srATE OF CALIFORNIA-THE RESOUR.CES AGENCY

O<?ARTMENT OF CON5£RVATION

DIVISION OF MINES AND GEOLOGY DIVISION HEADQUARTERS R'~SOURCl:;S BUILDING, ROOM 1341

141~ NINlH STREfT 5ACRAM£NTO, CA 9~814

01.i;trict Offices; tOS ANGEL'ES

Jurii1>4ro :;iMra 8fd!:j., Rm. 106!i l07 St;u.th B1<1e1dway 90012

SACRAM!:t-ITO R~«iuti;tis Bl<lg., Rm. 118 1416" Ninth Stn!tet 9.;5214

SAN fllAN<;:ISCO F&rry Building 941'1

June 13, 1975

Mr. Darwin Myers Contra Costa County Planning Department P.O. Sox 951 Martinez, California 94553

Dear Mr. Myers:

~ONALt> RCA.OAN, Governor

We are plac;lng on file the 'following geologic reports, approved and submitted iii compliance with the Alquist-Priolo Special Studies Zones Act:

EWH/mkr

Subdivisions 4476 and 4410, Danville, dated May 8, 1975, and May 9, respectively.

Sfocerely yours,

EARL W. HART Geologist San Francisco District Office

cc: State Geologist

... --·

TO: File 4410 anJ 4476

CONTRA COSTA COUNTY PLANNING DEPARTMENT

DATE: Mriy 20, 1975

FROM: W. Uarwin Myers RcgistcreJ Geolo2i•t 3164 P] •.lnrri ng Geologist

SUBJECT: l\rh;qunc.y of the Alquist-Priolo Geologic Repo1•t:s

~' \ '::}.,r..i'._1 \)~ .. ~,,-·, .. ,\ ·':.~.t~-~:.:~=-:~ -~·----·-···-···-·

Pursuant to tlw :requirements of the Alquist-Priolo Act a geologic study was conducted on tlrn site of two ad_i<lcent subd:ivis:ions (County hie 4410 uncl 44761. The study was con<lucte<l hy a i;eologist reg·istcred in the Stat" of ~California an<l the primary conclusion of the rcsul ting nipc,.rt ·is that there is no ov·idence of an active fault t:ruc..:e c,.~ross.ing the study area. The T1.~pOl't has been rl~Vit1wed n.nd :Jpprovcd by the County _ _l~lanqj__~~Jl....CE:~ulog·i~t. This mcn10 constitute; my review of th" r"ports "nd my comments of the geology of the study nTl~n ..

l. Cor11ply with provision of the Alquist-Priolo 1kt. Spe<:.ifically, "tech­n:ical ly q1rnJ.ified p<H'SOTlnd w:ithin or retained by each C.ity or County must evaluate (review and approve) the geologic reports required herein and udvise the body having juris<liction an<l author:ily."

2. Lnsur<' that the ocope and direction of the geologic study (and rcs1JJtin1; recommendations) anl appropri ute for the nature of the proposed devdopment and its geologic setting.

~-t::;:1_nwnts on the Study Arca

The Study Arca includns appr·oxirnately 10 acres which is situated i11 the Sun J(u.rnon Valley, cast of Interstate lli1;hw'1y 680 (sec Map 1). This area 1 ies in the Sped al Study Zone whieh encompasses potent b 11 y act i vc and recently active traces of the Caln.verus ;i.nd Pleusanton faults (offi chl maps d:.l.ted ,.JuJy l, 1974). Although no st1::>pl~ct.ed trtic.es hove been maµpeJ through the s:Ltf:~, the IYtojection of an air photo 1inoation shown on t11e Special Study ZorHe 111:1p would cross the study area (sec Map 2). It. should be cmphat:iizcd that the air photo 1 int:.~r1t·ion is not known to be fauJ.t related.

Befnl'e initiu.t:ing this review 1 lrti.ve <LIWlyzcd the 197:1 black and wh:itc, vertical-angle aerial plrotogruphs which arc available 111 this office

,

File ,1110 anJ 1\476 -2- May 20, 1975

(sea lo 1 ·inch = 1000 feet), and l'<OVicwccl pertinent published and unpuhJ i.shcJ geologic rcporLs which provide insight into geologic conditions in the study area, including the geologic rcport.s for SubJiYision 1336, 1254 und 4502.

\Vith TogarJ to the limitations of th.i.s review it should be notcJ t:hat J 1v,1s not rrre.scnt in the field during on-site trenching. Consequently l <..:Einnot (:ommcnt on the ,1ccuracy of the f:idd observatiun. !-i()wc.ver, I have carefully studied rhe informat.ion prw;ent in the l'(oport, ·i.ncluding the mar;netic profiles u.nJ l have 1nudc a quant'.it.utive nnalysi.s of the s~~:i::;mi.c refract.ion t:ruvcl t.ime ~

di stance curves. Conscq>H"ntly l om familiar with hotl1 th" approach that was taken ancl the data and I 1!0 feel that l can evaluate the sounJness of the con­clusions .reached by the consultants.

It is my op·inion that the study which was undertaken vJas comJrrt"!hcn~c and that. H compl .ies whh the provi<;_~on of t.hc Alquist-l'riolo Act [Scct.i.(lns 2621-2625, inclu~;ivc of the Cnlifornia Pt1hlic Rt.~sourc:.e~ Co<le). 'l'h1;.~ geologic and geophysical investJnntion wu5 directed t.o the pote11t-i.aJ. for surfucc f11ult Jispluccnlent throtlgh the sit.t:, a1"ld conc1 l.ldcd on tho l'n,1..sis of 5urfcice nnd suh~

surface data that no evidc11ce of an active trace is present on the sit.e. It shoul cl be emphasil.ed that. the review of pr~vious li.ter1.1turo and bl hliog·raphy of acr.in.l photographs are well. docunw11ted in tho repon:. The subsi1rfacc exploral. i.on program i.ncludud th rec ground magnetometer r 1'avcrses (:1, 100 l i11eol feet) ancl four seismic rcft·uction lines (1,185 lineal fe1'1.). Jn each case tfw lines wcrt.~ oricoted approxi.rn;i.tcly eust-west J at rip)rt ungle~ to the inferred troce of suspected faults.

