processes and

inductive lltho|acies modelling of ice shelf and tidewater glacier sediments based on Quaternary examples. Mar. Geol., 57(!/4): 1-52.

Possible facies relationships are considered for sedimentation models of 8 postulated glacimarine regimes based upon present and Pleistocene glacimarine sequences derived from a variety of glacial debris sources. The characteristics and depositional environments of ice-proximal sediments, ice shelf and tidewater iceberg zone sediments, and deeper- water zone sediments are described. (It is noted that the proper etymological connection between Latin roots is the letter i; hence, the term glacimarine is

OLR (1984) 31 (I 1) D. Submarine Geology and Geophysics 787

used here for 'sediment deposited in the sea after being released from grounded or floating glacial or sea ice.') Includes extensive bibliography. Dept. of Geol., Northern Illinois Univ., Dekalb, Ill. 60115, USA. (hbf)

D70. Coasts, beaches, marshes

84:5518 Baumann, R.H., J.W. Day Jr. and C.A. Miller, 1984.

Mississippi deltaic wetland survival: sedimentation versus coastal submergence. Science, 224(4653): 1093-1095.

Sedimentation processes and the consequent pro- gradation/deterioration of the marsh surface are contrasted in Barataria Bay, an interdistributary basin between an abandoned Mississippi River course and the river, and Fourleague Bay, an estuary of an active Mississippi distributary, the Atchafalaya River. Although Barataria Bay accretion, largely the product of hurricanes and tropical and winter storms, exceeds that of Fourleague Bay, where annual river floods are the dominant sediment source, a net loss of intertidal elevation due to storm erosion, subsidence, and sea level rise will eventually result in the conversion of the Barataria Bay marshes to open water areas. Center for Energy Stud., Louisiana State Univ., Baton Rouge, La. 70803, USA. (hbf)

84:5519 Dionne, J.-C., 1984. An estimate of ice--drifted

sediments based on the mud content of the ice cover at Montmagny, Middle St. Lawrence Estuary. Mar. Geol., 57(1/4):149-166.

Ice processes appear to dominate the sedimentary budget of the turbidity zone of the study area, 70 km northeast of Quebec City. It is estimated that of the total annual load of ice-borne fines (as much as 4 × 106 tons), ~15% returns to the tidal flat, 1.5-2 × 106 t enter the turbidity zone, and the balance becomes part of the 10 × 106 t ice-drifted offshore. Dept. of Geogr., Univ. Laval, Quebec G1K 7P4, Canada. (hbf)

84:5520 Orford, J.D. and R.W.G. Carter, 1984. Mechanisms

to account for the longshore spacing of overwash throats on a coarse dastic barrier in southeast Ireland. Mar. Geol., 56(1/4):207-226. Dept. of Geogr., The Queen's Univ. of Belfast, Belfast BT7 1NN, Northern Ireland.

84:5521 Thorn, B.G., 1984. Transgressive and regressive

strattgraphies of coastal sand barriers in southeast Australia. Mar. Geol, 56(1/4):137-158. Dept. of Geogr., Univ. of New South Wales, Duntroon, A.C.T. 2600, Australia.

84:5522 Wright, L.D. and A.D. Short, 1984. Morphodynamlc

variability of surf zones and beaches: a synthesis. Mar. Geol., 56(1/4):93-118.

Conclusions from field studies of Australian beach and surf zone morphodynamics are summarized. It has been shown that the beach state (reflective, dissipative, or some intermediate thereof) can influence hydrodynamic processes, sediment transport, and morphology. An empirical-statistical assessment of beach conditions relates environmental conditions to breaker height divided by the product of mean sediment fall velocity and wave period. Virginia Inst. of Mar. Sci., Gloucester Point, Va. 23062, USA. (hbf)

D80. Reefs and atolls

84:5523 Thomassin, B.A., 1984. Coral reefs in the western

Indo-Pacific: main types and successive stages of construction. Oceanis, 10(1):1-49. (In French, English abstract.)

Factors affecting the building of coral reefs are: continental or insular topography, sea level fluctuations during the Quaternary, changes in dominant winds and local tectonics, and biotic and abiotic factors connected with building species. The main evolutionary stages of bow reefs forming barrier lagoonal reefs are described. Includes many aerial photos and a 7 page bibliography. Sta. mar. d'Endoume, Centre d'Oceanol, de Marseille rue Batterie-des-Lions, 13007 Marseille, France.

84:5524 Trichet, J., P. Repellin and P. Oustrirre, 1984.

Stratigraphy and subsidence of the Mururoa Atoll (French Polynesia). Mar. Geol., 56(1/4):241-257.

Mineralogical, petrological, and geochemical studies previously published in French and unpublished thesis data on 3 deep boreholes which penetrated the carbonate caprock on the rim of Mururoa Atoll are reviewed. The results indicate the importance of diagenetic processes to the vertical mineralogical zonation of the reef and suggest that dolomitization may occur at the freshwater-lower marine water interface. Discontinuities in coral ages coincide with

788 D. Submarine Geology and Geophysics OLR (1984) 31 ( I I )

glacial falls of sea level. Since 7.2 myBP it is estimated that the underlying submerged volcano has subsided at a mean rate of 8 m/100,000 yr. Oustriere: Bur. de Rech. Geol. et Mar., BP 6009, F-45060 Orleans-Cedex, France. (hbf)

D110. Erosion

84:5525 Robb, J.M., 1984. Spring sapping on the lower

continental slope, offshore New Jersey. Geology, geol. Soc. Am., 12(5):278-282.

Echo-sounding and seismic reflection profiles, sidescan sonar mosaics, 84 sediment cores and 4 dives of DSRV Alvin on the continental slope and rise between Lindenkohl and South Toms canyons, New Jersey, suggest that the vertical and near- vertical walled basins may have been shaped during times of lowered sea level by the action of grain- by-grain spring sapping at the base of Tertiary outcrops. There is also evidence that various karst- like features may have resulted from solution of calcareous rocks by discharging fresh groundwater during those same periods of lowered seas. Includes bottom photos. USGS, Woods Hole, Mass. 02543, USA. (hbf)

D120. Sedimentary processes (deposition, diagenesis, etc.)

84:5526 Barrie, J.V., C.F.M. Lewis, G.B. Fader and L.H.

King, 1984. Seabed processes on the northeastern Grand Bank~ of Newfoundland; modern rework- ing of relict sedhmnts. Mar. Geol., 57(1/4):209- 227. Centre for Cold Ocean Res. Engng., Memorial Univ. of Newfoundland, St. John's, Nfld. A IB 3X5, Canada.

84:5527 Hollister, C.D. and I.N. McCave, 1984. Sedimen-

tation under deep-sea storms. Nature, Lond., 309(5965):220-225.

Fast currents, high concentrations of suspended sediment and grooved mud beds are associated with erosion in frequent abyssal storms where a fast deep mean flow is augmented (or reversed) by intense intermittent currents. The waning phase of a storm results in development of bedforms and rapid deposition of a mud blanket. This process occurs ~ 5 km below the Gulf Stream or its rings and in several

other regions of the world. WHOI, Woods Hole, Mass. 02543, USA.

84:5528 Pattiaratchi, C.B. and M.B. Collins, 1984. Sediment

transport under waves and tidal currents: a ease study from the northern Bristol Channel, U.K. Mar. Geol., 56(1/4):27-40. Dept. of Oceanogr., University Coll., Singleton Park, Swansea SA2 8PP, S. Wales, UK.

84:5529 Sailer, A.H., 1984. Petrologic and geochemical

constraints on the origin of subsurface dolomite, Enewetak Atoll: an example of dolomitization by normal seawater. Geology, geol. Soc. Am., 12(4): 217-220.

A review of the evidence on dolomites in Eocene strata recovered from equatorial Pacific depths of 1250-1400 m suggests that the dolomite was precip- itated as the calcite was dissolved by cold, normal marine waters which percolated through the atoll at burial depths ~900 m sometime during or after the Middle Eocene. Dept. of Geol., Louisiana State Univ., Baton Rouge, La. 70803, USA. (hbf)

84:5530 Scrutton, R.A. and D.A.V. Stow, 1984. Seismic

evidence for Early Tertiary bottom-current cun- trolled deposition in the Charile Gibbs Fracture Zone. Mar. Geol., 56(1/4):325-334.

Buried, mounded and acoustically transparent sediment bodies banked up against a basement ridge at the eastern end of the Charlie Gibbs Fracture Zone (NE Atlantic) are interpreted as a type of contourite drift, probably of Eocene-?Palaeocene age. Possible sources for the bottom currents responsible for these drifts include Labrador Sea Water, Norwegian Sea Overflow Water, Antarctic Bottom Water or a Gulf Stream deep gyre system. The preferred source is an early development of Antarctic Bottom Water or an arm of a Gulf Stream Gyre flowing eastward through the fracture zone. Grant Inst. of Geol., Univ. of Edinburgh, West Mains Rd., Edinburgh EH9 3JW, UK.

84:5531 Singer, J.K. and J.B. Anderson, 1984. Use of total

grain-size distributions to define bed erosion and transport for poorly sorted sediment undergoing simtflated bhlturlmtion. Mar. Geol., 57(1/4):335- 359. Dept. of Geol., Rice Univ,, Houston, Tex. 77251, USA.

OLR (1984)31 (11) D. Submarine Geology and Geophysics 789

84:5532 Xia, Ming, Chenghui Zhang, Shao Liu, Liangji Wu,

Peiling Qin and Xiuyun Zhou, 1983. Studies on the sedimentation rate of the continental slope of the South China Sea. Scientia sin., (B)26(12): 1314-1322. Inst. of Geol., Acad. Sin., Beijing, People's Republic of China.

D130. Sediments (rocks, formations, type, composition, etc.)

84:5533 Abbott, Dallas, William Menke, Michael Hobart,

R.N. Anderson and R.W. Embley, 1984. Cor- related sediment thickness, temperature gradient and excess pore pressure in a marine fault block basin. Geophys. Res. Letts, 11(5):485-488.

In the surficial sediment of a fault block basin in the Guatemala Basin the temperature gradient is smaller and the excess pore pressure gradient is more negative in areas of thinner sediment possibly due to downward pore water advection within the sediments. Flow velocities are 10 9 to 10 -s m/s in the thinnest sediments and much less in the thickest sediments; sediment physical properties and pore water chemistry also support this interpretation. As the conductive heat flow of the basin as a whole is less than one-third that predicted by seafloor spreading models, the oceanic basement may be the site of a vigorous hydrothermal circulation system. Pore water advection in the sediments may be driven by this larger scale circulation. Coll. of Oceanogr., Oregon State Univ., Corvallis, Oreg. 97331, USA.

84:5534 Anderson, J.B., C.F. Brake and N.C. Myers, 1984.

Sedimentation on the Ross Sea continental shelf, Antarctica. Mar. Geol~ 57(1/4):295-333.

The great bulk of terrigenous sediments blanketing the Ross Sea region has been introduced by the marine portions of ice sheets or floating ice into water depths in excess of 400 m. Cores and samples provide evidence of several advances of the West Antarctic Ice Sheet producing glacial troughs and a widespread lodgement till facies. Modern deposits consist largely of biogenic sediments and reworked glacial debris; siliceous mud ooze occurs in areas of vigorous upwelling. The source for the terrigenous silts and clays, which in surface sediments are more abundant than in basal tills, remains uncertain. Dept. of Geol., Rice Univ., Houston, Tex. 77251, USA. 0abf)

84:5535 Ashmore, Stanley and S.P. Leatherman, 1984.

Holoome sedimentation in Port Royal Bay, Bermuda. Mar. Geol, 56(1/4):289-298. Minerals Management Serv., Eagle River, AK 99577, USA.

84:5536 Bornhold, B.D. and A. Guilcher (eds.), 1984. Special

issue. Sedimentation on high-latitude continental shelves. Mar. Geol~ 57(1/4):1-359; 12 papers.

It is only within the last decade or so that much research has been devoted to the inhospitable, complicated environments and deposits of high- latitude waters. Descriptions of cold-water shelf sediments from representative geographic areas included here were originally presented at the 1982 Hamilton, Ontario, XIth International Association of Sedimentologists Meeting. A model study of glacimarine processes defines 8 different regimes and includes an extensive bibliography; another study reviews active processes in the Weddell and Barents seas and fjords of Spitsbergen. North American studies treat Vancouver Island, the Muir Inlet (Alaska), a portion of the St. Lawrence Estuary, the Canadian seaboard, and the Grand Banks of Newfoundland. Other areas of research are the western European Quaternary deposits off Norway and the Celtic Sea and the recent sediments of the Antarctic seafloor and Ross Sea. (hbf)

84:5537 Bornhold, B.D. and C.J. Yorath, 1984. Surfidal

geology of the continental shelf, northwestern Vancouver Island. Mar. Geol., 57(1/4):89-112. Pacific Geosci. Centre, Geol. Surv. of Canada, Sidney, BC V8L 4B2, Canada.

84:5538 Carlson, R.L., C.H. Schaftenaar and R.P. Moore,

1984. Causes of compressiona~wave anis~ropy in carbonate--hearing, deep-sea sediments. Geo- physics, 49(5):525-532.

Velocity measurements in 3 mutually perpendicular directions through samples collected from DSDP Site 516 on the Rio Grande Rise indicate that velocity anisotropy is neither strongly correlated with density and mean velocity nor a preferred orientation of the c-axes of calcite crystals, but appears to be causally related to bedding. The increase of anisotropy with depth of burial suggests the influence of compaction and diagenesis. Dept. of Geophys. and Geodynam. Res. Prog., Texas A&M Univ., College Station, Tex. 77843, USA. (hbf)

790 D, Submarine Geology and Geophysics OIR (1984) 31 (t 1)

84:5539 Chapman, N.R., lan Barrodale and C.A. Zala, 1984.

Measurement of sound-speed gradients in deep- ocean sediments using l~ deconvolution techniques. IEEE Jl ocean. Engng, OE-9(1):26-30. Defence Res. Estab. Pacific, FMO Victoria, B.C. V0S 1B0, Canada.

