UNITED STATESDEPARTMENT OF THE INTERIOR

GEOLOGICAL SURVEY

GEOLOGIC DESCRIPTIONOF

SELECTED STRONG-MOTION ACCELEROGRAPH SITES

PART IV

by B. L. Silverstein

OPEN FILE REPORT No. 80-473

The report is preliminary and has notbeen edited or reviewed for conformity with

Geological Survey standards and nomenclature,

Prepared on behalf of theNational Science Foundation

Grant CA-114

Preface

This is one in a series of reports that summarizes geologic and engineering

data for selected strong-motion asccelrograph stations in the western

hemisphere.

Contents

Preface

Contents

Introduction

Geology Summary Sheets

Page

i

ii

1

References

Table 1

Figure 1

Appendix A

Appendix B

Station No.

5028

117

412

5165

1068

1136

1071

1118

1073

1127

1168

1115

3500

3501

3507

State

California

Instrument Site

El Centre, Sta. 7

El Centre, Sta. 9

" El Centre, Sta. 10

" El Centre, Differential Array

" San Francisco B of A

11 " " BART Vent Shaft

11 " " Beth. Pac. Bldg.

11 " " Eastman Kodak

11 " " Federal Bldg.

" " " Fireman's Fund

" " Pac. T. & T.

" " " Shell Bldg.

Managua, Nicaragua Banco Central

" ESSO Refinery

" " Intercontinental Hotel

Alphabetized Geologic Code

Lithologic Symbols

Combined Index of Parts I - IV

Explanation of Geologic Code

2

4

5

6

7

9

10

11

12

13

14

15

16

18

19

20

21

22

23

26

Introduction

This report is intended to serve as a convenient compilation of geologic

and engineering data for those who interpret strong-motion accelerograph

records. The data are taken from unpublished information on file with the

Seismic Engineering Branch and published reports such as Duke and Leeds, 1962;

Woodward Lundgrun Assoc., 1963; and Shannon and Wilson and Agbabian Assoc.,

1976.

If data are available from more than one source, the information given is

the most complete or up-to-date. The date of the coring is included when

available. The first page, of the two page summary for each site contains a

brief narrative of local or site geology, a location map, plus the station

name, number and coordinates as taken from Open-File Report No. 77-374. Where

the first page is used to describe more than one site, coordinates are listed

on the bottom of the second page.

The second page contains a graphic representation of the geology, and

where available, density (wet or dry indicated if known) and P- and S-wave

data. The lithologic symbols are taken from Figure 1.

The log, in most cases, is taken from actual core samples at the site.

Indication is given when the log is not directly at the site or the geologic

information is taken from sources other than cores, e.g. geologic cross

section.

The code on the bottom of the second page is a geologic summary for use in

a computer data bank. The reader is referred to Appendix II and Open-File

Report No. 79-289 for further information.

The term "generalized" indicates that a geologic core was not the source

of information and that the rock's actual sequence, thickness, and depth are

not known.

1

Stitton No. Static V«11ev

N, s.so'- U

SITE DESCRIPTION

This site is located on Quaternary alluvium and Tertiary aediaentary

rocks of the laperial Valley in aouthem California. The »axijnuni depth of

these deposits is believed to be about 6 to.. (Biehler and others,1964)

IMPERIAL

1 to, EL CENTRODifferentia

Array

N

A• N012

fW013

ituico

(from Forcclla and Katthitsca, 1979)

CO

ise 0)

3 0) n>

d y M »•*

vO to

is

* *

^

o

m

m

8f«

M f *

fi

i t!

I I

,1S

B

SS

m !

t•

II p s

fr O S1 5

3 J •4 • f

10/71 Jtotion IP. 117

l*pt*-^->A«MHV

ntt+ri

-10

-10

-30

-40

-50

-60

-70

f»fei»m/

Sc

f^itop*•aa

122

175

213

251

305

ie page 2

&*•***§/***

I.S41.511.57 ,1.51

1.51

1.491.511.36

1.51

,

1.57

1.55

1.52

1.62

1.47

fDtTlV** /

fee

?£?V=3£;S^JV-^^e«L"^ S."V«S

^.Vr"?• .•• .;••!••»••.•••..; •* » • _ • - •• • •• • *• V V •— 'SUSTfa.:. ^T'r^ -1;**»K. »«* ̂ w

-"^^--^^frTfr?.•.»// »•..••:.;%:.>.«• */i.*'*• • •• '*.» ,*.•/•' »••%•• •;/;>• • * ** • • • • . *, • ••.• •'••*•t • • «.• • • • • • *

Sif^^r - /P r^-^• •• ''; •'.'

•» • • •»•,'. •'••/ %•-••/•'.

55faK»>Xv-^PtJE&S-

L^vf-ii^rr-i-^

rir^r^•• '. •.*.••.• •*.'

fit* feeZe^v

Silty city vitb ace. lenstt Of•11 ty fiae aa&d.

Alternating layer* of allty clay, •11 ty fine aa&d, a&d aa&dya lit.

Silty fine aa&d with occ. le&aet •f ailty clay.

Silty clay with occ. layers ofaandy, clayey ailt.

Silty flee aand

Silty clay

Silty fi&e aa&d

k/75

Shannon & Wilson & Agbabian, 1976

Coordinates 32.79 N 115.55 W

gUNHAXJ Of STRONG-MOTION SITES

Bst«

Pepthm«ttrf

-1

-2

-3

-A

-5

-6

10/79 ft

F-fcfcvr*/<

S<

zti^n Jte. A

^-VjVf!•<?