Mcignetics. As ti result of the magnetic investigation a noTthwest trending anomalous ,,one wns identified. As with all potential field data, it is not possible to deternii.nc hoth the shape and depth of tlrn bo<ly produ<':i.ng the anomaly. As n. consequence of th·i.s, w0 need good geologic control in order to 1rn.1kc realist.ic. intt.~rpretr1tions. It ls possible to nHi.kc some qurrlitat:ive inter-pretat.Jons of magnetic duta. ~or exu.ffiple, shaTp anomnlics urc as.sociat.ed with shallow .structure; more :=;ubdued anon1alics n.rc gener.:il1y cissoc.::iatod v.·ith deeper sr.ructure. Reviewing the magnetic dat<l in this f·tumc of reference, J see the following:

(1) There is a br\nl.d magnetic: hi.gh wb:ich is in all probabi.llty associated with rclativcl.y Jeep st:ruct1.U'e. ·There is no 1bta on the magnetic:. sus(· . .,ptabil.ity of alluvium und h~~drock in this area, rnak.l.ng even a se1r'J:i.~qun.ntitativc una1 ys. ·i ~:; of ·ma~~nt~t i c p rofi lcs unrca 1 ·i.~t ic.. Tht::.re is no cvJ dence thHt the brood anomaly is f1111.lt related. However, its origin Is not established by cx·isting data.

(2) Tlrn only sharp (shallow) "nomalies are coincident with huricJ utility lines.

Seismic Survoy. A se.i.smic refraction survey revcalocl a . .scis1nic anomaly which is cl oscly co lncidont. with· the broad magnetic anomaly. The tnivel ti111e-distance plot for line S-lA rcsemhle.cl the classic anomaly which v;ou·ld be produced 11y n

' ~3- May 20, 107.S

vcrt:ic.:tl dip fault, w:it.li tho ea.st side upt.hrown. My ~ir1.::ilysis of the dnta suggests that a refracting ho.c1zon w.i. th a P-wave velocity of upp.r.·oximatE;:"ly + 4950 feet/second occurs cast of rfte anol!lalous zo11e at a depth of 19.S f'i'et-. Vw'ost of the anornu.lous z:ono this ho:rizon occurs at a depth of 2S. 5 fl.H.:~t -Ther~ is no unoqLJj_vocal cvicler1cc thfi.t tl1Js anornu.ly is fa11lt relotcJ.

Tron'.~hing. To provide evidonc~ on the near :::urfaC.f:.~ c.ha·ra1,:.ter of this Sl-::i:smic unomaly, a 10 foot deep t.rcnch was cut a<..'.Toss tho anom:-i.lous zone. Ther<.,~ was no evidc.nc~~ of fuult.·.ing in this. trcnc}1. The consult'.;:Jnt also revi.ev.·ed the rcsult.s of offsitc trenching on Subdivision 4:·;y; (perfoTm<ed for model homeo). Whik the trcnch~s on Subcl i vision 4."l.'I(, are west of tile mapped location of t.Jw annm::llo11s zone, they do provide .insight into geologic <.,:onJitions found in near prox.imity to the geophysjc.al anomaly.

In. cont"::lu.sion 1 the c.onsult;1nt fjnds no evidnncc of surface fuulting .in tho upper 15 feet of a1Juvi•1m on t]1c site and tl1e origln at1d sig1lificl1nco of rclr1t.ive1y de~p );E"~nphysica.1 nnomal-i.cs rE..~mains uneerta.in. It is pert:inent to note thut no one hus c~vcr mn.ppctl ri suspected fa.t.11.t t·rru .. ·.c through the site and all availal)le informn.ti.on suggests tli:.it rhe ctetivc trlico of the Cal11vcn1s fault closely co:incides with the hi.lls whid1 dGfh1c th" west side of t:he San Ramon Valley.

lla.'C'CI 011 the propondcrartcc of cv.idcnce I conc·.ur w.i.th the findings of t.hc consultanl:.

WDM:hf

er...~: Pet.er l~n.lda1.-:c i E. ,J. lledri.ck Murray Levi sh Earl !fort ,,-- · .Ji.m S<lflTfUS (2) r; le 4410 f'tlc 447G

/

KAY BUILDING COMPANY

May 19, 1975

Contra Costa County Planning Department P. O. Box 749

P. o. aox 1556 880 HINCKLEY ROAD

8UFU .. INGAMI:::, CAL.,IFORNIA 94010

I 4 15 I 692-3555

Martinez, California 94553

Attention: Mr.Darwin Meyers

~:o.~J l'J1·:

.~~· ! .. ;.', .~J f,_. ~·.

Re: Tract #4410 - Seismic Hazards Investigation

Gentlemen:

In answer to your request I have enclosed another copy of the Geologic and Seismic Hazards Investigation report from Burkland and Associates.

Very truly yours,

KAY BUILDING COMPANY

ft ~ '"(k.li{ll.t\. E. J~edri ck, Production Manager

EJH:bt

csor.oc:·1 c 1\ND ~)JU~3MIC J l:\ZL\Jrn~; ·1 NVEST:LC1\'J'ION

JJ,mvi I 1,,, Cu11i."a Co,;u1., California

... '",. ··:,'

\ -. ,' ,,,,-~.-·;' :- .- ; "'~-j

~ ".··:·.-'' : ( <'::J,-~/~

l

C";COLOCIC AND :rnlSMIC Ili~%/1.RllS INVESTICATION

SUB DIVIS ION Mf10

Danville, Contra Costa, California

Prepared for

KAUFMAN AND BROAD, INC.

Burlingame, (;Glifornia

By

rmRKlAl!f) AND Aco:WClA'.l'ES 333 Fairchild Drive

Mountain Vi ow, Cnli.fornia

.. HAY 1975

1

1 J I

·I 1 1

1 t

1

·1

and AssocIATES CONSULTANTS IN ENGINEERING GEOLOGY •GEOPHYSICS ENVIRONMENTAL GEOLOGY • SOIL AND ROCK MECHANICS

333 FAIRCHILD DRIVE • (P.O. HOX 820) • MOUNTAIN VIEW, CA 94042 • (415) 969-3990

Filc·ua. J:5-024G-MJ. :May 9, 197'.i

l(Clu.fr.;t11!. ~t1.·1<.l }~1·1).:".t::.I.~ l"l'J(·,~. ARO Hincl<lcy Ro~,d I~·\·: ... ··.1 ir1g,~-~.·; ':1: ~ cr1.!_ir(:/."1""1.:i .. t~.M

Attrenti..oo· )'.·. E •• J. Ji, ';_·:i_c! _,

Sttl:~Jccf.:: :3l·d.~cl:i.v i.:1~~.cn1 lp:'.~1.0 Dauvllle., Conl.:x.· Co;·.:iJi Co•.·. :.:y, Ccoil:i.fc ··ni_n GEOLOGIC AND :;J,.:: :;dIC I!A.ZARU:o Il\v.;::;TJi:ATJO:\