84:5540 Duin, E.J.T., C.S. Mesdag and P.T.J. Kok, 1984.

Faulting in Madeira Abyssal Plain sediments. Mar. Geol., 56(!/4):29%308.

High-resolution seismic data reveal faults in the sediments of the Madeira Abyssal Plain (MAP) and the Nares Abyssal Plain (NAP). Most of the data are from the MAP, where faulting appears to be confined to particular locations. Individual faults cannot be traced from one seismic section to another. A positive correlation exists between the concentration of faults and the maximum sediment thickness. The faults apparently are related to unknown processes which have been active for a long period of time. Geol. Surv. of the Netherlands, P.O. Box 157, 2000 AD Haarlem, Netherlands.

84:5541 EI-Sayed, M.Kh., 1984. Reefai sediments of AI-

Ghardaqa, northern Red Sea, Egypt. Mar. Geol., 56(1/4):259-271. Alexandria Univ., Dept. of Oceanogr., Alexandria, Egypt.

84:5542 Louda, J.W. and E.W. Baker, 1984. Perylene

occurrence, alkylation and possible sources in deep--ocean sediments. Geochim. cosmochim. Acta, 48(5): 1043-1058.

Perylene is a naturally occurring aromatic hydrocarbon formed under anoxic conditions from biological sources. More than 80 DSDP sediment samples from the Guaymas Basin (Gulf of Cali- fornia) were analyzed; perylene was most abundant in anoxic diatomaceous sediments which were deposited beneath highly productive waters. Gen- erally, only the unsubstituted parent molecule is found in thermally immature sediments but deeper sediments with higher in-situ temperatures (>30°C) contained increasing amounts of Ct to C3 substi- tution. Perylene in marine sediments may be derived from sulfide-sensitive microaerophilic benthic mi- crobes and reflects the depositional environment and thermal history. Coll. of Sci., Florida Atlantic Univ., Boca Raton, Fla. 33431, USA. (bwt)

84:5543 Qiu, Chuanzhu, 1983. A study on the characteristics

and distribution of ferromanganese sediments and

volcanic debris sediments in the South China Sea. Tropic Oceanol., 2(4):269-277. (In Chinese, Eng- lish abstract.) South China Sea Inst. of Oceanol., Acad. Sin., People's Republic of China.

84:5544 Shanmugam, G. and R.J. Moiola, 1984. Eustatic

control of calciclastic tnrbidites. Mar. Geol., 56(1/4): 273-278.

By establishing the relationship between sea-level changes and the timing of potential deep-sea carbonate reservoir facies of turbidity current and debris flow origin, their occurrence may be predicted prior to drilling. Compilation of published data suggests that throughout the Phanerozoic most calciclastic turbidites correspond to lowered sea level. The data also suggest a possible lowstand of sea level during the Late Cretaceous. Mobil Res. and Develop. Corp., Box 819047, Dallas, Tex. 75381, USA.

84:5545 Stubblefield, W.L., D.W. McGrail and D.G. Kersey,

1984. Recognition of transgressive and post- transgressive sand ridges on the New Jersey continental shelf. (Discussion [by D.J.P. Swift, T.F. McKinney and L. Stahl] and reply papers follow.) Spec. Publs Soc. econ. Paleont. Miner., Tulsa, 34:1-41; 3 papers.

Theories of ridge origins on shelves are reviewed. Detailed bathymetry and vibracore data analysis reveal that the sand ridges off the New Jersey coast consist of 3 sets--nearshore and shoreface connected ridges intersecting the coast at 15-30 °, a similar set of outer, oblique ridges, and a mid-shelf ridge set paralleling the coast. Stubblefield et al. suggest that the coast-oblique sets formed as post-transgressive features and that the coast-parallel ridges were barrier ridges submerged by rising seas. Swift et al. discuss alternate interpretations. NOAA, Natl. Sea Grant Coll. Program, 6010 Executive Blvd., Rock- ville, Md. 20852, USA. (hbf)

84:5546 Sutherland, H.E., S.E. Calvert and R.J. Morris, 1984.

Geochemical studies of the Recent sapropel and associated sediment from the Hellenic Outer Ridge, eastern Mediterranean Sea. I. Mineralogy and chemical composition. Mar. Geol., 56(1/4): 79-92.

Black layers of highly organic clays in a single gravity core were analyzed and found to be similar in mineralogy and geochemistry to the 'associated marl ooze and calcareous clay.' Sapropel accumulation rates were 3-5 times faster than those of the


ooze and clay; the organic matter appears to have a marine origin. High post-glacial runoff in the Holocene and Pleistocene caused increased marine primary productivity; the resultant increased carbon flux to the bottom could have led to sapropel formation. Anoxia might have been involved. Inst. of Oceanogr. Sci., Wormley, Godalming, Surrey GU8 5UB, UK. (mjj)

84:5547 Tillman, R.W. and C.T. Siemers (eds.), 1984.

Silicieiastic sheff sediments. (Symposium, Den- ver, 1980.) Spec. Pubis Soc. econ. Paleont. Miner., Tulsa, 34:268pp; 12 papers.

Much of the material included here was originally presented at a 1980 symposium on shelf sandstones by the Society of Economic Paleontologists. The first section of reports deals with interpretation of modern shelf sand ridges off New Jersey; the second section describes Cretaceous shelf sediments of the Rocky Mountain interior seaway of Montana, Wyoming, Colorado, and Alberta; the third section centers upon Texan Cretaceous shelf sandstones. A final paper considers the Proterozoic Wishart For- mation of northeastern Canada. (hbf)

D140. Submarine hydrology (springs, hydrothermal deposits, etc.)

84:5548 Bischoff, J.L. and R.J. Rosenbauer, 1984. The

critical point and two-phase boundary of seawater, 200-500°C. Earth planet. Sci. Letts, 68(1): 172-180.

The boundary was determined by isothermal de- compression of fully condensed seawater in the range 200-500°C. The pressure at which phase separation occurred for each isotherm was determined by comparing the refractive index of fluid removed from the top and bottom of the reaction vessel. The critical point was in the range 403-406°C and 285-302 bar. As the two-phase boundary defines the maximum temperature of seawater circulating at depth in the oceanic crust, it puts a limit of ~390°C for seawater circulating near the seafloor at active ocean ridges (2.5 km water depth), and ~465°C at the top of a magma chamber (2 km below the seafloor). USGS, Menlo Park, Calif. 94025, USA.

84:5549 Campbell, A.C. and J.M. Gieskes, 1984. Water

column anomalies associated with hydrothermai activity in the Guaymus Basin, Gulf of California. Earth planet. Sci. Letts, 68(1):57-72.

Guaymas Basin's semi-enclosed setting 'allows water column anomalies to increase to relatively high values': large masses of fine suspended particulates 100-300 m above chimneys and mounds, potential temperature anomalies ~0.010-0.020C °, particulate Mn increasing from ~3 nmol/kg at ~1000 m to 100-150 nmol/kg in the bottom nepheloid layer and in the suspended particulates, a 'silica anomaly of 10-15 ~mol relative to other Gulf of California deep basins,' and O2 anomalies ~5 ftmol relative to other areas. About 10-12 m3/s of hydrothermal fluids are injected into the basin. Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA. (ihz)

84:5550 Fachtbauer, Hans, D.K. Richter, Joachim Wachter

(comment) and K.J. Hsll (reply), 1984. Forum. [Discussion of] 'Neptunic dikes and their relation to hydrodynamic circulation of submarine hydrothermal systems.' Geology, geol. Soc. Am., 12(4): 193-256.

84:5551 GaUinatti, B,C., 1984. Initiation and collapse of active

circulation in a hydrothermal system at the Mid-Atlantic Ridge, 23°N. J. geophys. Res., 89(B5):3275-3289.

'Altered rocks ranging from slightly fractured gab- bro to quartz-chlorite-sulfide breccias...[show] three stages of alteration which record the cooling of a hydrothermal system.' Geochemistry was done on samples collected by dredge and submersible south of the Kane Fracture Zone. Succession of alteration stages occurred spatially as well as temporally as the system evolved and then collapsed. Union Oil Geothermal, Box 6854, Santa Rosa, Calif. 95406, USA. (ecs)

84:5552 Marchig, Vesna, Heinrich Gundlach and Harald

Backer, 1984. Geochemical indication in deep--sea sediments for hydrothermal discharge. Mar. Geol., 56(1/4):319-323.

The total content of hydrothermal precipitates within a sediment can be used as an indicator for the proximity of hydrothermal discharge, as they increase rapidly toward the center of hydrothermal discharge. Precipitates can be determined by quick and simple shipboard determination of CaCO 3 or the sum of Fe and Mn. Fed. Inst. for Geosci. and Nat. Res., P.O. Box 510153, D-3000 Hannover 51, FRG.

84:5553 Norton, D.L., 1984. Theory of hydrothermal systems.

A. Rev. Earth planet. Sci, 12:155-177.

792 D. Submarine Geology and Geophysics OLR (1984) 31 (11)

This paper reviews the processes that comprise the basis of hydrothermal system theory; the theory mathematically portrays the redistribution of mass and energy by circulating fluids. The most active hydrothermal systems are caused by magma-induced thermal anomalies in the vicinities of magma chambers and batholiths; however, 'any thermal perturbation in fluid-rich rocks' (crust) generates hydrothermal activity. Resultant processes, both chemical and physical, and the interactions among them (leading gradually toward thermodynamic equilibrium and cessation of activity) are described in detail. Further study of active and fossilized systems (alteration patterns vary tremendously) will lead to improved mathematical formulations. Dept. of Geosci., Univ. of Arizona, Tucson, Ariz. 85721, USA. (sir)

D170. Historical geology, stratigraphy

84:5554 Ben Ismail-Lattrache, K. and C. Bobier, 1984.

Evolution of Palaeogene marine paleo--environments on the western borders of the Sicilian Channel and their relation with the fluctuations of the world puieo-ocean. Mar. Geol., 55(3/4): 195- 217. (In French, English summary.)

A study of benthic and planktonic Foraminifera in Middle Eocene to Middle Miocene clays on the flanks of the Jebel Abderrahman anticline enables interpretation of the Palaeogene series of the Cap Bon anticline. Eocene Cap Bon marine environments are placed just below the hinge line of the Hulk E1 Menzel platform under a temperate- to-tropical paleoclimate. The Reineche calcareous clay is positioned at a time of high sea level. The Fortuna Sandstone formed Mid- to Late Paleogene, during a period of worldwide ocean cooling and lowered seas. The climatic and tectonic evolution of the Oligocene also is reviewed. Includes micrographs. Lab. de Biostratigr., Fac. des Sci. de Tunis, Campus du Belvedere, 1060 Tunis, Tunisia. (hbf)

84:5555 Bohor, B.F., E.E. Foord, P.J. Modreski and D.M.

Triplehorn, 1984. Mlneruiogic evidence for an impact event at the Cretacemm-Tertiary boundary. Science, 224(4651):867-869.

A thin claystone layer dated at the C-T boundary and containing anomalously high iridium values was found in rocks from eastern Montana. The layer contains 'shock-metamorphosed quartz with (1) multiple sets of planar features indexing to specific

crystallographic planes, (2) reduced refractive in- dices, (3) asterism, and (4) traces of the high-pressure mineral stishovite.' These features are typical of shocked quartz associated with known meteorite impact craters. USGS, Box 25046, Denver, Colo. 80225, USA. (msg)

84:5556 Boyle, E.A., 1984. Cadmium in benthic Foraminifera

and abyssal hydrography: evidence for a 41 kyr obliquity cycle. Geophys. Monogr. Am. geophys. Un., 29(Maurice Ewing Ser. 5):360-368.

The Cd/Ca ratio in fossil benthic foraminifers in cores covering the glacial/interglacial transition in the western North Atlantic and a 285 kyr record on the Rio Grande Rise was used to trace deep ocean circulation patterns. Cd distribution is similar to P distribution and therefore can be used as a 'proxy for [bottom water] nutrient distributions.' Nutrient concentrations in the North Atlantic Deep Water were about twice as high 18,000 yr ago than at present, suggesting a 'substantial diminution of NADW flux relative to southern water sources, but not with a complete cessation of NADW." A strong 41 kyr fluctuation in NADW flow seen in the Rio Grande Rise record is interpreted as a consequence of 'obliquity-induced summer insolation variations on the ice cover of the NADW formation areas.' Dept. of Earth, Atmos. and Plan. Sci., MIT, Cambridge, Mass. 02139, USA. (msg)

84:5557 Bukry, David, 1984. Paleogene palaoceanography of

the Arctic Ocean is constrained by the Middle or Late Eocene age of USGS Core FI-422: evidence from smcoflagellates. Geology, geol. Soc. Am., 12(4): 199-201.

Light microscope observations on core samples from the floor of the Arctic Ocean under 2049 m of water reveal the presence of Eocene and Eocene or Oligocene silicoflagellate guide species, but no Paleocene siliceous microfossils. Generic ratios of silicoflagellates also suggest an age younger-than Paleocene. It is concluded that previous inferences of Paleocene marine conditions and the timing of Arctic silica deposition are erroneous. USGS, Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA. (hbf)

84:5558 Carr, P.F., B.G. Jones, B.G. Quinn and A.J. Wright,

1984. Toward an objective Phanerozoic time scale. Geology, geol. Soc. Am., 12(5):274-277.

A new, less subjective method for constructing a time scale using a 'piecewise linear regression model

OLR (1984) 31 (1 I) D. Submarine Geology and Geophysics 793

of radiometric age on a variable calculated from biostratigraphic data' is described. The method relies upon objective mathematical techniques; the results are reproducible, and, given sufficient controUed biostratigraphic data, can be extended to any part of the time scale. To illustrate the method, the duration of each Phanerozoic system is calculated. Dept. of Geol., Univ. of Wollongong, P.O. Box 1144, Wol- longong, NSW Australia 2500. (hbf)

84:5559 Dingle, R.V. and Q.B. Hendey, 1984. Late Mesozoic

and Tertiary sediment supply to the eastern Cape Basin (SE Atlantic) and palaeo-drainage systems in southwestern Africa. Mar. Geol., 56(1/4):13- 26.

