SlAle OF C.A.LlFORNIA~THf RESOURCES AGENCY

D\:P.A.RTMENT OF CONSERVATION

DIVISION OF MINES AND GEOLOGY BAY .A.REA REGIONAl OFFICE

380 CIVIC Ofi:IVE, SUITE 100

PLEAS.A.NT HILL, CA 94523-1997

PHONE, (415) 646-5920

ATSS -'99-5920

Mike Johnson Engineering Geology Group Dept. of Public Works County of Los /illgeles P.O. Box 1460 Alhambra, CA 91802-1460

Dear Mr~ Johnson:

• Gf:ORGE OE.UKMEJ IAN, Gc;i~l'f'lor

November l, 1988

we are placing on open file the following reports reviewed and approved by the County of Los lillgeles in compliance with the Alquist-Priolo Special Studies zones Act:

Geologic and seismic investigation for porposed residential development, Tract 19278 1 I,ots 23 & 24, Lake Elizabeth area, Los Angeles county, CA1 by Keith w. Ehlert, 8/19/88.

Geologic and seismic investigation for proposed residential development, Tract 19839, Lot 141, Lake Elizabeth area, Los Angel@s county, CA1 by Keith w. El\lert1 3/28/88.

Geologic and seismic investigation for propcsed rE!Sidential development, Tract 28075 1 Lat 2 1 Lake Elizabeth area, Los Angeles county, CA; by Keith w. E~lert1 8/6/88.

EWH: lr

cc: A-P file (3) v'

Sincerly,

Earl w. Hart, CEG 935 senior Geologist & Program Manager

• ENGINEERING GEOL.OGY QFIOIJP GEOLOGiC REVIEW SHEET

1213) 1313-2828 COUNTY OF LOS ANGE'. LES 0EPAAIMENT OF PUBLIC WORKS

550 SO. VERMONT AVE_, LOS ANGELES, CA 90020 0 Tract/PM ~2~8~0~7~5~--------- Lot(s) 2 Parent Tract Site Address 14533 Flintstone Geologist Keith Ehlert

LocatiorLake Elizabeth Developer/owner Kitt White

Soils Engineer ------------Engineer Joe Beckham

PLAN CHECK NO. OR OATE OF REPORT(S)

Review of: OGrading P .C. No.

J@Buildin9 P.c. No. --""2..,4 ... 6 • .,1.__ __ ~5,,.,f-1_,,18U-//·,.s""s.__ _ _..s,..F ....... R -· DGeologic Site Inspection Only P.C. No.

D 8.0 ist. Office ----

f XXXX NF_~-SHEET -1- OF 1

DISTRIBUTION;

_£ Dist. Engineec 1.. Geologist - Soils Engineer _1_ Geol. Group File

- Grading Section _1_ State of Cali!.

:laXGeologic Report Dated ---J1A.:i.1l~l;lifl'~llilit~.10;6,.,,.-1.._g~SocB>--41-'>91-i3~3;i-8=8--------------------0Soils Report Dated

Action:

© Prepare

48-00)

OGeology & Soils Report Dated

OPlan is geologically approved mP!an approved geologically subject to conditions below OSec. 309 Code requirements met (not met)

D Plan is not approved for reasons below O Submit plans for recheck

All recommendations put forth in the referenced report must be complied with. The propoted structure must be designed to withstand a maximum

repeatable ground acceleration of .4Sg (page 13 of the referenced report)

d by ___________ Date _...,l_O_-_l _1_-_f_~_

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August 6, 1988

Mr. Kirt White 2214 West Avenue 0-4 Palmdale, CA 93550

KEITH W. EHLERT Consulting Engineering Geologist

14 5 5 3 J-JLd-s-f6t.9-r- Q,. it' d,~ld

s. f· \).

rnrn@rnawrnoo Project No. 1933-88 StP 15 1988

PROCESSING CENTER LAND DEV. DIV •

SUBJECT: GEOLOGIC AND SEISMIC INVESTIGATION FOR PROPOSED RESIDENTIAL • DEVELOPMENT

Tract 28075 Lot 2 Lake Elizabeth Area Los Angeles County, California

• Dear Mr. White:

Pursuant to your request, the accompanying report has been prepared for the purpose of providing geologic information pertaining to development of the subject site.

a If you have any questions regarding the information presented in this report, please call my office.

ectfully submitted

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•

• 25500 Hawthorne Blvd., Suite 1240 • Torrance, CA 90505 • (213) 378-4146

• P.N. 1933-88 Page 1

• INTRODUCTION

• PURPOSE

e The purpose of this investigation was to obtain sufficient geologic

information to estimate on-site geologic conditions with respect to

propsed development of lot 2 of tract 28075 with a single family

e dwelling.

