knowledge of antarctic geology. Folio 12 of the Ant-arctic Map Folio Series has now been published by theAmerican Geographical Society with support from theNational Science Foundation (Bushnell and Grad-dock, 1970). It can be obtained for $12 from theAmerican Geographical Society, Broadway at 156thStreet, New York, New York 10032. The folio con-tains (1) 18 regional geologic maps at a scale of1:1,000,000 or larger, (2) maps of the entire conti-nent at a smaller scale portraying geology, tectonics,fossil and age determination localities, and geo-morphic features, and (3) a map of Gondwanaland.The completion of Folio 12 made possible a new in-terpretation of the tectonics of Antarctica (Craddock,1970a) and new insight into the place of Antarctica inthe former protocontinent Gondwanaland (Craddock,1970b).

There long has been a need for a geologic map ofAntarctica at a scale of 1:5,000,000 (a standard scalein general usage elsewhere) to facilitate comparisonsbetween the continents. Although they were publishedat a smaller scale, the maps of the entire continent inFolio 12 were compiled on the scale of 1:5,000,000 toallow the subsequent preparation of such a map bycombining the data on the individual maps. A greatdeal of new information on antarctic geology hasbecome available during the past year, especially atthe 1970 Oslo symposium, and I have revised the mapto include, wherever feasible, all new data available tome in May 1971. The finished map will include geo-logic units, structural data, fossil and age determina-tion localities, bathymetric and ice-cap surface con-tours, and references to new sources beyond thosecited in Folio 12. This map is now in the final draft-ing stage and should be published shortly.

In my role as a member of the Committee on PolarResearch and U.S. member of the Scientific Commit-tee on Antarctic Research Working Group on Geol-ogy, during the past year I have (1) assisted in prepa-ration for the SCAR/ International Union of Geologi-cal Sciences symposium on antarctic geology andsolid-earth geophysics held in Oslo in August 1970, (2)prepared a review of the events of that symposium(Craddock, 1970c), (3) organized and chaired a sym-posium on antarctic geology at the 1970 annual meet-ing of the Geological Society of America in Milwau-kee, (4) supervised the preparation of an annual re-port to SCAR on USARP earth sciences activities(Craddock, 1970d), and (5) initiated the compilationof a lexicon of stratigraphic names introduced bymembers of U.S. antarctic expeditions.

References

Bushnell, V. C., and C. Craddock (eds.). 1970. Geologicmaps of Antarctica. Antarctic Map Folio Series, 12.

Craddock, C. 1970a. Antarctic tectonics. Geological So-ciety of America. Abstracts with Programs, 2(7): 527. Inpress, Oslo, Universitetsforlaget.

Craddock, C. 1970b. Antarctic geology and Gondwana-land. Bulletin of the Atomic Scientists, 26(10): 33-39.

Craddock, C. 1970c. Antarctic geology in Oslo. Geotimes,15(9): 20-22.

Craddock, C. (ed.). 1970d. Earth Sciences Investigationsin the U.S. Antarctic Research Program for the PeriodJuly 1, 1969, to June 30, 1970. National Academy of Sci-ences. 31 p.

Rutford, R. H., C. Craddock, R. L. Armstrong, and C. M.White. 1970. Tertiary glaciation in the Jones Moun-tains, Antarctica. Geological Society of America. Abstractswith Programs, 2(7) : 670-671. In press, Oslo, Univek-sitetsforlaget.

Mummified sealsof southern Victoria Land

WAKEFIELD DORT, JR.

Department of GeologyThe University of Kansas

One of the more puzzling of the many interestingfeatures of the dry valleys of southern Victoria Landis the presence there of numerous seal bodies well pre-served by desiccation or mummification in the cold,dry environment (see cover). These unusual remainswere first discovered when land exploration of the re-gion commenced with Captain Scott's first antarcticexpedition of 1901-1904. Since 1957, literally dozensof bodies have been observed by the many parties thathave undertaken field studies in the area.

Available information is not sufficiently detailed topermit computation of an accurate total of the num-ber of carcasses present. A minimum of 210 seal bod-ies have been observed in the three main dry-valleysystems; an additional 70 reported sightings may,least in part, represent duplication of discoveries.However, the University of Kansas field parties re-corded the locations of 106 carcasses in Taylor Valleyalone. Additional finds were reported from the FerrarGlacier by members of the Scott expedition and fromsmaller ice-free coastal valleys east of the RoyalSociety Range by several parties, especially those ofPéwé, who discovered 20 carcasses in and near G r-wood Valley.

In the Victoria, Wright, and Taylor Valley syster is,mummified seals have been found as far as 66 km n-land from McMurdo Sound. Most bodies are on ornear the valley floors, especially against easte lyfacing escarpments or other topographic situaticnsthat form cul de sacs impeding easy westward trael.A few seals, however, succeeded in climbing steepslopes or even isolated peaks before dying at elevationsranging up to 1,200 in sea level.