Geomorphic, sedimentological, palaeontological, and zoological data support the hypothesis that there have been major changes in the drainage systems of the modern Orange and Olifants rivers. Since the Late Cretaceous, major drainage exit points have shifted to the north; the shifts were related to periods of lowered sea level and aridity as well as to possible disruption of river channels by Late Cretaceous igneous intrusions. Mar. Geosci. Unit, Univ. of Cape Town, Rondebosch 7700, South Africa. (hbf)

84:5560 Dowsett, H.H., 1984. Documentation of the foram-

iniferal Santonian-Campanian boundary in the northeastern Gulf of Mexico. J. foram. Res., 14(2): 129-133. Includes 18 micrographs. Dept. of Geol., George Washington Univ., Washington, DC 20052, USA.

84:5561 Fanucci, Francesco, Marco Firpo, Mauro Piccazzo

and Lorenzo Mirabile, 1984. The pllo-Quater- nary in the Ligurian Sea: thickness and conditions of sedimentation. Mar. Geol, 55(3/4):291- 303. (In French, English abstract.) Ist. di Geol. dell'Univ., Corso Europa 30, Genova, Italy.

84:5562 Gottfried, M.D., P.S. Doyle and W.R. Riedel, 1984.

Advances in ichthyollth stratigraphy of the Pacific Ncogene and Oligocene. Micropaleontology, 30(1):71-85.

To improve the resolution of ichthyolith stratigraphy in the Pacific Neogene and Oligocene, 12 new taxa are described, and their ranges are determined in Giant Piston Core 3 and in 104 samples. The stratigraphic utilization of these microfossils is improved by assessing the relative reliability of earliest and latest occurrence data in correlated sequences. This procedure allows for less subjective

decisions regarding the stratigraphic dependability of individual forms and provides a basis for choosing between conflicting correlation lines. Includes mi- erographs. Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA.

84:5563 Hallam, Anthony, 1984. Pre-Quaternary sea level

changes. A. Rev. Earth planet. Sci., 12:205-243.

A review of the evidence for eustatic changes of sea level, inferred from the distribution of marine deposits, facies analysis, seismic stratigraphy, and biostratigraphic correlations, suggests that since the Late Ordovician sea levels have declined from a high of ~600 m above present levels. Major oscillations included a Late Paleozoic fall and a Cretaceous rise to ~350 m higher than present. Tectonoeustatic factors modifying the volume of the ocean basins, rather than glacioeustatic factors, appear to underlie these changes. Dept. of Geol. Sci., Univ. of Bir- mingham, Birmingham B I5 2TT, UK. (hbf)

84:5564 McManus, D.A. and J.S. Creager, 1984. Sea-level

data for parts of the Bering-Chukchi shelves of Beringia from 19,000 to 10,000 14C yrBP. Quat. Res., 21(3):317-325.

A reevaluation of available radiocarbon-dated cores from the area of the Pleistocene land bridge connecting Asia and North America suggests that sea level rose approximately 6 m/103 yr with only minor regressions for the interval studied. Sea level is placed at -68 m about 19,000 yrBP, -55 m about 16,000 yrBP and -30 m at 12,000 yrBP. The net effect of the rise has been to halt migration of land species and to facilitate migration of marine species. Sch. of Oceanogr., Univ. of Washington, Seattle, Wash. 98195, USA. (hbf)

84:5565 Muerdter, D.R., J.P. Kennett and R.C. Thunell,

1984. Late Quaternary sapropel sediments in the eastern Mediterranean Sea: faunal variations and chronology. Quat. R es., 21(3):385-403.

Analysis of the planktonic foraminiferal content of 9 deep basin sapropel layers reveals the presence of 3 distinct, climatically-related clusters. Although sedimentation on the Mediterranean Ridge has remained relatively constant over the last 127,000 yr, analysis of 14 cores suggests that basin sedimentation rates have fluctuated markedly. Approximate ages are given for the sapropel layers. AMOCO Production Co., 1340 Poydras St., P.O. Box 50879, New Orleans, La. 70150, USA. (hbf)

794 D. Submar ine Geo logy and Geophysics O LR (1984) 31 I l I )

84:5566 Pantin, H.M. and C.D.R. Evans, 1984. The Qua-

ternary history of the central and southwestern Celtic Sea. Mar. Geol., 57(1/4):259-293.

Samples and cores obtained from 1360 sites and 10,600 km of acoustic line were used to improve the bathymetry and supplement available data on sediments and stratigraphy. The Late Pliocene/Early Pleistocene Little Sole Formation, consisting of fluvial deposits and lesser amounts of shallow marine clastics, is overlain by Late Devensian/Early Flandrian Melville Formation tidal deposits, and topped by a gravelly lag pavement and mobile sandy sediments. Ice-rafted mounds of material, boulders, and scattered outcrops of till are also present. In addition, there is evidence of a number of intervals of marine planation and subsidence of the outer shelf area. British Geol. Survey, Nicker Hill, Key- worth, Nottingham NGI2 5GG, UK. (hbf)

84:5567 Patmore, S.J. (comment), D.M. Angstadt, J.A.

Austin and R.T. Buffler (reply), 1984. Forum. Comment and reply on 'Deep-sea erosional unconformity in the southeastern Gulf of Mexico.' Geology, geol. Soc. Am., 12(4):248-249.

84:5568 Pisias, N.G. et al., 1984. High resolution stratigraphic

correlation of benthic oxygen isotopic records spanning the last 300,000 years. Mar. Geol., 56(1/4): 119-136.

The oxygen isotope composition of Foraminifera can be used as a basis for high resolution stratigraphy. Benthic oxygen isotope records from 7 piston cores taken in several oceans were correlated by two independent methods: Shaw's (1964) graphic correlation procedure and Martinson's et al. (1982) inverse procedures/nonlinear mapping function. Stratigraphic correlations produced by these methods agreed closely and suggest a resolution of 2000 to 4000 years. Sell. of Oceanogr., Oregon State Univ., Corvallis, Oreg. 97331, USA. (mjj)

84:5569 Ross, C.R., 1984. Hyalinea /m/t/flea and its Late

Quaternary paloodimatie implications: Strait of Sicily. J. foram. Res., 14(2):134-139.

Analysis of a suite of Late Quaternary cores from the Strait of Sicily indicates that abundance of H. balthica has not always been indicative of cooler water conditions. Although high frequencies of the species are present in material from interglacial stages 7 and 5 and low frequencies characterize glacial stages 6 and 4, abundances also occur in both

interstadial stage 3 and glacial stage 2 with a decrease in numbers during interglacial stage 1. Includes 16 micrographs. Grad. Sch. of Oceanogr., Univ. of Rhode Island, Narragansett, RI 02882, USA. (hbf)

84:5570 Ruddiman, W.F. and A. McIntyre, 1984. Ice-age

thermal response and climatic role of the surface Atlantic Ocean, 40°N to 63°N. Bull. geol. Soc. Am., 95(4):381-396.

The authors examine oceanic thermal response in relation to climate change based on SST and 8~80 (~ice volume) records for the past 250 kyr, and their correlation with the Earth's orbital periods (100 kyr eccentricity, 41 kyr obliquity, and 23 kyr precession). Analyses support the authors' earlier suggestion that the mid-latitude North Atlantic 'acts primarily as a moisture amplifier of continental ice sheet growth and decay at the 23-kyr period'; oceanic heat transfer is probably less critical at these latitudes (40°N-50°N). However, 'temperature feedback is most likely to affect high-latitude marine ice at the 41-kyr rhythm and all ice masses at the 100-kyr rhythm.' While feedback amplitudes remain uncertain, these general relationships hold 'together quite coherently through the period investigated.' Lamont-Doherty Geol. Observ., Palisades, N.Y. 10964, USA. (slr)

84:5571 Stanley, S.M., 1984. Temperature and biotic crises in

the marine realm. Geology, geol. Soc. Am., 12(4):205-208.

Examples from the Phanerozoic geologic record are cited which support climatic change, and not areal restriction of the seafloor, as a major cause of marine mass extinctions. Evidence for this argument includes the concentration of extinctions within the tropics, which offer no further latitudinal escape; the protracted, pulsational character of some extinctions; and the coincidence of several mass extinctions with known cooling intervals. Dept. of Earth and Planet. Sci., Johns Hopkins Univ., Baltimore, Md. 21218, USA. 01bf)

84:5572 Sugisaki, Ryuichi, 1984. Relation between chemical

composition and sedimentation rate of Pacific ocean-floor sediments deposited since the Middle Cretaceous. Basic evidence for chemical constraints on depositional environments of ancient sediments. J. Geol., 92(3):235-259.

Geochemical examination of Pacific DSDP sediments from different environments demonstrates that the distribution of hydrogenous elements (Mn,

OLR (1984) 31 (11 ) D. Submarine Geology and Geophysics 795

Co, Ni) is related to bulk sedimentation rate and that their weight relative to TiO 2 in surface sediments has not changed since the middle Cretaceous. It is proposed that hydrogenous element:TiO 2 ratios be used as new indicators of the sedimentation rate of terrigenous materials. Evaluation of ancient sedimentary rocks, geosynclinal cherts, and subduction at the Japan Trench suggests that ophiolite suites and orogenic belt cherts are not necessarily generated at mid-ocean ridges. Dept. of Earth Sci., Nagoya Univ., Chikusa, Nagoya, 464, Japan. (hbf)

84:5573 Vorren, T.O., Morten Hald and Elsebeth Thomsen,

1984. Quaternary sediments and environments on the continental shelf off northern Norway. Mar. Geol., 57(1/4):229-257.

Evidence from almost 200 gravity cores demonstrates the change from the tills, laminated clays, and pebbly pelites deposited during the Weichselian to a period beginning 13,000 yrBP when winnowing began on the deep banks and sandy pelites formed in the troughs. Further changes from arctic to boreal faunas, high-energy winnowing, and high rates of accumulation marked the intrusion of Atlantic waters at the start of the Holocene. More recently winnowing has diminished; trough deposits consist largely of bouldery and pebbly sand, sand, and sandy mud distributed by bottom currents. Inst. of Biol. and Geol., Univ. of Tromso, P.O. Box 3085, N-9001 Tromso, Norway. (hbf)

D180. Paleontology (see also E-BIOLOGICAL OCEANOGRAPHY)

84:5574 Balsam, W.L., E.S. Posmentier (comments) and D.

Schnitker (reply), 1984. Comments on spectral analysis of core data. Palaeogeogr. Palaeo- climatol. PalaeoecoL, 45(3/4):369-374.

84:5575 Benson, R.H., 1983. Biomechanical stability and

sudden change in the evolution of the deelv-sea ostracode Poseidonamicus. Paleobiology, 9(4): 398-413. Smithsonian Inst., Washington, DC 20560, USA.

84:5576 Berggren, W.A. and R.E. Casey (organizers), 1983.

Symposium on tempo and mode of evolution from mlcropaleontological data. (Montreal, 5-7 August 1982.) Paleobiology, 9(4):326-428; 10 papers.

These 10 papers present data on fossil radiolarians, foraminiferans and benthic ostracodes which 'bear on fundamental questions of rates and patterns in evolution.' Evidence is presented for both gradual and punctuated evolution, as well as support for other modes (equal allopatric, sympatric and parapatric speciation; hybridization; and character displacement). The importance of biogeographical and ecological data is discussed and a new statistical technique, 'Eigenshape analysis,' is presented. (mjj)

84:5577 Casey, R.E., C.R. Wigley and A.M. Perez-Guzm~in,

1983. Biogeographie and ecologic perspective on polycystine radioladan evolution. Paleobiology, 9(4):363-376.

Zoogeographical and ecological data on extant and fossil radiolarian species are used in a study of Stichocorys and Lamprocyrtis lineages; their evolution probably involved 'aUopatric speciation as peripheral isolates,' although sympatric speciation and hybridization also may have occurred in some cases. Timing and causes of macroevolution (at the family level) are discussed; global cooling may have been involved. Dept. of Geol., Rice Univ., Houston, Tex. 77251, USA. (mjj)

84:5578 Ekdale, A.A. and R.G. Bromley, 1984. Comparative

ichnology of shelf-sea and deep--sea chalk. J. Paleont., 58(2):322-332.

Shelf-sea (epicratonic) chalks are distinguished from deep-sea (abyssal) chalks by the presence of abundant megafossils, burrow flints, burrow systems, and omission surfaces; cycheity; borings in hard grounds and macrofaunal shells; and associated pyrite, glauconite, and phosphate deposits. Increasing epicratonic water depths are characterized by a shift from Thalassinoides-dominated trace fossils to an abundance of Zoophycos. Deep-sea chalks are dominated by Chrondrites, Planolites, and Zoophycos. Dept. of Geol. and Geophys., Univ. of Utah, Salt Lake City, Utah 84112, USA. (hbf)

84:5579 Empson-Morin, K.M., 1984. Depth and latitude

distribution of Radiolaria in Campanian (Late Cretaceous) tropical and subtropical oceans. Micropaleontology, 30(1):87-115.

Radiolarians in 237 samples from DSDP sites and surface sites varied in morphotype, diversity, and abundance. Of the 146 morphotypes, only 2 occurred in all samples and 1 form was restricted to high latitudes. Like modern Radiolaria, the maximal diversity, abundance and number of forms were


present in deep waters of the low-latitude open oceans. Within individual basins, numbers of spec- imens increased with depth. Includes 25 micrographs. Prog. in Geosci., The Univ. of Texas at Dallas, Richardson, Tex. 75080, USA. (hbf)

84:5580 Golubic, S. et al., 1984. Microbial endoliths: a benthic

overprint in the sedimentary record, and a paleobathymetric cross-reference with Forami- nifera. J. Paleont., 58(2):351-361.