Gc:.1 i 1 c.·.utc.1·1:

We .: 1.1~c~ l)].(~:,:::~:(',(l i \1 t:;~l)T:; .. i 1': t·:1:1c tl.'l :1-. .:1<:.h(~cl ·1~·c-i_r)o1~1-.~·CJlJ SlI1:"Jdiv5_~-;j_(,~ . ."1. ~!1.Jll,

C<.: ·_·i;a Cof:LJ. County, Ca).:i_:l'orn:i .-

rrl·1c p1--ilTiflJ~ r fj'n,-·1·'._~."lf!, (1{ tl:l~'. .,. il1\i~(~Stit,\ :f·:f.r:.Jl.l is tl1~tt"· tbC·."''(~ f.l.1:0. l")O a(·. t·• \·1r~ o·1· \''' f· .·,,. '. :! ·1" ~,.' ,· v· ,., f' ... i1 ·1 .. t ·1 ··1 .• ', c· ,·.- ... ,·11.:: 1..· -~, ,.,,.,. f- ·,., ,_. ~-.·, i' t·_, __ -_._.

. .L - - • '"" - \ • - .I ~-L -· ·-. ' - ' L "'. (.. •• -·· l- ·-' - ). -· •, '--'' ... Ll ~-· ',. -

It -,···,,---.-·--,-·,-.. -.· t 11•i· ,-J,•·v(·'I · ---,1- ( .. ,.,., 11-·c-,.,,,,_,,-J J'f- 1-\---, ••• , •. , .. ,._ . . ,,,, ,U.,.<.l).··l·.•.I .11.\ .... - .. l'j'I .. - .<.I., .... I ..... , ..... ·-- .. A\.:-L\..:.\.~'-11.i.l

Ji'lV.n.(1:.1.; .· ,~~·r1s of th:;.~.; J_~cr .~-:-i.:t a,rld. tL1 ' •. :'~e. of tl1c: ,.JL)il tln\..l. fot::.I"l(lDti(JI.1.

(~11gir1r';,J: cti:·c fc,llov1e.~.~.

Very truly yom:~1,

N•i. 194 ) . Ci:JiT;flt:D <. .1

fNGINffklNG - I

jb GLOLOGISl _ • .:.• ------: -:,:._'<;.' - , o· Op CA\.-'~

Copies: 5 to Kaufo,~n and Broad, Inc.

• MOUNTAIN VIEW SACRAMENTO SAN lJil',GO

FiJ.c No. KS-0246-Ml May 9, 197'.i

CONTENTS

LETTER OF Tl\ANSMITTAL

GEOLOGIC AND SEISMIC ILl\ZARDS INVDSTIGATION

I. INTROlllJCTlOL·'.

A. LocRtion and Dcn,·ipl .0n of Site ll. Purpose and Scop" C. M('thoc1" u[ Inv(•:o tigatic :, D. Geologic S<· .. tin2

II. INVESTIGATIVE PROCEDURES AND RESUL'J''.;

A. 'Literature rrnd M:;p Review B. Ac~:r:i_A.l 1.}llt)t0[';1-~--! ': l11terpre.liJ.\ ;! ()r~ c. GCOj:>hynic;.d_ Sw ·o,·;oy D. Geologic Rcconn:·issancc nnd Trench

Evaci.ic~l tio11

III. CONCLUSIONS AND EVALUA'l' I ON OF SEI'.311IC tL.\ZARTiS

IV.

v.

A. Evnluar-ion of Seismic l-Lzards E. S.ummnry of Conclu:oions

BIB'LIOGJ.\APIT\'

LIMITATIONS

APPENDIX: Geophysical Profiles

FIGURES:

1. Site Location 2. Sitf' Plan 3. Fnult Location and Air photo Lineations L1. Trench Log 5. ·Trench Log

1 1 4 4

6 8

10

ll

18

20

2 3 7

12 13

( i ·I ) nTJRKI i\Nfl i\Nll l\';';rwll\TJ:~

J

'

Fila No. KS-0246-Ml Muy 9, 1975

GEOLOGIC AND SEISMIC HAZARDS INVESTIGATION

I. INTRODUCTION

A. Locrttion and Description of Site

Subdiv.i.::1.on /:!fl(), hcr9i.nuf1:c·r. referred to as "the site"; is

part ol: l:he "Danville Station" :3ub,Jivision located cust of

Hi.;;hway GBO and to the :wuth Ly Faruiso Drive in the Danville

ai-c:i ,i.1· Contra Cosl;a C,Junty, CiiLifornia (Sec Figure l). It is

b:.d'' · .. :c!cl on chc cast by the So-.:•.:,,:,.,_.,, Pilc:i.f.i.e RailJ:uad, on cha

:;uuLi1 by otlicr par:ts of t:he D<.inville Station SL1bdivis.i.011, on

t:b" '.vest Ly J,'<.nds of Ma7,7,a, et al., and on the norl:h by Sub--

divi:;iou Lf!f76. Topog·caphically, the area io relat:i_·11ely flat with

a slight sh.p" to the eaf; ':, At the time of this i.l:vo;;tigntJon,

the :;ubdivision had been graded to form s.Lnglc-fami ly rcsidon-

rl. PurpoGe ancl Scope ------···-.---·---

The pl;n:pcsns. of this iuv<>:;t;:Lgat:i.on Wen'."'·' to idcntlfy and cvalLtal:c

:;·~ i.J Cl1Cf'; of

''

]_ lllJRKLAND AND ASSOCIATES

Pkt.S'!JM.EO EPICErtl'~;n Of AP"rtrI, 18. 1 1.lOG [l\.h:n-1QUM:l:: tv.G. 8. l

0 Q 0 ra A

l•.ll

JUH!·~ 10 I ll·U6 Wl.G. 7.0,o.~

SAN

J;:~PLANATION

tt~<;r.li:udi)

tt~7td 1:.u.J,J

H.a. 11n.l t_~l•.la ~.1•.r:ilf:\.ldU

<1.0 - 4.'.Ji 5.0 - ~l.9 ~.o ~ 6.'} ,,0 ~ 7.'}

,'l"';"lt·••··ie ::..~ o.o '1.1.. ... ,·ultu-l~ ~.i:- ffOlt?C:'i:~il ~o-::1rth'1lll'<ltetJ

i''iiJUr~~ h4!>11ldi:i tlJq laci\1!:1•~n11

nurri:J('rt" o! n11r(:.ht-;udkeiJ. ar; tJ1•~

«J.1 ....:j\1"1l to o~: t11r>.o..\lo;(" th.n plotted.