• SCOPE OF WORK

The scope of work performed for this investigation included the

e following items:

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•

•

•

* Gathering and review of iiVailable published and unpublished

reports and maps pertllining to the geologic conditions on the

site and in surrounding ilreas.

• Geologic review of aerial photographs of the site area.

Aerial photographs used during this investigation were reviewed

at Los Angeles County Department of Building and Safety offices

located at 550 So. Vermont Ave., Los Angeles, California.

• Subsurface explorlltion consisting of one long exploratory

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P.N. 1933-88 Page 2

trench. The trench was excavated with a backhoe .

* Preparation of this report with maps, trench and test pit

logs, and other graphics to present the findings and

recommendations .

SITE DESCRIPTION

The site consists lot 2 of tract 28075 located along the northerly

side of Flintstone Drive, Lake Elizabeth area, Los Angeles county,

e California. Figure 1 shows' the estimated geographic location of the

site.

e Generally, the site slopes gently northerly and was undeveloped at the

time of this investigation. The site appeared to have been recently

plowed .

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P.N. 1933-88

-·- ------ --··---- -------·~-....,

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Fii-taii Dll ' I

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~LAM~NTES • . . i

~ I . ~-f------".""J

I ' I

FIGURE 1

,:

• P.N. 1933-88 Page 4

• GEOLOGY

• GEOLOGIC SETTING

e The site is located in the westerly portion of Leona Valley. Leona

Valley is a fault-controlled topographic trough within the active San

Andreas fault system. At many locations within the area bedrock has

e been pervasively fractured, sheared and deformed and different rock

types have been brought in contact by faulting. The San Andreas fault

is an active fault .

• The site is located within an area designated as a Special Studies

Zone. Such Special Studies Zones have been designated along known

e active faults in California under the Alquist Priolo Special Studies

Act which was signed into law March 7, 1973. The purpose of this act

is to prohibit the location of structures for human occupancy across

e traces of active faults. Figure 2 shows the location of the site

relative to the boundaries of the Special Studies Zone.

e The Lake Hughes Quadrangle of the Alquist Priolo Special Studies Zones

maps shows what appears to be a trace of the San Andreas fault as

trending about through the site (Figure 2). The possible fault trace

e is shown as dashed, indicating the line was placed based on aeerial

photo linaments that were not field checked. Barrows et al (1985)

• I

•

f) / •.. ·

( ........ ······'

-·-----

• • •

llAP UP'&..AMATlON

.......... ~ ...... --F .... ltl COii II d I ed ID hnt '""'" ~... dllring Qu.m1emr; U...; IOICI ~ftll ....... ~ lllllc.-0, ilCW'I ..,. ...,._ a;ppro.I~ llDCat9CI, ""°" ..,... ................... dclaed ........ GOl"ICMliM; ;'. que,ry (?I ilndlcmell addftiloftaL ~'Y- l!'ll109h09 of l\iaklorlc D ..... WWllCalM by '9111' Of ..,,hOIJ ... MNCWIMI .-.nt or C ilDr dllll 1

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' .:..r:=:· :....· .. ~ ~--::-·:.::::a::-:-:··

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MODIFIED FROM ALQUIST PRIOLO MAP • LAKE HUGHES QUADRANGLE

P.N. 1933-88

• •

FIGURE 2

• P.N. 1933-88 Page 6

• does not show a fault trace as trending through the site. Barrow shows

e a fault trace located about 300 feet southerly of the site.

• SITE GEOLOGY

Barrows et al (1985) indicates that the site is underlain by bedrock of

e the Anaverde Formation. Figure 3 is a copy of a portion of Barrows

map.

e lnformation obtained from the exploratory excavations indicates the

proposed building site area is underlain by what appeared to be

a somewhat chaotic admixture of different rock types, including arkose,

e siltstone-claystone, and fine grained sandstone. The arkose and

sandstone appeared pervasively jointed and could be broken out 1n

relatively small chunks. Contacts between the different units appeared

e somewhat sharp, but no gouge or clearly identified faults were observed

in the contact zones. In general, the material in the test trench

appeared "melange-like". The claystone appeared pervasively sheared

e and contained numerous discontinuous random polished surfaces.