Microbial endoliths leave species-specific borehole tracings in carbonate particles which have settled to the bottom in all marine environments. Discussed here is the usefulness of fossil borehole tracings in Foraminifera as paleobathymetric indicators. As microbial endoliths and their hosts have independent depth ranges, 'their co-occurrence provides a basis for a more refined cross-reference for paleobathymetric indication than either alone.' Includes micrographs. Dept. of Biol., Boston Univ., Boston, Mass., USA. (mjj)

84:5581 Kellogg, D.E., 1983. Phenology of morphologic

change in radiolarian Hneages from deep-sea cores: implications for macroevolution. Paleobi- ology, 9(4):355-362.

Data on the time distribution, or phenology, of morphologic change in two species of Eucyrtidium are not consistent with a basic premise of the punctuated equilibrium theory: changes in the size differential between the two species occurred as the result of many small steps during neosympatry, not as the result of a major change 'early in the process.' Inst. for Quat. Stud., Univ. of Maine, Orono, Maine 04469, USA. (mjj)

84:5582 Lazarus, David, 1983. Speciation in pelagic Protista

and its study in the planktonic microfossil record: a review. Paleobiology, 9(4):327-340.

The punctuated equilibrium hypothesis is not the only possible pattern of speciation in planktonic protists; other possibilities include parapatric, 'equal' allopatric, and hybridization models. Use of deep- sea microfossil data in testing speciation patterns is discussed and effects on apparent speciation patterns caused by species structures, reproductive behavior, etc. are pointed out. The best means of testing evolutionary hypotheses are considered and available evidence is reviewed. WHOI, Woods Hole, Mass. 02543, USA. (mjj)

84:5583 Loeblich, A.R. Jr. and Helen Tappan, 1984. Supra-

generic classification of the Foramlnlferida (Pro- tozoa). Micropaleontology, 30(1):1-70. Includes an index and 8 pages of references. Dept. of Earth and Space Sci., Univ. of Calif., Los Angeles, Calif. 90024, USA.

84:5584 Lohmann, G.P. and B.A. Malmgren, 1983. Equa-

torward migration of GloborotMia tmncatuli- noides ecopbenotypes through the Late Pleis- tocene: gradual evolution or ocean change? Paleobiology, 9(4):414-421.

Biogeographic differences in the shape of modern G. truncatulinoides are compared with Late Pleistocene fossils from the South Atlantic. A 'clear migration of certain morphotypes...toward lower latitudes' has been occurring during the last 700,000 years; no relationship to climatic change is apparent. This migration may be caused by some 'previously unmeasured, gradually changing' environmental factor or may represent a 'gradual evolution of environmental preferences.' WHOI, Woods Hole, Mass. 02543, USA. (mjj)

84:5585 Malmgren, B.A., W.A. Berggren and G.P. Lohmann,

1983. Evidence for punctuated gradualism in the Late Neogene Globorotalia tunffda lineage of planktonic Foraminifera. Paleobiology, 9(4):377- 389.

Test shape was analyzed in a detailed study of the transition of G. plesiotumida to G. tumida in material from the southern Indian Ocean. Throughout most of the stratigraphic sequence (10.4 myBP to the present) the lineage remained in relative stasis. Only during the brief period 5.6-5.0 myBP did the rapid morphologic changes occur which transformed one species into another, with no lineage branching. The authors term this evolutionary modality 'punctuated gradualism' and suggest it may be common in planktonic Foraminifera. Dept. of Paleont., Univ. of Uppsala, Box 558, S-751 22 Uppsala, Sweden. (mjj)

84:5586 Miller, M.F., A.A. Ekdale and M.D. Picard (eds),

1983/84. Trace fossils and paleoenvironments: marine carbon_ate, marginal marine terrigenons and continental terrigenous settings. (Two sym- posia in Spring 1983.) Special issue. J. Paleont., 58(2):283-597; 21 papers.

Papers presented by the SEPM's Trace Fossil Research Group at the AAPG-SEPM April 1983 meeting in Dallas and the Paleontological Society's


Pacific Section at the GSA's May 1983 regional meeting in Salt Lake City emphasize the increased interest in trace fossils and their influence on the sedimentary environment and the need for more research. The SEPM's Biogenic Structures in Car- bonates symposium evaluated the utility, selective preservation, and applicability of modem analogs to trace fossils found in rocks of Ordovician to Recent age representing abyssal to supratidal environments. The Paleontological Society's symposium on Trace Fossils and Bioturbation in Nonmarine Sedimentary Deposits treated similar considerations and demonstrated the value of careful, interpretive investigations of nonmarine fossil traces. (hbf)

84:5587 Palmer, A.R., 1984. The biomere problem: evolution

of an idea. J. Paleont., 58(3):599-611.

Palmer has defined 'biomeres' as biostratigraphic intervals of at least continental scale which include several biozones and are 'bounded by sharply defined extinction events.' The problem of the biomere is elucidated by examination of one Upper Cambrian biomere boundary, in which one group of trilobites are replaced by another. The extinction events at biomere boundaries have no apparent extraterrestrial cause, and may have been due to a rapid rise in the thermocline or widespread anoxia. Geol. Soc. of America, P.O. Box 9140. Boulder, Colo. 80301, USA. (mjj)

84:5588 Robaszynski, Francis, Mich61e Caron, J.M.

Gonzalez Donoso and A.A.H. Wonders (eds.), 1983/84. Atlas of Late Cretaceous giobotrun- canids. Revue Micropaldont., 26(3/4):145-305.

This description of the morphology, taxonomy, phylogeny, and biostratigraphy of some 210 species and 9 genera known from the Tethyan paleogeo- graphic realm completes the Atlas of Middle Cre- taceous Foraminifera (1979). Vertical distribution and phylogenetic relationships are shown on charts. In addition, 50 species are revised and 2 new species ( Globotruncana dupeublei and Globotruncanella minuta) are described. An 8-fold zonation of the Late Cretaceous and tentative correlations with other micro- and macropaleontological groups are proposed. Includes 54 plates and an index. (hbf)

D200. Gravity, geodesy, magnetism 84:5589

Chave, A.D., 1984. The Fr6chet derivatives of electromagnetic induction. J. geophys. Res., 89(B5):3373-3380.

The response functions for the fundamental toroidal and poloidal magnetic modes are Fr6chet differ- entiable in an L 2 norm for general conductivity structures and arbitrary source frequency/wavenumber morphology. Perturbation forms of the modal Green functions are used to examine the Fr6chet kernels for a seafloor controlled source and a Kelvin wave model. In both cases, the TM mode possesses superior resolution ability, especially for low relative conductivity contrasts at depth. Results suggest that induction by the ocean tides can see lithospheric structural details at depths of at least 50 km. Scripps Inst. of Oceanogr., La JoUa, Calif. 92093, USA.

84:5590 McFadden, P.L., 1984. Statistical tools for the

analysis of geomagnetic reversal sequences. J. geophys. Res., 89(B5):3363-3372. Res. Sch. of Earth Sci., Australian Natl. Univ., P.O. Box 4, Canberra, ACT 2600, Australia.

84:5591 Souriau, Annie, 1984. Geoid anomalies over Gorringe

Ridge, North Atlantic Ocean. Earth planet. Sci. Lefts, 68(1):101-114.

A '9-m height anomaly with a N-S lateral extension ~200 km' is deduced for the Gorringe Ridge from Seasat altimetric data. Seismicity and gravity anomalies are used in conjunction with previous geological, geophysical and petrological results to evaluate several models of the area's tectonics. Isostatic equilibrium, nascent subduction zone, uncompen- sated, locally heterogeneous, and non-isostatic models all are found unsuitable. A dynamical model incorporating mantle convection is suggested as a likely alternative. Dept. of Geol. Sci., Hoffman Lab., Harvard Univ., Cambridge, Mass. 02138, USA. (ihz)

84:5592 Swift, B.A. and H.P. Johnson, 1984. Magnetic

properties of the Bay of Islands Ophiuiite Suite and implications for the magnetization of oceanic crust. J. geophys. Res., 89(B5):3291-3308.

Weathered and metamorphosed extrusive basalts have a weak, secondary magnetization arising from oxidation and exsolution of ilmenite of unknown origin. Initial magnetization of the underlying sheeted dike complex appears to have been de- stroyed by hydrothermal alteration soon after formation. Magnetic intensity of gabbroic samples increases with degree of alteration; these units are unlikely to make a significant contribution to lineated magnetic anomalies. Studies suggest a model in which oceanic crust magnetization results

798 D. Submar ine Geo logy and Geophys ics O L R (1984) 31 (I 1 )

from an upper extrusive basalt source layer roughly 600 m thick, with no contribution from a deeper source layer recognizable. USGS, Woods Hole, Mass. 02543, USA.

D210. Heat flow

84:5593 Della Vedova, B., G. Pellis, J.P. Foucher and J.-P.

Rehault, 1984. Geothermal structure of the Tyrrhenian Sea. Mar. Geol., 55(3/4):271-289.

Heat flow measurements show good correlation with the magnetic signature of the basin. The Central Fault system separates the basin into two sections with different geothermal characteristics. The fault forms a boundary 'between a stretched crust (8-10 km thick)...to the southeast and a thicker continental crust...to the northwest.' Ist. di Min. e Geofis. Appl., Univ. degli Studi di Trieste, Viale R. Gessi, 4, 1-34123 Trieste, Italy. (ecs)

D240. Local or regional tectonics

84:5594 Aubouin, Jean, Jacques Azrma, Bernard Biju-Duval,

Jacques Bourgois, Alain Mascle and Marc Tardy, 1984. Subdoction and orogeny. The Barbade Accretionary Prism and the Middle America Trench subduction without accretion: two shallow tectonic responses to the subduction. C. r. Acad. Sci., Paris, (11)298(8):351-358. (In French, English abstract.)

84:5595 Beck, M.E. Jr. et al., 1984. Correlation between plate

motions and Cordilleran tectonics. (Symposium, San Francisco, 13-14 December 1982.) Special issue. Tectonics, 3(2):103-315; 12 papers.

The twelve papers here were drawn from 42 presented at this AGU symposium. Generally speak- ing the conference was to identify 'unmistakable correlations' with regard to orogenic events in the North American Cordillera and the known history of plate motions in the region. It was hoped that major changes in plate interactions would leave a clear record in the mountain geology. 'In retrospect, these were somewhat naive assumptions,' although several convincing correlations emerged. (fcs)

84:5596 Boccaletti, Mario, Rinaldo Nicolich and Luigi

Tortorici, 1984. The Calabrian Arc and the Ionian

Sea in the dynamic evolution of the central Mediterranean. Mar. Geol., 55(3/4):219-245.

Geophysical and structural analyses support a rigid-plastic deformation model by which the post- Tortonian evolution of the central Mediterranean produced continental crust. Major fracture zones delimit 3 main realms: an Ionian block constituting a Jurassic-? domain of thinned continental crust forming a basin unaffected by tectogenesis; a Pelagian realm of continental crust subjected to rifting and volcanism; and the Tyrrhenian Sea, interpreted as a megaextension fracture paralleling the direction of principal stress. Includes a fold-out color structural map. Dipt. di Sci. della Terra, Univ. di Firenze, 1-50121 Firenze, Italy. (hbf)

84:5597 Boucarut, Marc, J.-M. Broustet, Michel Clin and

J.Z. de Boer, 1984. Lower Cretaceous position of the Iberian Plate: the tectono-magmatic lineament of Madeira-Cornwall. C. r. Acad. Sci., Paris, (1I)298(7):303-306. (In French, English abstract.) Inst. de Geodynam., Univ. de Bor- deaux-Ill, 33405 Talence Cedex, France.

84:5598 Burrus, J., 1984. Contribution to a geodynamic

synthesis of the Provenepd Basin (northwestern Mediterranean). Mar. Geol,, 55(3/4):247-269.

Seismic and field data recently collected from the Provenqal Basin and Sardinia were used to ascertain the extension of the oceanic floor in the Gulf of Lions and the Ligurian Sea and to date oceanic accretion between the Upper Aquitanian and the Lower Burdigalian. The data provide a general framework for interpretation of the magnetics in the basin according to the Vine and Matthews hypothesis. Kinematics of the drifting of Corsica and Sardinia are discussed and the processes of oceanic accretion are examined. The mechanisms are compared with those reported in the marginal seas of the Western Pacific. Inst. Francais du Petrole, B.P. 311, 92506 Rueil-Malmaison Cedex, France.

84:5599 Choukroune, Pierre, Jean Francheteau and Roger

Hekinian, 1984. Tectonics of the East Pacific Rise near 12°50"N: a submersible study. Earth planet. Sci. Letts, 68(1):115-127.

Between 12°38" and 12°54"N, four main zones are defined: (1) an active volcanic zone in the central graben; (2) an active tectonic zone comprising the central graben and extending up to ~ 2 km from either side of the rise axis; (3) an inactive tectonic zone starting 2 km away from the axis and formed


by discontinuous horst and graben type structures; and (4) off-axis volcanoes (seamounts) located ( 2 0 km on either side of the rise axis. At 12°50"N, the active tectonic zone is extremely narrow and the deformation model is through fissuring. Includes bottom photos, cross-sections, schematics and a bathymetric map. Lab. de Geol. struct., Univ. de Rennes 1, 35042 Rennes Cedex, France.

$4:5600 Courtillot, V., J. Achache, F. Landre, N. Bon-

hommet, R. Montigny and G. F6raud, 1984. Episodic spreading and rift propagation: new paleomagnetic and geochronologic data from the Mar nascent passive margin. J. geophys. Res., 89(B5): 3315-3333.

Most basalt samples have a single stable magnetic component. Remanent direction of sites ( 1 Ma is consistent with the expected axial dipole direction; sites 1.35-2.25 Ma form a microblock that was rotated clockwise, probably between 1.3 and l Ma. The rotation is attributed to rift propagation. Spreading and rift propagation in Afar are episodic, leading to alternate 'effusive' and 'tectonic' phases that may be of general significance for accreting plate boundaries. Inst. de Phys. du Globe, Univ. Pards 6, France.

84:5601 Elston, W.E., 1984. Subduction of young oceanic

lithosphere and extensional orogeny in southwestern North America during Mid-Tertiary time. Tectonics, 3(2):229-250.