LA N 0

0 " 16 j>.,,",C'.':'! :·;:-::::·51.i':.~::::>

SCl~LE lN t-,.1JL!='.S

I

• I _,,

FAULT

,. ,r' ' ....., ... ,.. .....__,

/

/ /'

STANISLAUS

( I

At~·t:iVi.~ ancl potr:nti;:illy active f~111lt.:::i: neur t}1r::: sti1·dy «rea. Scl•;~;·;.- i·; . .::.··~.l "="~;.··.:.- ·::.iHruakc8", n1aqn.L !::1,,du 9re.:1 tei:· -:~h<J.n 6. 0, that (.)ct;ui;rcd pr it}..I:;"

to 1 '.l J·.:1 ht1.-ve be.f~rt incln(:c(l 1.r1i th n.oto. l:jfJil~, cHrthrruakes l r~:;:-~ than r1\a(3n.tt·_ui'..le. 4.0 arc o..~\:i.ttc·rJ. DcJ.ta ~liqhtly 1;10dif.ied, main..\.~/ from l':alife.'-:"ni.:i Di.vision of 1'1.~~~e~, and Gcoloq~ Se_L~:;In.ic Sµfety Inforrnation ~~L>:-J72} ~ P···, :ioni.1.l f-·:tt1l1: tniJ.p of c,:lliforn.ia; anc.1 Pr-~liminary

c,:::ct.hqll"1<e epicenter rncop of Ce1.lifornia, 1934-1971 (June 30).

2 Fiqure

, I

" I

0

i

I J

i

l

1 l

'

Fil c No. 1(5-0246-Ml Mny 9, 19 75

M-2A

Scale in Feet rrrs;···5:;;;,,,e·::\=3

loo o 200 400

I ·-------'~ "',,, c.,.TRACT IJli7G

.'))

I\ n o 111,1 l o u s Lone

''))

s~ur Pl t1N. CONl.RI\ COST/\ TRACT 4410

Contra Costa County, California

Trench

--.. ·--·Site lloundary 1~ -·-·- --;$ e i s mi c Traverse

,._. --~ .. Mctgneto1neter Traverse 1-------; Test Trench

M-1 A: Tract 4476 M-JB: Tract 4410

BURKLAND & AssocJATES

J Fl.g1.1re 2

,J

:1

I . , I

File No. KS-0246-Ml May 9, 1975

active faults. The site is lcJcated within the "Special Studies

Zone" delineated by the State Geologist pursuant to the Alquist-

Priolo Act. The investigation of this property was conducted

corn,urr1~11Lly with a simiJ.cn: study for the adjacent Subdivision

!ff1-76 (Burkland and Associates Project No. lCi-0248-Ml). With

conoent of the owner of L:l"' adjac,•nt p1:ojcct, dai:.'.1 from that site

11as utilized along with tl1e results of the invcctigation at this

property in the preparation of this report. Thl.u report deals

witl1 ar1 cvc1ll1c1tio11 of i··:~cologii; and sei:JnLi.c 11Ltz..:.iJ_·ds a11J is not

i:·:umclwl to provide 0pec:iJi.c soil :x,1d foundali.un d<'sign c-rit<:'ria

.di tho preliminary goologic and soil i.ff·{r>stit.'/ttions th:1t had been

previously conducted at thi.s and the ttdjaccnC site.

c. ·----··-~-.·-

T1h.is i11·vc21 Ligat:io11 cot1f;:L .-.~ tccl ()[ a r_.cvi ew c.1.11tl cv.:-.i.'11.1,:1 ti on (}:[ £.lva:il-

i;2rpr~tntion of acrJ.aJ. photogrnpl1a of chu site JnJ vicinity, a

,s:~olog:i.c cxaminatlon of E'xplm:ntory tr<cnchcs .

~·r1c ~itc is located in the northern portion of Snn Ramon Vnllcy

·Hl1ich L; an alluvinl valley lyi.ng be.l~ween the hills of Las

. ·..::.

File No. KS-0246-Ml May 9, 1975

Trampas Ridge on the west and the foothills of NL Diablo on

the east.

The site is loectte<l within the limits of the "Special Studies

Zone" as def.Lned by the Stale Geologist pursuant to the Alquist-

Priolo Ac~t. The Special Studies Zone in Lhis area incl1.1dc's sus­

pected traces of the Calaveras Fault on the west side of the

valley and one photo lincaU.on Lo the sottlh that if projccLed

norll1wartl, would cross Lhe site.

Tl1e f'lluvial soils ir1 thiu vicinity co11s.lsL generally of an

upp<.'r layeT oI tl.cn·k b·c:.:· ,. silty elay,·; which are usually highly

cl~1ys .::!t1d se.;.:.cls, son1e of 1r1hi.cl1 111.:1,y coi1cai1i. "1)t~rcbec1" v1acor.

llfll(KL/INn t\ND t\SSOCTJ\TES

File No. KS-0246-Ml }fay 9, 1975

II. INVESTIGATIVE PROCEDURES AND RESlJLTS

A. 11 tera ture nnd Mnp Review

The most useful literat:u.re and maps pert1nent to this study are

l1!">tcd in Scc.:tion IV, •nDLIOGJ.0\l'HY. Most of the published

geologic information Oll the nrea 1s of a preliminary 11:tture,

( .• ,,. : - f- :'- •" • '~ •• , ~ J.

o[ the San R~rn1011 :JL·ea has been publ:i c<h·cd.

Nun1cron:> :E:wl ts arnl t;uspcc tcd L111l t t.Til cell have Leen reported

in the vicinity of LL1·, ·d_U.' (Sec · ·gurc 3, Fault Lo•.:ations and

A:i.r L'hoto Li.ncat·i.ons). None havo [)(,'en repor(:cd as pass:i.ng

t.hroL1gh the site. A p:1oto lineati·:;n shown on· the Special Studi,,s '

Zone :·lap, Ve ends cm1ard t:he site soLtth, but it 111 tc:nninatcd

south of the site.

The ca:r.tliqtF•ke of July '.3, J.BGl, wh1cl1 vas c'picenl:cred on the

Cn l_:,_vera'1 F.J.ult, repoi"t:odly nipt.ured and g·ronnd alon8 L:!1e west­

ern edge of ~an Ramon valley. Jennings (197'.3) portrays L:ho

:-.n1tbor.