Figure 4 is a sketch-log of the features observed in the exploratory

e trench .

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•

Modified after B~~rows et al, 1985 ·

1-----------.----------'"""I Figure 3 KEITH W. EHLERT

Consulting Engineering Geologist P.N. 1933-88

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TRACT N2. 28075 M. B. T23 - PGS. 110 TO llZ

LOTS 1 TJ> 33, 5',54 a,.o n"' 7T

Thi• i:li ~ • MM"We'Y 9'I tlMI .. nd, .,t ie eompi1ad IO' ifi.forn·u111ion anly • .., ;. ii • 11ar1 of thti rnon .. .,at.MC't' •o whM;:~ 11 1111aw tM attKt..d .

Z4

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26

FIGURE 5

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P.N. 1933-88 Page a

STRUCTURE

No features were observed in the exploratory trench which indicates a

major through-going fault trends through the site, nor were any

• features observed during review of aerial photographs which indicate a

major fault trace trends through the site. Although the clayey

material observed in the trench contained randomly oriented

• discontinuous polished surfaces (shear surfaces), no features were

observed which indicate a major through-going fault trends through the

site .

• The melange-like features observed in the test trench are likely the

result of severe deformation due to regional compression. The site is

e located on a generally easterly-westerly trending topographic ridge

which is likely a compression ridge resulting from regional tectonic

pressures generated along the San Andreas fault .

• The sheared claystone observed in the trench may represent highly

weathered sandstone or may represent original sedimentary claystone

9 materials.

It is important to recognize that the site is located within an active

e fault zone. During the next 111ajor earthquake on the San Andreas fault

in the site area it is likely the site will be subjected to severe and

•

• P.N. 1933-88 Page 9

• potentially highly destructive ground shaking.

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P.N. 1933-88 Page 10

SEISMICITY

INTRODUCTION

As previously indicated, the site is located within the San Andreas

fault zone and is located in an area that is very tectonically active.

e Two major potential hazards associated with active faults which could

have a direct influence on the site are surface ground rupture and very

severe ground shaking. It is likely that for sites located in close

e proximity to active faults or located within active fault zones, the

most severe damage to structures will result from ground motion

(shaking) and permanent ground deformation as opposed to ground

e ruptures. Such occurrences were demonstrated during the 1971 San

Fernando earthquake .

• GROUND MOTION

e The severity of ground motion from an earthquake can be charlilcterized

either qualitatively from the observed or expected effects of shaking

on man and hie structures, or quantitatively from parameters that can

e be instrumentally recorded or evaluated. Quantitative parameters are

commonly util.LZed 1n design of structures. Experience has shown that

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P.N. 1933-88 Page 11

horizontal acceleration may be one of the more critical factors with

regard to damage caused by ground shaking resulting from earthquakes .

As such, the protential for on-site acceleration resulting from an

earthquake on the San Andreas fault system is evaluated and estimated

below .

Greensfelder (1974) indicates that data on the relationship between

• rock acceleration, earthquake magnitude and fault distance are scanty,

especially for accelerations greater than .2g. This is because few

strong-motion records have been obtained within 20 miles of the

• causative faults tor earthquakes of magnitude 6 or greater. In a

report summariZing rock acceleration data for the western United

States, only ten values of acceleration greater than .2g are shown

• (Schnabel and Seed, 1973). These are for earthquakes of magnitude 5.6

to 6.6. From these and other data, Schnable and Seed (1973) have

developed empirical acceleration versus distance curves for events of

e Magnitude 5.6 to 6.6. Their curve for magnitude 7.6 is an

extrapolation based entirely on data obtained at distances between 35

and 100 miles from the causative fault. The curve for 8.5 earthquakes

• is simply estimated because no near-fault data are available for such

large earthquakes.

• .Joyner et al (1981) use newly available data to extend prediction

equations to zero distance from the causative fault. However, it

•

• P.N. 1933-88 Page 12

• appears their acceleration curves for distances of less than about 30

• miles are based on earthquakes with magnitude less than 7.0. Within

about 1 mile distance their acceleration curves are almost flat,

indicating within about one mile of the causative fault acceleration

•

•

does not significantly change with distance .