The evolution of the Basin and Range Province, which includes some of the highest mountains in North America, is explained in terms of extensional orogeny resulting from thinning and extension of the lithosphere. It is argued that this Mid-Tertiary orogeny represents a 'special case of continental backarc extension,' and that the thinning continental lithosphere was underplated by hot, buoyant ductile oceanic lithosphere from the overridden Farallon Plate which had converged with the American Plate. A decrease in the rate of convergence between the two plates may have affected the direction of absolute motion, enhanced the oceanward extension of the continental plate, and raised temperatures near its base to 1100°C. Dept. of Geol., Univ. of New Mexico, Albuquerque, NM 87131, USA. (hbf)

84:5602 Engebretson, D.C., A. Cox and G.A. Thompson,

1984. Correlation of plate motions with continental tectonics: Laramlde to Basin-Range. Tectonics, 3(2): 115=119.

Sierra Nevada plutonism ended and Laramide compression began during increasingly rapid convergence of the Farallon Plate with North America and during a moderate increase in the westward motion of North America. The end of the Laramide and beginning of widespread arc magmatism and extension correlates with slowing of both motions; spectacular slowing of the former is attributed to the decreasing age of the subducting Farallon Plate and thus to a change from negative to positive buoyancy. Transition from widespread arc-related magmatism and rapid extension to basaltic volcanism and moderate extension in the Basin and Range Province finds no ready explanation in plate motions of the Pacific basin. Oblique spreading in the Basin and Range Province accompanied lengthening of the San Andreas Fault as the Mendocino triple junction progressed northward. Dept. of Geol., Western Washington Univ., Bellingham, Wash. 98225, USA.

84:5603 Farrar, E. and J.M. Dixon, 1984. Overriding of the

Indian-Antarctic Ridge: origin of Emerald Basin and migration of Late Cenozoic volcanism in southern New Zealand and Campbell Plateau. Tectonophysics, 104(3/4):243-256.

Presented is an example of a subduction zone which has overridden a spreading center. The distribution of alkaline basaltic volcanic rocks indicates that mantle upwelling continues for tens of millions of years after being overridden. Underlying mantle upwelling continues 'either because of thermal inertia or because mantle convection is a primary, deep-seated process.' Dept. of Geol. Sci., Queen's Univ., Kingston, Ont. K7L 3N6, Canada. (amt)

84:5604 He, Guoqi, Shignang Wang, Guangzhen Cui and

Jian Shao, 1983. On the features of reactivation of the Sino-Korean Plate. Tectonophysics, 100(l/3): 119-130. Dept. of Geol., Beijing Univ., Beijing, People's Republic of China.

g4:5605 Henderson, L.J., R.G. Gordon and D.C. Engebret-

son, 1984. Mesozoic aseismic ridges on the Far a lion Plate and southward migration of shallow subduction during the Laramide orogeny. Tectonics, 3(2): 121-132.

It is proposed that an aseismic ridge of Late Jurassic and Early Cretaceous age on the Farallon plate was subducted beneath the United States Cordillera during the Laramide orogeny. The relative buoyancy of the aseismic ridge caused shallow subduction resulting in a magmatic lull 70-40 Ma in the existing near-trench magmatic arc and Laramide uplift and

800 D. Submarine Geology and Geophysics OLR (1984) 31 (11 )

faulting of crystalline basement 1000-1500 km inland from the trench. The timing and latitudinal limits of the subduction are similar to those of the Laramide orogeny and the magmatic lull in the western Cordillera. Because the N - N E trending aseismic ridge was moving NE relative to the North American plate, its point of collision with North America, and therefore the locus of shallow subduction, migrated southward with time, causing the well-documented southward migration of the magmatic lull. Dept. of Geol. Sci., Northwestern Univ., Evanston, Ill. 60201, USA.

84:5606 Jackson, H.R., G.L. Johnson, Eirik Sundvor and

A.M. Myhre, 1984. The Yermak Plateau: formed at a triple junction. J. geophys. Res., 89(B5): 3223-3232.

Dredge hauls, magnetic observations, heat flow data and seismic reflection and refraction data indicate a dual origin for the Yermak Plateau. North of 82°N the plateau is thick oceanic crust which formed in conjunction with the Morris Jesup Rise. South of 82°N the plateau 'is thinned continental crust formed by the initial tiffing process at a triple junction north of Greenland.' Bedford Inst. of Oceanogr., Dartmouth, NS B2Y 4A2, Canada. (msg)

84:5607 Jurdy, D.M., 1984. The subduction of the Faralion

Plate beneath North America as derived from relative plate motions. Tectonics, 3(2):107-113.

The motion of the Farallon Plate relative to North America is reconstructed back to the Late Mesozoic using relative plate motion data rather than hotspots. The preferred model predicts an increase in the subduction rate of the Farallon Plate, exceeding 150 mm/yr, with a direction almost due east and perpendicular to the continental margin. Duration of this nonoblique high-rate subduction correlates well with the Laramide Orogeny. This correlation must be regarded as only suggestive; probable errors, when combined and propagated through the relative motion circuit, may be of the order of the effect observed. Dept. of Geol. Sci., Northwestern Univ., Evanston, Ill. 60201, USA.

84:5608 Kasapoglu, K.E. and M.N. ToksOz, 1984. Tectonic

consequences of the collision of the Arabian and Emaslan plates: finite element models. Tecton- ophysics, 100(1/3):71-95.

Numerical models show that northward convergence of the Arabian and African plates alone cannot explain movements on all known faults. An additional driving force that would produce about 2

cm/yr westward motion of the Anatolian plate is required. With such a boundary condition added, the finite element models produce movements along five major faults (North Anatolian, East Anatolian, Dead Sea or Levant fracture, Tuz Golu and Ecemis) with current magnitudes and directions. Dept. of Earth Sci., Hacettepe Univ., Ankara, Turkey.

84:5609 Kayal, J.R., 1984. Microseismicity and tectonics at

the Indian/Pacific plate boundary: southeast Wellington Province, New Zealand. Geophys. Jl R. astr. Soc., 77(2):567-592.

Results of a microearthquake study of North Island, New Zealand, support the tectonic picture derived from the long-term macroseismicity. The earthquakes define a fairly continuous band of activity along the strike of the subducted Pacific plate and are concentrated at depths of 20-40 km. Differences, however, are observed between sections of the fault which appear to be locked and those which are unlocked, and the foci deepen toward the northwest. Focal mechanisms are consistent with those found in other regions of plate convergence and with the regional tectonics. Geophys. Div., Geol. Surv. of India, !15 Park St., Calcutta 700016, India. (amt)

84:5610 Liu, Zhaoshu, Shukang Yang, Shanmou He, Ciliu

Huang and Serqiang Chen, 1983. Continental margin spreading of the South China Sea and the cycle of evolution of marginal seas. Tropic OceanoL, 2(4):251-259. (In Chinese, English summary.) South China Sea Inst. of Oceanol., Acad. Sin., People's Republic of China.

84:flill Mart, Yossi, 1984. The tectonic regime of the

southeastern Mediterranean continental margin. Mar. Geol., 55(3/4):365-386.

The continental margin off Israel and Sinai is transected by a series of NW-SE-trending faults. Evidence of lateral displacements along these faults is presented. The faults off Israel terminate at the eastern edge of the Levant Basin, whereas the faults which transect the Sinai continental margin extend further northwestward. The Levant Basin is under- lain by an oceanic crust; the adjacent continental margin by a continental crust. It is suggested that at least since the Late Neogene the marine province underwent regional subsidence and the continental province rifting and faulting; the tectonics of the continental margin reflect the superposifion of these two regimes. Dept. of Oceanogr., Texas A&M Univ., College Station, Tex. 77843, USA.


84:5612 Masson, D.G. and P.R. Miles, 1984. Mesozoic

seafloor spreading between Ibetia, Europe and North America. Mar. Geol., 56(1/4):279-287.

A new earliest Cretaceous palaeogeographic reconstruction is proposed to clarify some of the out- standing reconstruction problems in the region. From the time of initial opening to magnetic anomaly 34, the instantaneous motion of Iberia can be described by a single rotation about a pole off the southwest coast of France. In contrast to previous proposals, the new reconstruction places Galicia Bank east of Flemish Cap but satisfies all the constraints imposed by palaeomagnetic studies, DSDP results and magnetic anomaly and ocean- continent boundary identifications. Inst. of Oceanogr. Sci., Brook Rd., Wormley, Godalming, Surrey GU8 5UB, UK.

84:5613 Miall, A.D., 1983. The Nares Strait problem: a

re--evaluation of the geological evidence in terms of a diffuse oblique--slip plate boundary between Greenland and the Canadian Arctic Islands. Tectonophysics, 100(1/3):227-239.

Geophysical models of seafloor spreading in Baffin Bay and the Labrador Sea, which require 200-300 km of sinistral strike-slip motion between Greenland and the Canadian Arctic Islands, are incompatible with the onshore geologic evidence which indicates displacements of less than 50 km across the Nares Strait. This paper attempts to resolve this conflict by distributing the required displacement across a diffuse oblique-slip boundary; however, the detailed palinspastic reconstruction needed to test the presented hypotheses awaits further field work. Dept. of Geol., Univ. of Toronto, Ont. M5S IAI, Canada. (amt)

84:5614 Jolivet, Laurent, Mitsuru Nakagawa, Norio Kito and

J.-P. Cadet, 1984. Early obduction of the Hok- kaldo Ophiolite during the Late Jurassic: foreland and Cretaceous palengeography. C. r. Acad. Sci., Paris, (II)298(10):463-468. (In French, English abstract.) Dept. of Geol. and Mineral., Hok- kaido Univ., Sapporo 060, Japan.

84:5615 Page, B.M. and D.C. Engebretson, 1984. Correlation

between the geologic record and computed plate motions for central California. Tectonics, 3(2): 133-155.

Results of this attempt to 'correlate geological events in part of central California' are mixed. Good

agreement is found between Late Mesozoic history and the reconstructed convergent motion between the Farallon and North American plates. The largest uncertainty concerns the interval 85-43 myBP when it cannot be resolved 'which plate, Kula or Farallon, interacted with the margin of California.' Plate motions also cannot he reconciled with paleomagnetic evidence which indicates 2500 km of coastwise movement of Salinian rocks. Recent Pacific-North American motion correlates well with the geologic record of the last few million years. Dept. of Geol., Stanford Univ., Stanford, Calif. 94305, USA. (amt)

84:5616 Peters, J.M. and S.R. Troelstra, 1984. Early Plioeene

sedimentation in the Cretan region: implications for the timing and mount of vertical motion along the south Hellenic Arc (eastern Mediter- ranean). Mar. Geol., 56(1/4):335-344.

A boxcore from a seamount south of Crete (outer Hellenic Trench) contains allochthonous coarse clastics (fragments of alpine basement, brecciated Early/Middle Pliocene marls and reworked older Neogene sediments) interpreted as an Early/Middle Pliocene mass-flow deposit similar to deposits from adjoining on- and offshore areas. The wide distribution of these sediments may be related to a period of increased tectonic activity which caused substantial vertical movements in the south Hellenic Arc. It is concluded that at the time of the formation of the mass-flow deposits this part of the Hellenic Trench had not yet evolved. Geol. Inst., Univ. van Amsterdam, 1018 VZ Amsterdam, Netherlands.

84:5617 Rehault, J.-P., Gilbert Boillot and Alain Mauffret,

1984. The western Mediterranean Basin geolng- ical evolution. Mar. Geol, 55(3/4):447-477.

The western Mediterranean Sea is explained as a marginal basin, generated by a N-NW subduction of the African-Apulian plates beneath the European plate. Following an Oligocene rifting phase, oceanic accretion occurred between 21 and 18 mya along three main spreading axes trending NE-SW in the Liguro-Proven~al Basin, NW-SE in the southern Sardo-Balearic Basin and E-W in the North Alge- rian Basin. Such kinematics and chronology are consistent with: paleomagnetic data supporting the Sardinian rotation; basin and margin structure; subsidence since 21 m.y., especially during Messi- nian time; and heat-flow measurements. Includes 9 pages of references. Lab. de Geodynam. Sous- Marine, Univ. P. M. Curie, F-06230 Villefranche- sur-Mer, France.


84:5618 Scherrner, E.R., D.G. Howell and D.L. Jones, 1984.

The origin of allochthonons terranes: perspectives on the growth and shaping of continents. A. Rev. Earth planet. Sci., 12:107-131.

The concepts of terrane analysis (Coney et al. 1980); Jones et al. 1983) are summarized and applied to the circum-Pacific region, considered 'a collage of disparate crustal fragments' accreted during the Proterozoic and Phanerozoic by the growth and rifting of crustal blocks along 'tectonically eroded' continental margins. It is concluded that terrane analysis, based upon carefully established genetic relationships of individual terranes, has the potential for refining models of complex, active continental margins. Includes 4 pages of references. USGS, Menlo Park, Calif. 94025, USA. (hbf)

84:5619 von Huene, Roland, 1984. Tectonic processes along

the front of modern convergent margins: research of the past decade. A. Rev. Earth planet. Sci., 12:359-381.

Presented is a historic account of subduction zone research over the past decade. The simple 'bulldozer' model of ten years ago, which was based primarily on single channel seismic reflection data, has developed into a complicated, multi-process model which recognizes the importance of tectonic erosion as well as subduction. Advances in technology, such as multi-channel seismic reflection or multi-beam swath mapping, and the importance of cores, which provide temporal control on the history of tectonic processes, are also discussed. USGS, Menlo Park, Calif. 94025, USA. (amt)

84:5620 Wallace, W.K. and D.C. Engebretson, 1984. Rela-

tionships between plate motions and Late Cre- taceous to Paleogene magmatism in southwestern Alaska. Tectonics, 3(2):295-315. Regional Study Group, ARCO Alaska, Inc., P.O. Box 100360, Anchorage, Alaska 99510, USA.