F1~ULT LOCl\TIONS & 1-\IH PHOTO IJNEl\TIONS Cont1•J tosta Tract 4410

Contra Costa County, California

LFGEt!D

llam;;1 (1952)

---srabb, Sonnem.<n & Sv1i t::er ( 1971)

-....- !i , S • 1> • $ . ( l 9 7 I , ' 7 3 ) --C , 0 . rL G , . ("l 9 7 3 )

., .. , '! 'f'. '. ~

-----1\ir Photo Lineation, C.D.M.G. (1973)

__ O-·-- fJoundary of Sped.i l Stu di ·~s Zone

-,

Fi le No, KS ·-0246-Ml May 9, 1975

centered about one mile nvi:theast of the site nn<l '.'xtcnding

toward the northeast.

A review of the boring lop;s from the '.;oil Investigation Report

performed at~ tliis site (Gril"lldo, Jones and Aoisociatcs, 1971)

i.ncli.<~iltes 110 free water withi.11 the upper 15 feet o:E rJoil. Othe:t."

li<ffings (locations unknown) v .:1·formcd at Lhc sil:e in 1971

(Gril1aldo, Jones and Associates, Geologic l~zarJ Jtcport) lndi­

cau, groundw:1tcr levc.,lti '1t sornc locativus :tt a depth of approx­

·i·.Jatcly 10 feet. The• dc,.;cripti.:Jns of 1-b.· ma1:J~:rials i1:d-i.co.tc

()f ll:edi11Lt cler.1sity. (], tl1c bc!sis o.r: l:l1<)Sc-.~ (lc0£::cipt.Lot1s.:r :i..t

l·; ·, 1 nr~:ic·t·1.·rin ,.-r1 1"th1."t' ·t~1r.i iinn'-"'>J'. ... ' l' ~·~-·-~ ~~~ •• - L~ ~ k'~ ~-1:: ~~ ~·

15 feet of soils 1.S unlikely.

gc-1. t ion:

Date SoLtrce

3 I 7 I ss 9/02/70 lf/12/71. 12/1·1 /71 12/17/71 1973

J"<J. 01)() I

1 11 ~/f- (jl)() I

J1~lacl & white stereo bJ.ack ·:~ ~11ite stereo black '" white [) Lc'reo bl.:1ck [., ~vbit~c ir1f1~~f1·cd black & wl1ite infrared iaJ.se cu.I.ox: infnire<l

Pi:~cJ..[.Lt.: tzes<)t1J:cc~s,, Inc •.

:· ,)f()J::.'(~

1971(?)

' 1 11 ~1,000 1

1 1100 _1_,0()() /

l."=3,6()0 I

l"•"l,000'.

1"-,600' Llack &. ohi.te

II 11 I I

" II " Burkland & Asaoclo.tes

JI . "

II " Unknown

File No. KS-02!16-Ml Nay 9, 1975

These photos were scrutinized for the presence of terrciin features

chcirnctcristic of active fault zones, partic1.1lnrly lineations.

A li11ecit.lon shows on a stereo ncricil photo as a linear feature

with conal <lifferenccs on ench side. These tonal differences

ci-r.e dur: i:o chnnc;es :1.n !;oil color, ver;ctat:.r_on 01_· groundwater

level,3. In cireas of known acl:ive faults, tlu•y arc somcL:imes

rel.1L:cd to faulting.

No lincaL::i_,;ns wen,' seen ero~ising the site. Tim lincation de-

pictcd as trending t<;•\lard tlH• s:f.tc, on ti.le Specicil Stucli<)s Zone

}fitp_, conld 1•nt be seen cros,,:-ing the c:ite, on ;1ny of the above

photos. IIu·:·;ever, two pci.r:allcl no:cti.1we:1t/.,;outhe11:o:t· tn:ciding

'·1erc .;,,:en on the 12/17/71 ph.1to,;, scale 1" = 3,600'. An unin­

:.:crn1ptr,~d contact LcLween rc1ativ··1y deep nwl sbaliow .,_lluvium

(L1tcrprctcd) was cecn on the above photo~;. Tll0 cbarau~er of

this J:ca cure i.s inte·.:prc Led as incl:i.c:_1ting shallow IK•ch:oc.:k to

the west of the [J:LL<J. The ur'droc'k .Ls cont:Lnur>us to the hLlls

to the Wl'St,

the site or in the i11'meclia1:co vicinity.

·1

File No. K5-0246-Ml May 9, 1975

C. Geophysical Survey

On April 3, 1975, a seophysical survey was conducted on the

subject site and the adjacent Tract 4476 to investigate the

subsm;-face condition'; on both sites. The investigation consisted

of l:h:n'e ground rnagnetonietcr profiles totaling approximately

3, 100 feet and four rcJract.i_on se:i_:HnLc Surveys Lotnling ;;pprOX­

irnately 1,185 l i_ncal feet. The locations of tlrn 1na.gnetometcr

<ll\cl seisrni_c profiles 'lre shown on the S5.':e Plnn (r'igurc 2).

Th10 geophysical profil:~:J We're L.1 i_d out ;;-::ncrally pu:po11_:_1J::ular

The c;c_i_::nnic prof.i.les v1ere situated L:o v:<plore any anomalies

of L:lte geophyc:icill d: ca (Sf.'e iq)pendix fcir [>Lotted ~''' i_smic cbta

division lf!fl0. CmnpuLation o[ t1 :e ck;:i th to the gGophysical

anomnly ·i_ndLcates that i.l: is deeper than 15 fc,ct. The prec1'.JO

caucJe for this anomaly is uncertain. It waG x·•c•,;ommenrled that

a trench be exeavaceJ nt a convenient location to Intersect the

l:rend of the ~;eophysical m10maly t:o 1kten1\.Lne if il: was relaL:ed

to SJ.Wfnee faull:ing. A discussion of the trenching results is

incluJcJ in the following section.