Campbell (1981) has indicated that in the near field acceleration is

independent of magnitude and distance from the causative fault. In

addition, many of the commonly used tables show peak acceleration as _

opposed to repeated ground accelerations. Plossel and Solssen (1974)

• have presented data that indicates for sites within about 20 miles of

the epicenter of earthquakes in California the repeatable high ground

acceleration averages about 65% of the maximum (peak) acceleration.

• They indicate this concept appears valid for earthquakes of magnitude

5.5+ to 7+, and for larger quakes a similar relationship probably

exists, but suffieient near-field data is not available. Plossel and

e Slossen (1974) conclude that a repeatable high ground acceleration may

more closely approximate a "design acceleration" than maximum or peak

accelerations. Page et al (1972) have noted that a single peak of

e intense ground motion (maximum or peak acceleration) may contribute

less to the cumulative damage potential than several cycles of less

intense shaking. Therefore, it appears that repeated high ground

• acceleration should be of greater concern in structure design than a

single peak of maximum acceleration .

•

' P.N. 1933-88 Page 13

• It does not appear that adequate data is available to predict

I near-source accelerations. However, based on known available data, and

review of various rock acceleration versus distance and earthquake

magnitude tables, it appears that if a magnitude 8.0 earthquake were to

' occur on the San Andreas fault in the site area, a maximum or peak

acceleration of about .75g occurring at the site seems reasonable.

Using the concepts presented by Plossel and Slossen (1974), this

' corresponds to a maximum REPEATABLE acceleration of about .4Bg that

could be expected in the site area.

• it is important to recognize that the above evaluations are based on

very sparse data and much has to be learned about ground accelerations

resulting from earthquakes, especially in close proximity to the

causative fault, such ~s the site. for example, a peak acceleration of \

1.25g was recorded at Pacoima Dam during the San Fernando Earthquake

(the largest acceleration ever recorded). Although this apparent

anomalous reading may have been influenced by topographic and other

considerations, it does demonstrate that much more needs to be learned

regarding accelerations from earthquakes. In addition, during the

recent Whittier Narrows earthquake, a ground acceleration of about .6g

was measured in the Tarzana area of the San Fernal':'do Valley, when much

lower accelerations were measured much closer to the epicentral area.

An added consideration when evaluating peak versus repeated

accelerations is whether more than one "peak" acceleration might occur

• P.N. 1936~88 Page 14

• during one event. Such an occurrence appears to be a realistic

• possibility, especially for sites in close proximity to the San Andreas

fault .

•

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GROUND RUPTURE

The effects of ground rupture or ground cracking resulting from

earthquakes can have profound significance for buildings, including

single family dwellings such as proposed for the site. Earthquakes in

~ California can be accompanied by surface ruptures or severe ground

cracking. Surface faulting is rarely confined to a simple narrow line

nor is it necessarily restricted to known or identified fault traces.

• During the San Fernando earthquake, a relatively wide zone of fault

breakage occurred where no faults had previously been recognized. The

significance of this information with regard to the site is that it

• indicates that when an earthquake occurs, ground ruptures may not

necessarily be confined to known fault traces, but rather could occur

almost anywhere in the vicinity of the causative fault, including at

• locations where no known faults exist. As such, it is important to

recognize that although no active faults have been identified as

trending through the site during this investigation, the possibility of

• ground ruptures occurring within the site during an earthquake cannot

be ruled out .

•

• P.N. 1933-88 Page 15

• As previously mentioned, it is also important to recognize that perhaps

• the greatest damage resulting from an earthquake could be the result of

severe ground shaking and ground deformation. Some modern wood-frame

houses, presumably built to code, collapsed as a result of shaking from

• the San Fernando earthquake, yet some structures located directly above

fault ruptures did not collapse. An added factor is duration of

shaking. Some earthquakes have a longer duration of shaking than

• others. It appears likely that during the next major event on the San

Andreas fault in the site area or 1n aouthern California, the duration

of ground shaking will have a direct influence on the severity of

• damage that occurs to atructures .

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• P.N. 1933-88 Page 16

• CONCLUSIONS AND RECOMMENDATIONS

• GENERAL

• The conclusions and recommendations contained in this report are based

on information provided to this consultant, information gathered,

geologic evaluations, experience and professional judgement. The

• recommendations contained in this report should be considered minimums

consistent with industry practice. Some degree of risk is associated .

with any development. More rigorous criteria could be adopted if lower

• risk of future problems is desired. Usually the lowest risk is

asociated with the greatest cost of development.