84:5621 Wells, R.E., D.C. Engebretson, P.D. Snavely Jr. and

R.S. Coe, 1984. Cenozoic plate motions and the volcano-tectonic evolution of western Oregon and Washington. Tectonics, 3(2):275-294.

A 'refined northeast Pacific plate-motion model' is utilized in an analysis of possible origins of the allochthonous Tertiary oceanic basalt basement of the Coast Range. Microplate rotation and accretion are ruled out. Possible scenarios include a modified model hotspot 'in which basalts are episodically

generated along leaky fractures and transforms' or oblique continental rifting leading to basalt eruption as a hotspot was overridden. Also considered are 'possible consequences of an active Yellowstone hotspot' near the Coast Range. USGS, 345 Middle- field Rd., Menlo Park, Calif. 94025, USA. (mjj)

84:5622 Wynne, P.J., E. Irving and K. Osadetz, 1983.

Paleomagnetism of the Esayoo Formation (Per- mian) of northern Ellesmere Island: possible clue to the solution of the Nares Strait dilemma. Tectonophy sics, 100(1/3):241-256.

Paleomagnetic studies of the Esayoo Formation suggest that northern Ellesmere Island has not been displaced latitudinally, but has been rotated anti- clockwise by 36-+8 ° . This suggests that strike-slip motion between Greenland and the Canadian Arctic Islands is distributed over a broad region and helps to resolve the conflict between marine geophysical data that suggest up to 300 km of movement between Greenland and the Canadian Islands, and geological field data that suggest about 50 km of displacement across the Nares Strait. Pacific Geosci. Center, Box 6000, Sidney, B.C. V8L 4B2, Canada. (amt)

84:5623 Ye, Shangfu, 1983. Tectonic characteristics of Taiwan

and its adjacent sea areas. Tropic Oceanol., 2(4):260-268. (In Chinese, English abstract.)

In the early Cenozoic, formation of the marginal seas pushed Taiwan out from the Asian margin as a relict of the continental crust. Late Cenozoic compression collided the arc with the continent; 'the mature evolved continental crust of Taiwan first accreted onto the Asian margin' and comprised the Chinese coastal mountain ranges. The Okinawa Trough is in an early spreading phase; all the marginal seas are typical backarc basins. Dept. of Geol., Nanjing Univ., People's Republic of China. (sir)

D250. Plate and global tectonics

84:5624 Artiushkov, E.V., A.E. Shlezinger and A.L. Ianshin,

1984. Tectonic structures of the World Ocean floor. Dokl. Akad. Nauk SSSR, 275(1): 148-150. (In Russian.)

84:5625 Goguel, Jean, 1983. A short note on continuity or

discontinuity in the global tectonic plate velocities. Tectonophysics, 100(1/3): 1-4.

OLR (1984) 31 (I 1) D. Submarine Geology and Geophysics 803

The various attempts at geodetic measurement of plate motion have been frustrating. Perhaps, by conveniently expressing drift in centimeters/year, we have forgotten that drift is generally episodic. There may be no motion for years, decades, or longer, and then a sudden motion of a few centimeters or meters. 'Without kinetic energy warranting continuity of velocities, only the mean value, taken over a long enough time, has a physical meaning.' 100, Rue du Bac, 75007 Paris, France. (fcs)

84:5626 York, Derek, 1984. Cooling histories from 4°Ar/39Ar

age spectra: implications for Precambrian plate tectonics, A. Rev. Earth planet. Sci~ 12:383-409.

Recent progress in the mapping out of local thermal histories using diffusion-based interpretations of the 4°Ar/39Ar dating method are reviewed. Several types of thermal history are discussed: 'geologically instantaneous' cooling; instantaneous cooling followed by a brief thermal pulse in an otherwise peaceful history; and slow postorogenic cooling. The relevant methods of analysis and interpretation are summarized and examples of each scenario are discussed. The value of 4°Ar/39Ar thermochro- nometry as 'a necessary adjunct of paleomagnetic studies...particularly in the Precambrian' is also discussed. Dept. of Phys., Univ. of Toronto, Ontario M5S 1A7, Canada. (amt)

D280. Volcanism, magmatism

84:5627 Helgason, Johann, 1984. Frequent shifts of the

volcanic zone in Iceland. Geology, geol. Soc. Am., 12(4):212-216.

Frequent shifts of the volcanic zone may account for 'the heterogeneous and locally anomalously thick Icelandic upper crust.' The scale of shifts, the time interval between them, and the intensity of volcanism at each zone have determined the detailed crustal structure. Small-scale shifts occurred about every 2 m.y. and large scale ones every 6 to 8 m.y. Basaltic magma trapped in the upper mantle after shifts of the volcanic zone may contribute to the observed low upper-mantle velocities. Dept. of Geol., Dalhousie Univ., Halifax, N.S. B3H 3J5, Canada. (ecs)

84:5628 Huppert, H.E., R.S.J. Sparks, J.S. Turner and N.T.

Arndt, 1984. Emplacement and cooling of komatiite lavas. Nature, Lond., 309(5963): 19-22.

It is proposed that komatiite lavas were emplaced as turbulent flows, accompanied by vigorous forced convection with cooling rates often in excess of hundreds of C ° h -l. The lavas melted and assimilated up to 10% of the ground over which they flowed, forming deep channels. Nickel sulphide minerali- zation may have resulted from incorporation of sulphur-rich sediment. After emplacement, high cooling rates persisted, resulting in spinifex textures due to compositional convection. Dept. of Appl. Math. and Theoret. Phys., Univ. of Cambridge, Silver St., Cambridge CB3 9EW, UK.

84:5629 Liotard, J.-M. and H.G. Barsczus, 1984. Contri-

bution to the petrography and geochemistry of Elao Island, Marquesas Archipelago, French Polynesia (south central Pacific Ocean). C. r. Acad. Sci., Paris, (II)298(8):347-350. (In French, English abstract.) Lab. de Petrologie, U.S.T.L., place Eugene-Bataillon, 34060 Montpellier Cedex, France.

84:5630 McNutt, S.R. and R.J. Beavan, 1984. Patterns of

earthquakes and the effect of solid earth and ocean load tides at Mount St. Helens prior to the May 18, 1980, eruption. J. geophys. Res., 89(B5): 3075-3086. Lamont-Doherty Geol. Observ., Pal- isades, NY 10964, USA.

84:5631 Mitchell, R.H. and R.G. Platt, 1984. The Freemans

Cove volcanic suite: field relations, petrochem- istry, and tectonic setting of nephelinite-basanite volcanism associated with rifting in the Canadian Arctic Archipelago. Can. J. Earth Sci., 21(4): 428-436. Dept. of Geol., Lakehead Univ., Thun- der Bay, Ont. P7B 5El, Canada.

84:5632 Moorbath, S., R.N. Thompson and E.R. Oxburgh

(eds.), 1984. The relative contributions of mantle, oceanic crust and continental crust to magma genesis. Phil. Trans. R. Soc., (A)310(1514):437- 780; 16 papers.

Seven papers were devoted to a discussion of elemental and isotopic abundances as they bear on the question of magma source. Geophysical and fluid dynamical aspects of magma chambers were considered in 2 papers; crustal contamination of magmatic rocks of different continental regions was the topic of 5 others. The remaining papers addressed petrological constraints on magma sources and crust vs. mantle contributions to island arc magmagenesis. (sir)

804 D. Submar ine Geology and Geophys ics O L R ( 19841 31 ( I I )

84:5633 Notsu, Kenji, Naoki Isshiki and Masataka Hirano,

1983. Comprehensive strontium isotope study of Quaternary volcanic rocks from the Izu-Oga- sawara Arc. Geochem. J., 17(6):289-302. Inst. of Chem., Univ. of Tsukuba, Sakura-mura, Niihari-gun, Ibaraki 305, Japan.

84:5634 Robertson, A.H.F., 1984. Mesozoic deep--water and

Tertiary volcanidastic deposition of Maio, Cape Verde Islands: Implications for Atlantic paleo- envimnmonts and ocean island volcanism. Bull. geol. Soc. Am., 95(41:433-453.

The succession of Late Jurassic-Quaternary rocks exposed on this eastern central Atlantic island reveals its Late Jurassic and Early Cretaceous genesis at a spreading axis followed by deep-ocean sedimentation, uplift, volcanism, deformation, plutonism, Neogene and Quaternary volcanism, and more recent uplift and peneplanation. The Maio sequences are compared with DSDP and Senegal Basin core data and available seismic and gravity data. The interpretations have significance for an understanding of Atlantic Mesozoic paleoenviron- merits and Tertiary island-building and hotspot activity. Grant Inst. of Geol., West Mains Rd., Edinburgh EH9 3YW, Scotland. (hbf)

84:5635 Siegel, S.M. and B.Z. Siegel, 1984. First estimate of

• nnqal mercury flux at the Kilauea main vent. Nature, Lond., 309(5964):146-147.

From 1971 to 1980, Hg and SO 2 analyses were carried out on air samples collected immediately downwind of Halemanmau, the Kilauea main vent. A Hg/SO2 ratio of 0.51 × 10 -3 was derived and applied to the recently determined SO2 mass output of Halemaumau yielding a calculated Hg flux of 2.6 × 10 s g annually. This value is consistent with recent evidence suggesting that volcanogenic Hg contributes significantly to the atmospheric total. Dept. of Botany, Univ. of Hawaii, Honolulu, Hawaii 96822, USA.

84:5636 Simkin, Tom and R.S. Fiske, 1983. Krakatau 1583:

the vo/cank empaon and its effects. Smithsonian Institution Press, Washington, D.C.; 464pp. $25.00 cloth, $15.00 paper

A century after the eruption of Krakatau in the Dutch East Indies resulted in the death of 36,417 people and the destruction of 165 villages, a new compilation of 88 eyewitness accounts and selected scientific papers provides a fresh view of history's

most famous eruption and its 'extraordinary impact on the atmosphere and oceans.' Verbeek's 1885 official report, translated into English for the first time, is included. Scientific accounts describe and attempt to explain not only the geological phenomena, but also air and sea waves, atmospheric effects (sunsets, blue/green suns, Bishop's rings), climatic effects, and the return of life to the 'new' islands. The volume contains an index, a 16-page bibliography, several color plates, and numerous drawings. (hbf)

84:5637 Simkin, Tom, Lee Siebert, Lindsay McCleUand,

David Bridge, Christopher Newhall and J.H. Latter, 1981. Volcanoes of the worM. A regional directory, gazetteer, and chronology of volcanism during the last 10,000 years. Hutchinson Ross Publishing Company, Stroudsburg, Penn- sylvania; 233pp.

This comprehensive directory of the world's 1343 known volcanoes represents 10 years of systematic data collection and collation. It is thought to be the first cross-referenced gazetteer of volcano names and the first such single volume in English in the last 100 years. Data provided on individual volcanoes include name, geographic location, elevation, morphologic type, number, and status. Data dealing with eruptions treat area and duration of activity, dating techniques, eruptive characteristics, volcanic ex- plosivity index, and volume of products. The records amassed suggest that volcanism is episodic and that within the past 600 years there has been an exponential increase in the number of known active volcanoes. (Contemporary information on global volcanic activity can be found in the Smithsonian Institution's SEAN Bulletin.) (hbf)

84:5638 Stern, R.J. and L.D. Bibee, 1984. Esmeralda Bank:

geochemistry of an active submarine volcano in the Marinna Island Arc. Contr. Miner. Petrology, 86(2): 159-169.

Esmeralda Bank volcanics differ from other Mariana Arc lavas in Ti and Fe abundance (higher), A1 (lower), and Ti-Zr plots. No appreciable contribution of subducted material (neither sediments nor MORB) is evident. Geochemical analyses suggest an ocean-island type mantle source located in the upper 60-110 km. Such a source location 'places a new and significant constraint' on upper mantle layering and evolution. Program in Geosci., Univ. of Texas, Box 830688, Richardson, Tex. 75083-0688, USA. (sir)

OLR 0984) 31 (I I) D. Submarine Geology and Geophysics 805

84:5639 Vinci, A., 1984. Chemical differences between the

island and submarine pumice layers of Tbera. Mar. Geol., 55(3/4):487-491.

Investigations of tephra layers in deep-sea cores near the island of Santorini showed that only the pumice clasts from the western part of the island can be attributed to the Minoan eruption. The tephra layers within the caldera are of uncertain origin. Inst. of Petrography, Univ. of Parma, I-Parma, Italy.

84:5640 Wright, T.L., 1984. Origin of Hawaiian tholeflte: a

metasomatic model. J. geophys. Res., 89(B5): 3233-3252.

Least squares petrologic mixing calculations indicate that differences in the chemistry of mid-ocean ridge tholeiite (MORB) and Hawaiian tholeiite (HT) can be explained by metasomatic processes within the uppermost mantle. Extensive studies of Kilauea Volcano have provided constraints on the processes of partial melting and magma collection beneath Hawaii. Melting to produce Kilauean magma (MORB) apparently takes place within partially melted mantle; HT is produced when MORB is metasomatized by fluids derived from deeper in the mantle. Includes 4 pages of references. USGS, 959 National Center, Reston, Va. 22092, USA. (ecs)

D290. Crust, mantle, core

84:5641 Acharya, Hemendra, 1984. Seismicity chan~es prior

to several great earthquakes [M~_- 8.0l in the ~ P a c i f l c area. Bull. seism. Soc. Am., 74(3): 943-955.

Strain energy released in the rupture zone of several post-1950 great earthquakes was computed for every year between 1910 and the time of the earthquake. Examination shows that maximum strain energy is released in the rupture zone at a time which depends on the magnitude of the subsequent great earthquake. The ratio of strain energy released in the earthquake to the maximum strain energy varies between 3 and 30, i.e., this burst of activity is equivalent to a single earthquake of magnitude 0.5-2 units less than the magnitude of the great earthquake. The amount of maximum deformation and the time at which it occurs appear to depend on the magnitude of the great earthquake. Stone and Webster Engng. Corp., 245 Summer St., Boston, Mass. 02110, USA.