File .No. K'.i-0246-Nl Nay 9, 1975

)). Geologic Recormaissance and Trench Excavation

The project site hncl been recc,ntly graded thereby altering tho

surface features which could be examined for indication of

recent fni.1lting. The s~i:n:nundinr; areas Wc'1:o exarn:inecl, howevor,

Ior any ov·i.,Jence of :fault c;_·eo]o) or <icti.ve faulting snch as

li.r1car d~p:1:(~flsior1s, st15 ·po11cls} offset sl:J7<~~11ns, 0tc. No sucl1

fr)atures w0re ob:w'l:ved whi.ch could bo rol.nted to fcmlti.ug w.l thin

the immediate vi c I.n.i. cy of the site.

tile lu··,;.ition shoun on FigLtre 2, Eecc.use Ll1c~ site had already

l1c;:-~r1 ~~~·c,;1clccl, t:1:1(~ loc~1tiort of tl1e trer1r_:l1 \'7(:1.S cl1o:·;c.t1 le) give

n~tl~{.i.1nunl il1fo1:ril;i i': t..01.1. .~1i.-tci to i .. '::::lst cliE"i'.."L11;t (::xis ti11ts r;t1_·ccc ~'1.)ld/o·r

Addi.l:ionalJ.y, tl1e geologic log of a trench excavated further to

tlie south b,_,llind the tnodcl homes adjacent to SL.tbdivision L:.!fJ.0

tlw conditions )hscrveJ in both trt'nches, it is concluJe.d that

tl1<:·rc is no geologic cv.i.dcnce for an act:ivc fai.1lt disturbing

1.:he upper 10 to 12 feet of alluvial soils.

A log of the trench cxccivated for tl1is invcr;tiz;at.lon i.s pre-

scntcd as Figure 4. Also enclosed for reference :ls a copy of

the geologic lo['; of the trench excavated bd1ind the model homes

foJ: the adjace.ii; Suhdivi:iion r+4l0, F:i.gure S.

I ! ~ I t I

0

r '- ~ .-,- ...,__ . .::.

Dark Gre_y BrOh'r! Cla~/2Y s~;.;. !:'_xr=~r-sive

Lt~ Tan Fi n.e S_.:.':"\ D, S\":::< \.'.:'.:! 11 '/ ~ ~ ,x ~ i~~ 1' .:::.1 Gr.~ v21 at

0 20

Horizontcl Scale: 1"~ 10' Vertical Scale: l"= 5'

..

40 60

LOG CF-TEST TRENCH NO, 1 CO~TRA COSTA TRACT 4~10

Cont~a Costa County~ California

-,.

"' ;z 0

East ?< '-~

0 I

I a N

East End _,. G\ I

3:

~

80

BURKLf,.ND ?... AssocrATEs

J4 - _ ..... -

-·-·-

. . . .J 0 '.J

. ~Y :!.. .1'.J.Vl~x :.·r . .:!e:- t'!-:.;i

·'

'

/C'..".;.u_....:-,e:.. oe~c::: it ,~,

• • Jiii • • Ii II •••

!/J ~\~7, ~e.::::, !.;, f'.ot.C...".';J"\ /' of '.tr<'.:::-,ch

Hor!:o~ta: rcale: i·~ 2C'

Ve=~ic~: s~~!G~ i~Q s•

Da~yil1e S:~t:cn . Db 1".'1'1l11!, C.!.1t:.orr.-1i!.

'·'" :.

--- .

- -,,

J

! I t

I I

l , i ! !·

rt>

~

0

7' <.n I a l'v .;>.

°' ::;:: ~

File No. KS-0246-Ml May 9, 1975

III. CONCLUSIONS AND EVALUATION OF S!'lSHIC HAZARDS

A. Evaluati.on of Seismic W.i;;ards

The San Francis<:o Bay Ar0a is scif;mic;ally activo, that is,

subject: to earthquakes. A f.:iult map of the central California

coa:;t was used a~3 thll base for Figura 1. Tho subject c;ite

could be affected by cartLquakes witl1 "'P:LC\c>nton; on any o:f. the

active faults in the Bay Ai:ea. At present, it is not po ;~;ible

to prodicl: whc::n ur whr_'·•;:' rnuvem.cnt will occur on these Lcults.

these :faulttJ ·.:ill r:>:ult in a mnr_[:,'rate to major c<nthquake

during tho life oxpeclancy of any oonstrugtion on the sito.

'j_'l-10 precise locnticn of the Calaveras Fault _i_s uot known i.n tho

vieini.Ly of the s:Ll:<'" The Eay.-1r,rd :Fault iH about 11 mlle:; wesl

and tlw San Andrea:; l•'.Tt1lt ';omc J2 ,.,,; le:'l west. Gr<.,·._tnd ·rupture

was rqiorled un th,, wc:st slde 0£ the San Rmnon Valley lll1ring

the c1irtli<[(1;.1kc of July 3, 1.851, which caue>ed <cxUms.ivc c.;:.:1c!dng

o.( the ground 1111<:l the "brcaklng out:"· of a 1mrnbc-r of springs.

The exact locatlon of the rup lure 1-/.'Js never documented, but it

has b(:en repOl't:ed at l:ln:ec location:) (SpH21tll S i:ucLios Z~ncs

Naps, 19"/t+, <lnll Jennings, 1973).

In tlw event of Ml etirlhquake, seismic risk l:o a structm:e

d•"rends on the di:J urncc of the structure from the epicenter

and sourc<' fa\11 t, tLc eharactm: of tho car t:hquake, the geologic,

1 /.

It '· I

I I

f!

! \

I I I f j

File No. KS-0246-Ml May 9, 1975

groundwater, and soils conditions under Lying tlw structure and

its immediate v:Lcinit;y, and the nnt·ure of the construction,

The damaging offcct;s of earthquakes arc classified as ground

·r.up Lure, ground [ailw:c and ground shaking. The v:imarj' "ffect

i" zround ·n:1ptu1:•••, also <.:cill<."l GLtr:[;-tco faulting. The common

secondary 2ffocts are:· ground failure caused by lique[act:Lon,

lurcl1 cracking, or l~Lteral spr:)ading uf ~oils, lCT11Jslides,

rcr;.i.onal 1;ub•;.i.dcuce or upl:i.:Et, and rnruct:ural. d<1.nu1ge due to

ground shaki.ng.