The occurrence of the remains of seal bodies at in-land locations in southern Victoria Land is not dupli-cated elsewhere in Antarctica. Carcasses observed by

210 ANTARCTIC JOURNAL

Soviet parties, for example, have all been at or verynear the coast. This may be a consequence of eitherthe dearth of inland ice-free areas or the lack of inten-sive exploration along most of the periphery of thecontinent. In 1966, a remarkable sighting and captureof a live crabeater seal pup at an elevation of 920 moccurred in Marie Byrd Land 113 km from the coast.

A distinctive pattern of cusps on the cheek teethprovides a means of ready identification of crabeaterseals. The skulls of many of the seal bodies in southernVictoria Land have been removed by souvenir collec-tors or normal ice and sand abrasion. However, 95percent of those bodies still retaining cheek teeth areof crabeater seals. Body lengths indicate that almostall of the carcasses, whether complete or not, are ofpups not more than 6 months old; some were hardlymore than newborn.

There is an extremely wide range in the degree ofpreservation of the seal bodies. Some are completeeven to whiskers, the pelt soft and pliable, bodyfluids still exuding. The majority are dried andshrunken, truly mummified, and have suffered erosionof upper surfaces by windblown ice crystals and sand.Others have been reduced to a few bare bones still ar-ticulated by remnants of ligaments. Close juxtapositionof seals showing sharply contrasting preservation sug-gests that there is a considerable range in the ages ofthe carcasses. Determination of these absolute ages is aproblem yet to be completely solved.

A seal found on the ice of Lake Bonney in Novem-ber 1966 is believed to have died within the precedingweek or two. The trail it left on the gravel surface wasreadily traceable from Nussbaum Riegel to the lake, adistance of 3 km. During 1966 and 1970, three otherseal trails were found in the middle part of TaylorValley. Comparison with manmade trails and otherfettures of known age indicated that a trail is easilyviible for only a year or two and will disappear after5 eears

Radiocarbon analysis of specimens obtained frommummified seals in southern Victoria Land hasyi ided ages ranging from 615 to 4,600 years. How-ever, antarctic sea water has significantly lowerca bon-14 activity than that accepted as the worldstandard. Therefore, radiocarbon dating of marine or-ganisms yields apparent ages that are older than trueages, but by an unknown and possibly variableaniount. Therefore, the several radiocarbon ages de-ter-mined for the mummified seal carcasses cannot beaccepted as correct. For example, the apparent radio-carbon age of the Lake Bonney seal known to havebe n dead no more than a few weeks was determinedto be 615 ± 100 years. A seal freshly killed atM Murdo had an apparent age of 1,300 years.

n the basis of all data available from repeatedFie d observations between 1965 and 1970, the writere ieves that the slightly desiccated seals have been

dead only a few years, that the mummified remainsthat still have intact or nearly intact pelts are no morethan 20 to 30 years old, and that none of the bareskeletal remnants are more than 200 to 300 years old.

A more complete report, with a full bibliography,will be published elsewhere.

Surface distribution of microorganismsin antarctic dry-valley soils:

a Martian analogR. E. CAMERON, H. P. CONROW, D. R. GENSEL,

G. H. LACY, and F. A. MORELLI

Bioscience SectionJet Propulsion Laboratory

California institute of Technology

Planners for future soft landings on Mars need toknow whether a single soil sample taken near thepoint of landing is likely to be adequate for analysisand life detection or whether several samples taken atvarious locations would be better. A Jet PropulsionLaboratory project in the barren dry valleys of Ant-arctica is helping to resolve that problem and othersrelated to Martian exploration.

Two antarctic dry valleys, McKelvey Valley andPearse Valley, were selected for systematic sampling ofthe surface 2 cm of soil to determine if a sterile soilcould be found in a specified area of the dry valleysand to determine the distribution, abundance, andkinds of microorganisms present within a given area.Samples were taken within a grid of 7,000 sq m (seefig.), chosen for its value in criminology (Hoffman etal., 1969), and were collected by aseptic techniques tominimize external contamination. The samples werekept below 30°C. at all times until they had been ana-lyzed for microorganisms and soil properties at the JetPropulsion Laboratory (Cameron and Conrow, 1968).

In the laboratory, an aliquot of each sample wasanalyzed for pH, Eh, EC, H 20 content, color, andMunsell Notation. Detailed soil analyses were per-formed only for the center pits, numbered 772 inMcKelvey Valley and 777 in Pearse Valley. Both pitscontained brownish or grayish oxidized dolerite-de-rived sands with 0.001 to 0.006 weight percent organic

This paper presents the results of one phase of researchcarried out under National Aeronautics and Space Admin -istration contract NAS 7-100. Logistic support and facilitiesfor the investigations in Antarctica and additional laboratorysupport at the Jet Propulsion Laboratory were providedunder National Science Foundation contract NSF-0585.R. B. Hanson provided assistance in sample collection. Bac-terial identification and physiology were given by R. M.Johnson, Arizona State University.

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