• No features were observed that indicate active faults trend through the

site. However, it is important to recognize that considerable risk is

associated with any a site located in, or close proximity to, an active

e fault zone. Although the risk of ground ruptures directly affecting

the proposed development can be reduced by avoiding building across

known active or potentially active faults, the possibility of ground

e ruptures occurring anywhere in proximity to an active fault, including

within the site, cannot be ruled out.

• It is a.lso important to recogni.ze that it is likely the greatest damage

resulting from an earthquake in the site area will be from severe

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P .N. 1933-88 Page 17

ground shaking and possible permanent ground deformation. The San

Andreas fault is an active fault and it is likely a major earthquake

will occur on the San Andreas fault in the site area during the life of

the structure .

COMPLIANCE WITH CODE SECTION 309

Provided agency requirements are adhered to and good construction

practices are followed, as well as the recommendations in this report

• are followed, it is this consultants opinion that the site can be

developed without hazard from landslide, slippage or undue settlement

and can proceed without adverse impact on adjoining properties .

•

• GRADING AND FOUNDATIONS

The project soils engineer should make appropriate recommendations with

regard to the suitability of on-site materials for foundation and/or

• fill support. All fill materials (other than minor landscape fills)

should be placed under the supervision of a soils engineer.

The project soils engineer should provide foundation design criteria

e for all structures, including retaining walls, etc .

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P.N. 1933-88 Page 18

• A very important consideration is that the site is underlain by

I differing rock-types. It appears that t:he foundations for the proposed

structure will "straddle" the transistion between differing rock types.

It is important that the soils engineer take the differing

I characteristics of the these materials into account. Otherwise, there

could be a significant potential that the foundations will perform

differently from one portion of any structure to the next, possibly

resulting in cracking, etc.

The clays observed in the trench appeared highly expansive.

The project soils engineer should provide recommendations pertaining to

the steepness of any cut or fill slopes.

A mimimum of 20 feet horizontal distance between the bottom outer edge

of any foundations and any slope face should be maintained unless

otherwise recommended by a soils engineer.

A soils engineer should make recommendations with regard to bearing

values of natural and/or fill materials for foundation 6Upport.

It: is recommended that extensive water proofing be provided to

prevent moisture or water damage to the interior portions of the

structures it retaining walls will be used to form portions of the

• P.N. 1933-88 Page 19

• interior walls of the structure. The architect and/or engineer should

e provide details of the moisture proofing system to minimize risk of

dampness and/or direct moisture damage occurring. Even though it

appears groundwater may not be a significant problem at this site,

e extreme care should be exercised in sealing walls and floors against

water and water vapor migration .

•

• DRAINAGE AND EROSION

The project civil engineer and project soils engineer should make

appropriate recommendations with regard to erosion of any natural or

e man-made elopes incorporated into the site development. The project

civil engineer should also make appropriate recommendations with regard

to site drainge and drainage control .

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FAULT HAZARDS SUMMARY

As previously discussed, no major through-going known active faults

were observed as trending through the site .

it does not appear that sufficient information is available to

• P.N. 1933-88 Page 20

• accurately predict near-source accelerations tor sites in close

e proximity to the causative fault. Existing information, including rock

acceleration versus distance and earthquake magnitude tables, suggests

that if a magnitude 8.0 earthquake were to occur on the San Andreas

e fault in the site area, a peak acceleration of about .75g could occur

on the site. It is important to l'ecognize that this evaluation is

based on l'eview of various tables which, for sites close to the

• causative faults and especially for large magnitude events, are

essentially extrapolated since near-soul'ce data is spal'se.

• The possibility of higher accelerations occurring cannot be ruled out.

The site will likely be subjected to severe ground motion during the

next major earthquake on the San Andreas fault in the site al'ea.

• although the possibility of ground ruptures occurl'ing within the site,

cannot be l'Uled out, it is likely that for sites located in close

proximity to active faults, the most severe damage to structures will

e l'esult from severe ground motion (shaking) and permanent ground

defol'mation as opposed to ground l'Upture.

e It is also important to l'ecognize that pel'manent changes in groundwater

level can occur as a result of earthquakes .

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P.N. 1933-88 Page 21

ADDITIONAL CONSULTING

Any additional consulting, such as for foundation reviews, grading plan

review, response to regulatory agency reviews, etc. will be performed

• on a time and expense basis .