GJ>"J LLud rup t·.urc tends to occur nlung li11"3 of prcvioucJ Lml ti.ng.

gr:oLtml rLtpture cim be> con,iid•:1:wl n<.'gLi_z,,i.ble,

Tt1e seconJury SE·!ismi.~ effects c).f ~X()UDd failure, liquefaction,

hn:ch cracking, and lateral ~;pL1:,·1.di.ng are related to :·:oil and

to Le L:worable w:it.:h ·1:-:·:spe<.:t: to 1;lw IH:l.cential fur li.qucfnct.i.on

arid lurcl1 cracking.

l\e5io:.ul sLtbsidoncf' or nrl:LI1: t.:alu:s place ovrc.r lm:gc areas. In

·the e.vcnt of movc111e:1L rwcoc.i.atccl witlt an carthqu(1ke, tlrn 8itc

wol.lld probably rcc;poEcI a:.; a unit, n::,-ikJng darn:-tgo from this ·cause

unlikely.

l.5

!I ,. Ii I I I I

t

1 . '

j '

File No, KS-0246-Ml May 9, 1975

Structural damage.du<! to ground shaking is caused by the trans­

mission of earthquake vibrations from the ground into tho struc-

ture. The variables which determine tho extent of damage are:

the characteristics of the underlying earth matexials, the design

o[ the ~otnwture, the quality of mai:crials and workmam;hip used

in cono:;:ruot.i.on, the location ·.1nd magnitude of tl1c Cctrlhqmtke,

and the dura1:ion and i.r>f.·.:.)1dity of shaking. Tito rn.o~:t (k:st'J'.'LLetive

effects of an cn.rtl1quake. ure t.1!3ual1y seen wi.wre ·he groLmd is

sit:<~ indicate that: i.\ec,~lerations beb:vccn 0.2g LJ.nd O.:.lg CL\n be

:.lllt:icipated durirtg ti a;och~ral:•~ to major h\rl:hquakc on the nearby

Ca.ln.vc·ni.s F.:iult oJ: a 1nn.jor •':-1rthquake on L:he San L\uclreas Fault

The clLU:ation oE ,.,lwking w-i.:Ll be elope cdcnt upon the r.1agnitudc and

Hi

File No. KS-0246-Ml May 9, 1975

1. The i.nv<~sLigative tncthods employed proc!uced no

evidence for the presence of active faulting in

the upper 10 to 12 feel of material at the site,

2. ThE' potenl:ial for gi·o11nd rupture on the site is

considered negliBiblc.

3. The potc'ntL:tl for lirJuefaction and other seisrni-

cally induced g·i:ound fallLrrco, s11d1 as lurcl1

s i L:e.

Lf. The ;_>otcntiHl for :>truclural thr:;i.ge, dLtc t:o g·round

shaking :i.s min.imal if qucilit:y design and c;onscTLLC-

tion criteria arc met.

provJ.dcd t:hc rcco11m1('n•.latiorn; of the »oil and

_CC'-.lJ.ldnLi.or1 •~11.g i.Il{~t~J: a:.t·(:: i.r .. 1p1.'.":n1ct1tc<l_, .:111c.l i1:r.o~.f:Ldccl

accommodate 1n1L:i.<.:ipated ground sb.:1.klng diaracter··

I ~ I

! I

I I I I

f

,I

File No, KS-0246-Ml May 9, 1975

IV. BIBLIOGRAPHY

l. Brabb, L1;. E., IL S. Sonn<'man and J. IL Switr.er, 1971, PRE­LICiJNARY GEOLOGIC MAP OF ·nm MOUNT DIADLO-J',YRON ARFA, CONTRA COSTA, ALAMl·'.f"\\ !\ND SAN JOAQUJN COUNTIES, CALI:"ORNIA, San [i'r~1r1c-i..sco J).:ty .i.~r1vi:ro11n1c11L .:.111d ·Ilcsou·rces Pl~1·ur1i.ng Study) i~asi·c Dal:a Contril)uti.on 28.

2. Brown, IL D. a1Hl W. H. K. Le"'" l ') 71, AC'l'IVJ;; :';\UL'l'S AND PRE­LIMINi\tl.Y FA:ZTlJQUAl(J•: l.<:PICEN'l '':r-:s (1969-70) IN 'll!E ::ULTTHERN PAR'l' OF THE S,\.'! l'TANCl:CO J\i\'{ kl':CION, U.S. C'olo(\.L•~al Survey, Miscellaneou:; I'ic,ld S Lud:.i_(>o Map MF 307.

3. Burkland and Ac::_;ocial:cs, 197Lc_, CEOLOrac i':D ~lETSHIC l-lA%AIWS Hl'ii\STICAl'lON, CONSALVES l'ROl'ERTY, Contra Co:; t:'l County, Cal­iforn.i.a.

4. , I971f, Gl':OLOGIC ANll '.iEJSMIC HAI.ARDS

r ) .

6.

Tffi/"<.-i['i.ciXT'CoTr;-c;cJ'i~iJ"iji~TJALL F.'.DPERTY, cont-,-_,, cos ta County, Cali __ ,_'orni<i.

Cttlifo;_·u.:.:.: [):!1:.:-~ri u;c11~. of' f,.J~!tci.L· ~'..':'._;\_;:..1J.:.·ccs, 1J5JJ .L\I",'\t1T~C.i:\

COUNTY INVES'J'IC~TION, Bulletin lJ.

Cc-lliJ'eil."ll;c, lli.vi»ion of ines and G;"r_,-J __ oty, 19/1\, ALQUTST-I'J(IOLU ,._ '~]/\_"!, :':T' I:S ZL 'i,:s ;,rJ\p - 'HABLO i/TJl.LW .. \NGLE.

7. Davis, F. :me! H. J;. Cnl.d11;,3n, l'JSn, :H\E-S Al-JD Mili'.'V\L ru:smrnci;s OF (;:_)J\ITRA UK:TA COUNTY_, CAL 1.:FORNJA, California .Jou·n'Ll l_ of cU.nrc'S and Geology, Vo lulil<c SI" No. tf.

8. }~'.NC.El)_, I11c.} ]_ '...l J ~)} ~;XPJJ)TU\.}1 TC)N c:·:"!)~Lt.:·~;J.C 'l'F'..I 1:l\!CfI_, Dtrn.v:l.lle ~)tal:i.or1 11lodcl H.1J-n1e~:; .. 1.1~er:1, :1::, ::rvil.1., .. ~_, (~nlifoi:·i1i~l..

'). ford, R. s.' i_()G'), Ci:OUNJY.-71\TER c;r::o:LOGY OF LJ.VJ•:m,IORE VALLEY, rJt·b.::lr1 f<~.i1·vi1·c:)11tne1lt:,Jl (~.c~o:l.o::'.;.J' 1 /\ssoci.::1t:io11 o[ En.gi11~~ri11t1 c;eologist~; Sp~:-~ci.~:il Pld")li_c~.<.L.ic)rl.