84:5642 Angevine, C.L. and D.L. Turcotte, 1983. Correlation

of geoid and depth anomalies over the Aguihas Plateau. Tectonophysics, 100(1/3):43-52.

The plateau is compensated in part by crustal thickening and in part by an underlying layer of anomalously low density mantle extending to a depth of about 50 km (density 1-2% lower than normal). Crustal thickening alone is insufficient to explain the observed correlation between bathymetry and the geoid. The anomalous mantle region may be the source for the excessive volumes of basalt which have intruded and thickened the crust of the plateau; there is strong evidence that depleted mantle rock is lighter than undepleted mantle rock. Dept. of Geol. Sci., CorneU Univ., Ithaca, NY 14853, USA.

84:5643 Batiza, Rodey, 1984. Inverse relationship between Sr

isotope diversity and rate of oceanic volcanism has implications for mantle heterogeneity. Nature, Lond~ 309(5967):440-441.

Comparison of the average spreading rate of nine portions of the mid-ocean ridge system with the measured STSr/S6Sr diversity of basalts shows that the maximum observed Sr diversity is inversely propor- tional to spreading rate. Furthermore, globally averaged eruption rates for mantle-derived oceanic rocks exhibit a negative correlation with 87Sr/StSr diversity. These results suggest that the upper mantle is everywhere heterogeneous on a small scale and that the extent of observed heterogeneity is a function of mixing (mixing is enhanced by the presence of a magma chamber). Mixing during melt production, segregation or ascent could result in the observed patterns if the degree of mixing is related to eruption rate. Large heterogeneities (mantle plumes?) are required to explain why isotopic variations are well correlated geographically in some places but not in others. Dept. of Earth and Planet. Sci., Washington Univ., St. Louis, Me. 63130, USA.

84:5644 Buck, W.R. and M.N. Toks0z, 1983. Thermal effects

of continental collisions: thickening a variable viscosity lithosphere. Tectonophy sics, 100(1/3): 53-69.

Numerical experiments were conducted to test whether the high heat flux observed in regions of thickened crust associated with convergence zones (most notably Tibet) could be attributed to convective removal of thermal boundary layers thickened by convergence. Unlike previous models, viscosity was a function of temperature and pressure and the

806 D. Submarine Geology and Geophysics OLR (1984}31 (1 I)

lithosphere-asthenosphere boundary was calculated rather than specified. The time scale for convective thinning was greater than 100 m.y. for initial lithospheric thicknesses of 100 km indicating that the lithosphere must therefore be very hot and thin (due, for example, to subduction-induced convection) before extensive melting of the thickened lower crust can occur. Dept. of Earth, Atmos. and Planet. Sci., MIT, Cambridge, Mass. 02139, USA. (amt)

84:5645 Cockerham, R.S., 1984. Evidence for a 180-kin-long

subducted slab beneath [Cape Mendocino in] northern California. Bull. seism. Soc. Am., 74(2): 569-576.

The inclined seismic zone dips ~ 1 0 to 11 ° in the direction $68°E for 120 km to depths of 30 to 35 km, then steepens to 25 ° and plunges to depths of at least 60 km. P-wave focal mechanisms of 2 earthquakes at depths of 30 and 58 km are consistent with downdip tension and imply that these events resulted from stresses within the slab and not from Gorda- North American plate interaction. USGS, 345 Middlefield Rd., Menlo Park, Calif. 94025, USA.

84:5646 Cogley, J.G., 1984. Continental margins and the

extent and number of the continents. Revs Geophys. Space Phys., 22(2): 101-122.

When the area of continental crust submerged beneath the oceans is considered, 14 continents covering 41% of the earth's surface are identified. Thus the continents are 'more extensive and less dispersed than conventionally thought.' Continental height and thickness are found to be related; small continents are thinner than large continents. The average thickness is 36 km and the average height is 120 m. This study was based on an extensive search of the geologic and geophysical literature through 1982. Includes ca. 225 references. Dept. of Geogr., Trent Univ., Peterborough, Ontario K9J 7B8, Can- ada. (amt)

84:5647 Coudert, Ehsabeth, R.K. Cardwell, B.L. Isacks and

J.-L. Chatelain, 1984. P-wave velocity of the uppermost mantle and crustal thickness in the central Vanuatu Islands (New Hebrides Island Arc). Bull. seism. Soc. Am., 74(3):913-924.

Two different methods and data sets were used; both methods yielded a mantle velocity of 7.6 (_+0.1) km/sec and a crustal thickness of 27 (+-2) km just trenchward of the volcanic arc. Published refraction studies have demonstrated that the mantle velocity

near the trench has a more typical value of 8.0 km/sec. This contrast in mantle velocities between the trench and the volcanic arc has also been reported for the Japanese and Kurile-Kamchatka island arcs and, therefore, may be a general feature of subduction zones. Dept. of Geol. Sci., Cornell Univ., Ithaca, NY 14853, USA.

84:5648 Creager, K.C. and T.H. Jordan, 1984. Slab pene-

tration into the lower mantle. J. geophys. Res., 89(B5): 3031-3049.

P and PKIKP travel times from 14 intermediate and deep focus earthquakes from subduction zones in the northwestern Pacific are analyzed to obtain an estimate of lateral velocity heterogeneity in the near source region. The objective of this study is to determine whether the downgoing slab penetrates the velocity anomaly at 650 km depth. In contrast to the results of a recent, similar study beneath Tonga, the authors conclude that the data require that the slab penetrate to at least 900-1000 km beneath the Sea of Okhotsk. This result has important implications for models of convective and chemical stratification of the mantle. Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA. (amt)

84:5649 Fox, P.J. and D.G. Gallo, 1984. A tectonic model for

ridge-transform-ridge plate boundaries: implications for the structure of oceanic lithosphere. Tectonophysics, 104(3/4):205-242.

A model of ridge-transform-ridge plate boundaries is presented in which a 'weld of upper mantle material creates a shear couple in the lithosphere.' The morphotectonic character of the transform is then a function of the age contrast across the transform. Geologic and geophysical data from a number of transforms are reviewed in light of this model. Includes 5 pages of references. Grad. Sch. of Oceanogr., Univ. of Rhode Island, Narragansett, RI 02882, USA. (amt)

84:5650 Horn, J.R., R.M. Clowes, R.M. Ellis and D.N. Bird,

1984. The seismic structure across an active oceanic/continental transform fault zone. J. geophys. Res., 89(B5):3107-3120.

An offshore-onshore refraction experiment was used to determine the seismic structure across the southern Queen Charlotte transform fault zone. Three distinctive crustal blocks--oceanic, terrace, and continental--were identified; the blocks are separated by the crustally pervasive outer and inner Queen Charlotte faults. The results agree with the


observed gravity anomaly and with tectonic models that require a convergence component along the fault zone. Dept. of Geophys. and Astron., Univ. of British Columbia, Vancouver, B.C. V6T lW5, Can- ada. (msg)

84:5651 Ida, Yoshiaki, 1984. Stress and relaxation time in the

viscoelastic Hthosphere inferred from the outer topographic rise. J. geophys. Res., 89(B5):3211- 3221.

A simple treatment applicable to an arbitrary value of Poisson's ratio introduces a new variable that represents the pressure gradient from plate top to bottom. 1-D stationary deformation of the moving plate is given by a simple analytic equation used to analyze the bathymetry of the outer rise seaward of trenches. Lithosphere in western Pacific trenches is subject to an extensional force of > 100 MPa; this may be much less or even compressive in eastern Pacific trenches. To prevent horizontal force and bending stress from being extraordinarily large, the Maxwell relaxation time of the plate must be < 1 m.y. and the effective viscosity l024 Pa s or less. Ocean Res. Inst., Univ. of Tokyo, 1-15-1, Minami- dai, Nakano-ku, Tokyo 164, Japan.

84:5652 International Crustal Research Drilling Group,

1984. Are Troodos deposits an East Pacific analog? Geotimes, 29(5): 12-14.

Composition of the massive sulfide deposits at Agrokipia, Cyprus, was investigated as part of a study of Troodos ophiolite. Two holes, one to 689 m, were drilled through the sulfides into the underlying stockwork zones (hydrothermal channels). Troodos sulfides appear similar to those of the EPR. They apparently formed during crustal construction; the mineralizing fluid was modified seawater near 350°C. The sulfide deposits are characterized by 'areally limited gravity highs and magnetic lows' which may be hard to resolve and interpret even from surveys close to the sea bottom. Geol. Survey Dept., Nicosia, Cyprus. (ecs)

84:5653 Kim, Won-Young, Ota Kulhfinek and Klaus Meyer,

1984. Source processes of the 1981 Gulf of Corinth earthquake sequence from body-wave analysis. Bull. seism. Soc. Am., 74(2):459-477. Seismol. Dept., Uppsala Univ., Box 120 19, 750 12 Uppsala, Sweden.

84:5654 Le Douaran, Sylvie, Jean Burrus and Felix Avedik,

1984. Deep structure of the northwestern Medi-

terranean basin: results of a two-ship seismic survey. Mar. Geol., 55(3/4):325-345.

In the Gulf of Lions and the Ligurian Sea, 3 geological domains are distinguished: thick continental (crust >20 km, velocity 6.2 kin/s), thinned continental (crust 5-7 km), and oceanic (crust 5 kin, but double-layered; velocities 5.8 and 6.9 kin/s). The thinned continental domain is very wide (100 km) in the Gulf of Lions and considerably reduced in the Ligurian Sea. The two basins are separated by a major fracture zone. Elf Aquitaine, Tour Generale, 92088 Paris La Defense, France.

84:5665 Lin, Jinfeng, 1983. Features of crustal structure and

the upper mantle in the central South China Sea as inferred from gravity anomalies. Nanhai Stud. mar. sin., 4:1-9. (In Chinese, English abstract.) South China Sea Inst. of Oceanol., Acad. Sin., People's Republic of China.

84:5656 Lister, G.S., Greetje Banga and Anne Feenstra,

1984. Metamorphic core complexes of Cordilleran type in the Cyclades, Aegean Sea, Greece. Geology, geol. Soc. Am., 12(4):221-225. Inst. for Earth Sci., Univ. of Utrecht, 3508 TA Utrecht, Netherlands.

84:5657 Lobkovskii, L.I. and B.V. Baranov, 1984. A key

model of strong earthquakes in island arcs and active continental marginal zones. Dokl. Akad. Nauk SSSR, 275(4):843-847. (In Russian.)

g4:5658 Makris, Jannis and C. Stobbe, 1984. Physical

properties and state of the crust and upper mantle of the eastern Mediterranean Sea deduced from geophysical data. Mar. Geol., 55(3/4):347-363.

Oceanic-type crust floors the Ionian Abyssal plain (14 km thick, sediments 8 km thick) and the Herodotus Abyssal Plain (22 km thick, sediments 10-15 km thick). The Eastern Mediterranean Rise, of disputed affinity, has crust ranging 28-34 km and sediments 10 km thick. The eastern Mediterranean's borders are thick continental crust; the northern border is a tectonically active margin defined by the Calabrian, Hellenic and Cyprus-Antalya arcs, whereas the southern margin is passive. This margin and the deep basins are controlled mainly by subsidence and stretching. Inst. of Geophys., Univ. of Hamburg, Bundesstrasse 55, D-2000 Hamburg 13, FRG.

808 D. Submarine Geology and Geophysics OLR (1984) 31 I 111

84:5659 McAdoo, D.C. and C.F. Martin, 1984. Seasat

observations of Ilthosphefic flexure seaward of trenches. J. geophys. Res., 89(B5):3201-3210.

A simple elastic model for the oceanic lithosphere yields estimates of model parameters from altimeter data. Effective lithospheric thicknesses are calculated for the Mariana, Kuril, Philippine, Aleutian, Izu-Bonin, and Middle America outer rises. Results support the proposition that effective thickness increases with age of lithosphere. Close agreement with the thickness/age relation suggests that there is no need to assume significant horizontal compression across the Kuril, Marianas, and Izu-Bonin trenches. This thickness/age relation implies that flexural strength of the oceanic lithosphere is temperature controlled. NOAA/NOS, Natl. Geo- detic Survey, RockviUe, Md. 20852, USA.

84:5660 Nakanishi, Ichiro and Hiroo Kanamori, 1984.

Source mechanisms of twenty-six large, shallow earthquakes (M s >__ 6.5) during 1980 from P-wave first motion and long-period Rayleigh wave data. Bull. seism. Soc. Am., 74(3):805-818. Res. Center for Earthquake Prediction, Hokkaido Univ., Sapporo 060, Japan,

84:5661 P~rez, O.J. and C.H. Scholz, 1984. Heterogeneities of

the instrumental seisinicity catalog (1904-1980) for strong shallow earthquakes. Bull. seism. Soc. Am., 74(2):669-686. FUNVISIS Apt. 1892, Ca- racas 1010, Venezuela.

84:5662 Prothero, W.A. Jr. and William Schaecher, 1984.

First noise and teleseismie recordings on a new ocean bottom seismometer capsule. Bull. seism. Soc. Am., 74(3): 1043-1058.

An OBS capsule designed specifically for the long-term (1 yr) monitoring of teleseisms has been designed and tested. An efficient triggering algorithm consisting of multiple high-pass filters effec- tively discriminates between locally generated earthquakes and noise, and teleseisms. Data are recorded on two Braemar cassette recorders with a capacity of 15 Mbits each, for a continuous recording time of approximately 43 hr. This is adequate for the expected data acquisition rate, given the robustness of the triggering algorithm. Dept. of Geol. Sci. Univ. of Calif., Santa Barbara, Calif. 93106, USA.

84:5663 Recq, Maurice, J.-P. Rehault, Leon Steinmetz and

A. Fabbri, 1984. Crustal thinning and oceanic

accretion in the central Tyrrhenian Basin from seismic refraction data. Mar. Geol., 55(3/4):411- 428. (In French, English summary.)