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COMMENTS

The conclusions and recommendations presented in this report are based on research, site observations and limited subsurface information. The conclusions and recommendations presented are based on the supposition that subsurface conditions do not vary significantly from those indicated. Although no significant variations in subsurface conditions are anticipated, the possibility of significant variations cannot be ruled out. lf such conditions are encountered, this consultant should be contacted immeditately to consider the need for modification of the project .

This report is subject to review by regulatory public agencies and these agencies may require their approval before the project can proceed. No guarantee that the regulatory public agency or agencies will approve the project is intended, expressed or implied .

One of the purposes of this report is to provide the client with advice regarding geologic conditions on the site. It is important to recognize that other conultants could arrive at different conclusions and recommendations. No warranties of future site performance are intended, expressed or implied .

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REFERENCES REVIEWED

Barrows, A.G., Kahle, J.E., and Beeby, D.J., 1985, Earthquake hazards and tectoni~ his~ory of. the San Andreas fault: zone, Los Angeles County, CalJ.fornJ.a: Cal.if. Dept. Conservation Division Mines and Geology Open File Report 85-10 LA.

Beeby, David J., 1979, Geology and fault activity on the Lake Hughes segment of the San Andreas fault zone, Los Angeles County, California: Calif. Div. Mines Geol., Open File Report 79-2Lll.

Campbell, Kenneth W., 1981, Near-source attenuation of peak horizontal acceleration: Geol. Soc. America Bull., v. 71, no. 6, p. 2039-2070.

Greensfelder, Roger w., 1974, Maximum credible rock acceleration from earthquakes in California: Calif. Div. Mines Geol., Map Sheet 23 .

Joyner, William B., Moore, David M., and Porcella, Ronald L. 1

1981, Peak horizontal acceleration and velocity from strong motion records including records from the 1979 imperial valley, California, earthquake: U.S. Geo!. Survey Open Filo Report 81-365 .

Kahle, James E., smith, Drew P., and Beeby, David J., 1975, Geology of of the Leona Valley segment of the San Andreas· fault zone, Los Angeles County, California: Calif. Div. Mines Geol., Open File Report 77-2LA

Page, R.A., Boore, D.M., Joyner, W.B., and Coulter, H.W., 1972, Ground motion values for use in the seismic design of the Trans-Alaska pipeline system: U.S. Geol. Survey Circular 672, Washington D.C., 23p.

Plossel, Michael R., and Slosson, James E., 1974, Repaetable high ground acceleratins from earthquakes-important design criteria-: Calif. Geology, September.

Ross, Donald C., 1969, Map showing r~cently active fault breaks~ along the San Andreas fault between Tejon Pass and Cajon Pass: U.S. Geol. Survey Miscellaneous Invest. Series, Map 1553 .

Schnabel, P.B., and Seed, H.B., 1973, Accelerations in rock for 'earthquakes in the western United States: Bulletin of the Seismological Society of America, v. 62, p. 501-516.

Sieh, Kerry E. 1978, Pre-historic large earthquakes produced by slip on the San Andreas fault at Pallet Creek, California: Journal of Geophysical Research, v. 83, p. 3907-3939.

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Sieh, Kerry E., 1984, Lateral offset and revised dates of large pre-historic earthquakes at Pallett Creek, southern California: Journal of Geophysical Research, v. 89, p. 76~1-7670.

Weldon, Ray J. II, and Sieh, Kerry E., 1985, Holocene rate of slip and tentative recurrence interval for large earthquakes on the San Andreas fault, Cajon Pass, southern California: Geol: Soc. Am. Bull., v. 96, P 793-812.

Wenousky, Steven G., 1986, Earthquakes, Quaternary faults, and seismic hazard in California: Jour. Geophys. Research, v. 91, p. 12,587-12,631.

Youd, T.L., 1973, Liquefaction, flow, and associated ground failure: U.S. Geol. Survey Circular 688, 12 p.

Youd, T.L., and Perkins, D.M., 1978, Mapping liquefaction-induced ground failure potential: Proceedings of the American Society of Civil Engineers, Journal of Geotechnical Engineering Division, v. 104, no. GT4, p. 433-446.

Ziony, J.I., 1985, Evaluating earthquake hazards in the Los Angeles Region-an earth-science perspective: U.S. Geel . Survey Prof. Paper 1360 .