10. (;1.~_i_1Jr1ldo:J Jcrn.es (tt1c1 .l\.sso(·!.:·i.i:~f3) 1971) ,_;]i;()lJOC.1lC l:f~\ZAl.Zl')S REPORT, Baldwin ·W.ild<,-'m:<«<. '.·:Jperl:y, ('-,ni:Lno Ri.lmon near Hansen L-:1:nu, Coutra Cor;tLl County, CnliLorni<l.

1 8

I ' [

l

l J

! 1 l

!

* . , j

File No. K5-0246-Ml May 9, 1975

11. Gribaldo_, Jones and Associat:t!s, 197:L, SOlJ. INVESTIGATION, Proposed Planned Unit Development, Baldwin-Wildenradt P1:operty, Danville, Califo;:nia.

12. Hm:.!.an Engint!ers, 1973, SOIL INVESTIGATION FOR TRACT lf!176, Conlra Costa County, California.

13. .Jcmnings, C. W. , 19 F.l, STi\TE OF CAT,IfOENIA PrELIMINARY fAUL'I.' AND Cl'.:OLOGIC \-'ci\P, Cc.1 L:i.forul<l Div.i.sion of MinC's and Geology.

1A. Nc>1vl:on' R. J. ' l ')Lf8' TUI•: r::wr..ocY NORTr:WE:;T OF DlIBJ.lN, CALJFOFNIA, Hf ·r:m IJlClNL! '{ OF Ui.VJD~: H'UJGE, unpublished M.S. '.Llwt;i~, Univ•.,r·:oity of Cal.Lfornlu, Bcrke>ley •

:LS. U. S. Department 1if ABriculturc, So.ll Consl!rvation Service, 19 7l1, CON'.ii.\A COSTA COUNTY SOIL o;uRVEY' INTERIM REPOR'l'.

File No. KS-0246-Ml May 9, 1975

V. LIMITATIONS

This report is based upon data obtained by surface reconnais-

sance, trenching, ;;eopbysical survay, interpretation of aerial

photograph:;, an<l review of z,eologie map:; and literature per-

tinent to Contra Costa Tract Lfff10. No infe·i:c:icc sholll.d bo drawn

froin the language of t.:he report that the scope of tl1e inv(~sti-

g.1 t i_on Wcl s any wider. It must be uncle1: :J toad t::lin t a 1 though the

oliserve<l a11<l reported conditions are considcred rcprescntative,

local v1-1riat.:·ions of geologic conditi·· ,,; ni<lY exist for wh·i.ch this

[inn cannot a10f;ume rcsponc;ibility. :No warumty aci to tho con-

tenL:i of this report is intendccl, Hild none (Jh<ill Lo inferred

pr<~po_red upon your rcqu::st foJ: our '.H'T'lice.s, and i1.1 .:iccordance

with accepted stancl<J.r<IJ of professional pracrice, The tr3ns-

mitt:al of t:his report to you completes our contn11~t reqLti.r.c.ment:>.

''

,,

·,, ',' , ... 1j•,'.:,

. •,:"

,,, ,. \~ .. '.f.

Profile~'

'·,.

'-~-~~ .. ~{:~:-;:'. :> . ~:.; ·>!~ ._; .. '',, .

,,.,.

.,.,

, ,, ~' ~,-~_r.

,. l~. < '"!

; .... '' \'.'

, '" .

,. ';~ ..

'.''

-~,

\.-. , ~ .•• ;· , i' ''.

<,'.·1,, ''·.

" ,,·_. ,, ...

, •/, •.:.,..···

,> ,;'

.. :~~-:~~::>·'::. ."·7~ '·,'::;·.~~~

' ",'•

,, ·. ·~. -~):· ..

. )"

'

. .- . ·.:'."/_

,

• /

"" $ ~-

~ ~

->-

vO ~ u z

' ~ c >--

i r l

l2JG 1100 iCJO 9('0 8JG 7GJ 6CJ 50:' 4CO 3G~I 2ca 100 D

~~G~ETOMETER P;OFILE DiSiA,';CE IN ~EET

COXSULTAtrrs [ t\ GEOLCGY At~:: ·3EOPHY.S ICS ll~E i

p,n,:-:;: 5/S/75 FI LE NO: K5-.:JZ4S- :·:l ! R..!i.CT 441 D

f ?'H,-f Q %.--_-)I .-IN A

,

EAST

=

!-

DI STMKE Iii FEE~

I re:· .. :~.c_::r. .11:iD .~ssJ:IA~Es t CC~SULTANTS IN GEO~OGY A~~ GEOPHYSl~S :SEISMIC l [i'iE

D-A7S: 5/ 'C/ 75 F'l'!...E !~O: KS-C'24~-Ml TR.ll,C"i ~4 l 0

I

; I'

4G

2:J

iif~~§:t~~0IBt-?~1.~~ttt~~. D so lOJ iSO L'CiJ 2S'.) 3CO ';:iO ~co ~5'.l 5GO 55,j

i '

- ,

/

BUP.Kl.AND AND ASSCC !ATES D I STANCE IN FEET

c.o~~SL1LTAN"7S n~ GEC-LOGY A~D G:::O?HYSICS

cAST

MA&~~!OHETER PRCFIL£

L r:..:E 1

---. .

• ,

,i

DISTMCE IN Fi::ET

EAST +~~ ·-·-·-·_;_~_. _._-; -- . --1--r.

BURKL.A\J MID /1S SJC rn TES

CC't\SULT ANTS lN GE0LGGY At~D GECPHYS ICS

Dt..TE ~ 5/8/7 5 F ! LE NO~ K5-:J2.:.S-M1

' .;_.-:_ -- I '~

MAG~ETDMETZR PRCFILE l ~NE 2

r::::..r.r .;.475

>-

- -/

-·--·-· ~ .

[I

,

t--:

·~ : I, I

DI ST..l.N C~ IN FEET

I , ' :~

200

11 '' '.' . I· i I , ! · ·--· --· _-_! · .. -~.:.-+-:::

-+ ··-

250 3CO 350 4CO 438

BURKLUJlD A:·!J ,LI,SSCClf',_"TES

CONSULTANTS I~l G~OLOGV AND GCOPHY-SICS

5/ '3. { i' 5 FILE NO: Ki-CZ~•-Ml

Et.ST

500 55G

TIME-DISTA~CE CURVE

SEIS~'.IC L 11'\E

•

260

t-

0

·-, •

;

EAST

EU'KlJ,\J MID ASSOC !.'.TES T:HE-O~STAKCE CUR~E

SC:ISMIC lIH.E 2

DtTE: 5/S/75