Inferred P-wave velocity depth distributions are similar to those computed for oceanic spreading zones. Velocity inversions within the crust, Moho depth at 10-11 km and low Pn velocity suggest the existence of abnormal mantle. Along 40°N from the Sardinian to Apenninic margins, the Moho rises from 27 km to 11 km beneath the central Tyrrhenian Basin. Data support the assumption of recent accretion beneath the central basin. Lab. de Geol. Dynam., Univ. P. & M. Curie, 4 Place Jussieu, 75230 Paris Cedex 05, France.

84:5664 Rehault, J.-P. and Nicole Bethoux, 1984. Earthquake

relocation in the Ligurian Sea (western Medi- terranean): geological interpretation. Mar. Geol., 55(3/4):429-445.

Relocated epicenters are computed with a model based on complex local structure, i.e. oceanic floor in the central Ligurian Basin and thinned continental margins. By superposing these relocated earthquakes on a basement bathymetric map, the structural relations are clearly demonstrated. Com- pressive stress trending W-NW is confirmed in the northern Ligurian Basin by focal mechanism study. Most of the earthquakes appear to be shallow and linked to rejuvenation of older distensive and strike-slip structures on margins as in the basin by a compressional motion. Univ. P. et M. Curie, Lab. de Geodynam. Sous-Marine, B.P. 48, 06230 Ville- franche-sur-Mer, France.

84:5665 Thatcher, Wayne, 1984. The earthquake deformation

cycle at the Nankai Trough, southwest Japan. J. geophys. Res., 89(B5):3087-3101.

The process of strain buildup during a complete earthquake cycle is studied by examining geodetic measurements landward of the Nankai Trough where leveling data are available from 1890 and large earthquakes occurred in 1854 and 1946. The data indicate that 'postseismic deformation extends more than 300 km inland from the plate boundary, persists for at least 30 years, and shows a clear tendency to become longer wavelength with increasing time.' Due to nonlinearity of the strain buildup and permanent ground deformation, simple recur- rence rate calculations may be overestimated by a factor of 2-3. USGS, 345 Middlefield Rd., MS/77, Menlo Park, Calif. 94025, USA. (amt)

OLR 0984) 31 (! l) D. Submarine Geology and Geophysics 809

84:5666 Tryggvason, Kristjan, E.S. Husebye and Ragnar

Stef~nsson, 1983. Seismic image of the hypoth- esized Icelandic hot spot. Tectonophysics, 100(1/3):97-118. NTNF/NORSAR, Box 51, 2007 Kjeller, Norway.

84:5667 Wesnousky, S.G., C.H. Scholz, K. Shimazaki and T.

Matsuda, 1984. Integration of geological and seismological data for the analysis of seismic hazard: a case study of Japan. Bull. seism. Soc. Am., 74(2):687-708.

This paper represents an attempt to overcome two deficiencies inherent in conventional methods of seismic hazard analysis, i.e. 'the uncertainty involved in estimating long-term average rates of seismicity' from short historical records and the 'failure to accurately consider the time-dependent nature of the earthquake rupture process.' Quaternary fault data and time dependence are incorporated into a quantitative evaluation of seismic hazard. The method is applied to Japan, where a 400-year-long record of seismicity is available; both the spatial and size distribution of events can be predicted from the geologic record of Quaternary faults. Results are displayed as a series of maps of instantaneous seismic hazard. Seismol. Lab., Calif. Inst. of Tech., Pasadena, Calif. 91125, USA. (amt)

84:5668 Wong, How Kin and E.T. Degens, 1984. The crust

beneath the Red Sea-Gulf of Aden-East Mrtcan Rift System: a review. Mitt. geol.-pall~ont. Inst. Univ. Hamb, 56:53-94.

The geology, geophysics and plate tectonics of the Red Sea and Gulf of Aden, where active seafloor spreading is occurring, are reviewed, and the seismicity, structure, and gravity of the East African Rift System, which is generally believed to be an example of early continental rifting, are described. Remarks on the structural evolution of these areas are included. Includes 6 pages of references. Palaontol. Inst. und Mus. der Univ., Hamburg, Bundestrasse 55, D-2000 Hamburg 13, FRG. (hbf)

D330. Oil and gas

84:5669 Cook, R.A. and F.J. Davey, 1984. Hydrocarbon

exploration of the basins of the Ross Sea, Antarctica, from modellin~ of the geophysical data. J. Petrol. Geol~ 7(2):213-225. New Zealand

Geol. Survey, DSIR, PO Box 30-368, Lower Hutt, New Zealand.

84:5670 Issler, D.R., 1984. Calculation of organic maturation

levels for offshore eastern Canada: implications for general application of Lopatin's method. Can. J. Earth Sci., 21(4):477-488. Dept. of Oceanogr., Dalhousie Univ., Halifax, N.S. B3H 4J1, Can- ada.

D340. Manganese nodules, etc.

84:5671 Dymond, Jack et al., 1984. Ferromanganese nodules

from MANOP sites H, S, and R: control of mineralogical and chemical composition by multiple ~ o n a r y processes. Geochim. cosmochim. Acta, 48(5):931-949.

Three accretionary processes can account in a qualitative way for the chemical composition of nodules from the three sites. Direct precipitation of colloidal metal oxides from seawater and accretion by oxie diagenesis in the sediment column appear to occur at all three sites; suboxic diagenesis occurs only at the hemipelagic site H. 'The single controlling variable for establishing the sedimentary environment favorable to...nodule accretion_As the flux of biogenic matter.' Sch. of Oceanogr., Oregon State Univ., Corvallis, Oreg. 97331, USA. (ecs)

84:5672 Emerson, Steven et al., 1984. The manganese nodule

program (MANOP). (Special section.) Geochim. cosmochim. Acta, 48(5):895-992; 9 papers.

The Manganese Nodule Project, as a large group effort, completed its work at the end of 1983, bequeathing to the 'geochemical/oceanographic community...a major new analytical facility that is...beginning to return scientific information and an unsurpassed geochemical knowledge about four locations on the ocean floor.' Presented here are the results of recent MANOP investigations. Topics include: the oxidation state of Mn in surface sediments; nodule growth rates at MANOP Site H; control of ferromanganese composition by multiple accretionary processes; radiochemical observations on Mn nodules; trace metal adsorption by interfacial sediment; transition metal remobilization and 02 consumption rates in surficial pelagic sediments; and a status report on the fate of organic carbon on the seafloor. (msg)

810 D Submar ine Geology and Geophys ics O L R ( 1984131 I I 11

84:5673 Finney, Bruce, G.R. Heath and Mitchell Lyle, 1984.

Growth rates of manganese-rich nodules at MANOP Site H (eastern North Pacific). Geochim. cosmochim. Acta, 48(5):911-919.

Probable growth rates of ferromanganese nodules are 30-300 mm/m.y., much faster than most pelagic nodules. A typical nodule consists of two composi- tionally distinct nondetrital components, one rich in Mn, U and Sb, and the other in Fe, Co, REE, Ni, Cu and Th. The component enriched in Mn, which is most abundant on nodule bottoms, appears to accrete much faster (200 mm/m.y.) than the component enriched in Fe (55 mm/m.y.). Coll. of Oceanogr., Oregon State Univ., Corvallis, Oreg. 97331, USA.

84:5674 Halbach, P. and D. Puteanus, 1984. The influence of

the carbonate dissolution rate on the growth and composition of Co-rich ferromanganese crusts from central Pacific seamount areas. Earth planet. Sci. Letts, 68(1):73-87.

The metal composition of ferromanganese crusts in Line Islands chain and Mid-Pacific Mountains seamount samples shows a clear relationship to bottom morphology, water depth, and age. As a result of metal determinations and dissolution experiments on carbonate plankton samples, a model is proposed that suggests that the rate of carbonate dissolution in the water column probably controls the metal composition and growth rates of hydrogenetic ferromanganese precipitates. The growth periods and variations in the crusts are related to changing paleoceanographic parameters. Inst. fur Mineralogie und Mineralische Rohstoffe, D-3392 Clausthal Zellerfeld, FRG. (hbf)

84:5675 Huh, Chih-An and Teh-Lung Ku, 1984. Radio-

chemical observations on manganese nodules from three sedimentary environments in the North Pacific. Geochim. cosmochim. Acta, 48(5): 951-963. WHOI, Woods Hole, Mass. 02543, USA.

84:5676 Inoue, Teruo, Zui-Yao Huang, Mineo Imamura,

Shigeo Tanaka and Akira Usui, 1983. ~°Be and ~°Be/gBe in mangtmese nodnies. Note. Geochem. J., 17(6):307-312. Inst. for Nuclear Study, Univ. of Tokyo, Tanashi, Tokyo 188, Japan.

84:5677 Moore, W.S., 1984. Thorium and radium isotopic

relationships in manganese nodules and sediments

at MANOP Site S. Geochim. cosmochim. Acta, 48(5):987-992. Dept. of Geol., Univ. of South Carolina, Columbia, SC 29208, USA.

84:5678 Poppe, L.J., R.F. Commeau, J.A. Commeau, F.T.

Manheim and P.J. Aruscavage, 1984. Ferro- manganese mieronodnies from the surfidal sod- iments of Georges Bank. J. mar. Res., 42(2):463- 472. USGS, Woods Hole, Mass. 02543, USA.

D360. Books, collections (general)

84:5679 DeFigueiredo, R.J.P. and G.H.F. Gardner (eds.),

1984. Oceanic seismic exploration. Special issue. IEEE Jl ocean. Engng, OE-9(1):1-52; 7 papers.

New techniques and technologies devised to probe the ocean bottom and subbottom by means of acoustic signals are described in a series of invited papers. Among the topics: the problem of forward modelling and the relative merits of numerical and physical modelling; methods for the inversion of acoustic field data and for obtaining sound speed and sound-speed gradients; analysis and measurement of data from towed arrays; and characterization of seafloor roughness. (hbf)

84:5680 Degens, E.T., Wolfgang Krumbein and Alexander

Prashnowsky (eds.), 1984. [A north-south profile: central Europe--Mediterranean-Mrica.] Festband Georg Knetsch. Mitt. geol.-paldont. Inst, Univ. Hamb., 56:461pp; 27 papers. (German with some English.)

84:5681 Friedman, M. and M.N. ToksOz (eds.), 1983.

Continental tectonics: structure, kinematics and dynamics. Special issue. Tectonophysics, 100(l/3):480pp; 24 papers.

A collection of invited papers, ranging in scope and scale from continental plates to the individual crystal, is presented in celebration of the 100th volume of Tectonophysics, first published in 1964. The first portion of the issue treating continental tectonic phenomena--plate velocities, continental collision, crustal subsidence, geoid and depth anomalies, and hotspots--is followed by discussions of structure, kinematics, and dynamics of the various plates and plate boundaries. The final group of papers deals with stress, strain, and microcracks. 01bf)

OLR (1984) 31 (I 1) 811

84:5682 Morelli, C. (ed.), 1984. Geological and geodynamical

aspects of the Mediterranean. (Meeting, 2-11 December 1982, Monaco.) Special issue. Mar. Geol., 55(3/4):163-491; 17 papers.

Included here are papers presented at a meeting of the Committee for Marine Geology and Geophysics of the International Commissions for the Scientific Study of the Mediterranean Sea. Major topics included slumping and faulting, crust and mantle of the eastern Mediterranean, evolution of the western basin, deep structure of the northwestern basin, and tectonics of the southeastern continental margin. Additional topics included geological and geophysical descriptions of specific segments such as the Tyrrhenian Sea, the Rhrne deep-sea fan, the Cala- brian Arc and Ionian Sea, the Provenqal,Basin, the Ligurian Sea, the Sicilian Channel, and various islands. (hbf)

D370. Miscellaneous

84:5683 Deep Sea Drilling Project (Leg 95 scientific party),

1984. New Jersey Transect. DSDP Leg 95 adds data on the Atlantic margin. Geotimes, 29(5): 14- 16.

The transect extends from the New Jersey coastal plain to the continental rise across an area where there is an extensive data base and detailed offshore seismostratigraphic profiles. At Site 612, 5 lithologic units and 7 unconformable sequence boundaries were penetrated; at Site 613, 3 distinct lithologic

units with 3 unconformable contacts were encountered. A 25-37 m.y. Late Miocene to Middle Eocene-Early Oligocene hiatus was documented at both sites. Scripps Inst. of Oceanogr., La Jolla, Calif. 92093, USA. (hbf)

84:5684 Newson, H.E., 1984. The lunar core and the origin of

the Moon. Eos, 65(22):369-370.

The observed depletion of siderophile elements in lunar samples suggests the existence of a metal core. The amount of metal in the core depends on the conditions under which metal segregation occurred. If the Moon accreted directly from the solar nebula, with chondritic abundances of siderophile elements, then 2% to 5.5% metal must have segregated within the Moon to form a core. If the Moon formed from material out of the Earth's mantle, less metal need be segregated because the mantle was already partially depleted in siderophile elements due to formation of the Earth's core. The siderophile elements therefore provide strong geochemical evidence for a lunar metal core but do not rule out either formation of the Moon from the Earth's mantle or by accretion from the solar nebula. Max-Planck-Inst. fur Chem., Abteilung Kosmochemie, Saarstrasse 23, D-6500 Mainz, FRG.

84:5685 Rasmussen, K.L., H.B. Clausen and T. Risbo, 1984.

Nitrate in the Greenland Ice Sheet [not anomalous] in the years following the 1908 Tunguska event. Icarus, 58(1):101-108. Inst. of Geophys. and Planet. Phys., Univ. of Calif., Los Angeles, Calif. 90024, USA.

E. BIOLOGICAL OCEANOGRAPHY

El0. Apparatus and methods

84:5686 Davies, J.M. and P.J. leB. Williams, 1984, Verifi-

cation of |4C and Oz derived primary organic production measurements using an enclosed ecosystem. J. Plankt. Res., 6(3):457-474.

No effect of containment on photosynthesis could be found; rates of 02 change in-vitro (bottles) agreed with rates in-situ (enclosed natural water column). Therefore the ~4C-method was tested in-vitro by comparing 14CO2 uptake with O2 evolution; the two methods agreed. The results suggest that the t4C- method provides a valid measurement of primary production in coastal waters. Sources of error in the

submarine geology and geophysics

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