>e page 2

12 f

Pmtttygforr?

tctum EI

tei

i3*P --^••*7^-» -w^ ^f

^V^"

<~ ^"~'Jr^.

•» ^» *•• *» ^» «

^^ ^* ^^» ^Hk MVi

^r^i"""^2L

— — •-»"tlr^?*^i ^J"-.. — '— «-v— ra:aW"-S.^^ r> •— '--

-*» — » •

pentror Sta. 10 r Conn. Hospital

5tt* C*OlO£V 1

Top soil

Clay

Sandy clay

1962

Hansen, W.R.,6, others, 1973 J

Coordinates 32.78 M 115.5?W ALV:AL6:AL

GEOLOGIC SUNHARI 0? STX019G-MOTJO* SITES

Dot* jp/79 Station Bo. 5165 Station E C Differential Array Doewppd Rd.

T-epth

-10

-20

-30

P-Uavc S-Vavem/**e

S<ee page 2

Penalty |££

• »«r.; •>-.** r

l-XrJTr.• ii 9-mu^ff «^«_

- "-"- A^fO -*JyC^^-''

Li^rrr:

•5^^;/.!/<v.'A/«.' : :'•S"^» ̂ 2.~

"SSS;^'

M^ ̂ ̂ *^ ^^fttT^T~»

Bite Geologv

Silty clay loam

Clay

Laminations of fine, sand, sandy loam, 6 silty clay loam

Clay

Lens of silty clay loam

Clay

Laminations of sandy loam and silty clay loam

Clay

Silty clay loam

Sand Clay

Silty clay loam & sandy loam Sand

Silty loam

Clay

Silty clay loam Clay Laminations of silty clay loam,

and silty loam

ClaySand

1946 >00 in northeast of site

lansen, W.R. , and others, 1973

Coordinates 32.80 N 115.54 V ALV:AL35:AL

SUtlon No.uiAftSUtlon San Francisco, Bank of America, 555 California

Coordinates 37.79 N. 122.40 W

SITE DESCRIPTION

The geology of the San Francisco North quadrangle consists of two distinct

rock types: 1) the Jurassic to Cretaceous Franciscan assemblage, which is

about 80% graywacke sandstone, 10% shale and siltstone, and the remaining

10% consisting of mafic volcanics, radiolarian chert, conglomerate, lime­

stone and glaucophane schist and 2) Quaternary eolian and alluvial deposits

(Schlocker, 197A)

ltut,r> ,r« , *.. „... ,..„ ̂ r g- -^y .>>K'V % %-tf^^te>ra3f¥S^r b«' »±{.-. v^r*!X.r ̂ m i^v' \ \., i-^r <

LOCATION AND TOPOGRAPHY SAN FRANCISCO NORTHEAST SITES

OfOLOGIC gUWARI 0? STXQ19G-MOTI019 SITES

Depth

—10

-20

-30

-40

i

P-Vave S-Veofm/,,e

&R 91

ften»tty

1.91

1.761.78

1.81

1.96

1.78

1.78

1.72

1.70

1.96

1.75

1.621.60

1.68

1.67

I B / .64

1.91

1.99

(Dry)

.T.ji -J ..•*»'

• *-.• • ' • •_ . £, f^r ..' . »

* • * / ' '

~r. *-.*;.* ' * -"^ '"» • •* » *• » « * •. . • «« » * •'••'•"•';

• ','•• . * *';..'•',

•/•.*'/;•••• « « • «' •'.*• •'. *

* « * *

* * * 9 *

^^ * "Xj *

*? Tv3^.** •**i-' r^. '^"* TT___-f *^^ ^^^

vJS"^x^.H^fC^^*^^ j^y*^~i _ •"* *^^^** ^^ —^ "<^-^** ^* * ^

^_^ *^^ iw^ «^^

-rr^r^^1- — - — — —

"ZH^ ̂ •••^ — •

SS*."•*•*•* *{ \-\~*C'*•*.* ^ *

^— JT^«i— » ••v ̂ * •» **.**- «=- ^-r-'—r-

»*r* * * * *

Sitt Geoloffu 1

Iriayev sand . . f -nA- t rlnil\ — •• — rf — --• ——— • • banay clayClayey sand

Sand with silt and clay

Sand

Silty sand with rock fragments

Sand with clay and silt

Sand with clay, silt and gravellenses

Clay with rock fragments gradingto highly fractured shale

Gouge of highly fractured shale

Sandstone-fractured

Shale-highly fractured

Silty sandstone-fracturedShale-highly fractured Silty sandstone-fractured

12/17/64

Hansen, W.R. , & others, 1973

ALV;AL33:SHF+SSF46

8

m/**o

10

20

*&;=&•t/9*-

tit* G*olt>ffy

clay

clayBT ~ ~" 1^1 • • j *•*•/Fi'L'^tfrKand with ahell fragments•*' -^ —'^r

Lty clay with shell fragments

>ilty clay

clay

30 1.64

-* <*^ T^'.V/^ilty to clayey aand

-lZl^il:>;:.:. '/I'.' '•';! •land and gravel

40

See page 7

CDry)

Coordinates 37.80Ji ,122.39 W

cUy

/28/70

Hansen, W.R., & others, 1973^

SUWARI OP STRONG-MOTION

Date 1/8Q Station I«.JJ?71 Station <:«« tvfl t^-t gr^~Beth. Par. Bldt^lfln r*

pgpth P-Kxve S-Hiv*mettrf

— 10 1

- 20

— 30

AO

m/eec

I>ee page 7

Density f/em*

log

*'/''*' ' •' ' V '•• '£.-:v :',<*':.'«''/*•*'. '• 4 • .

4r - *. ——

H^Lif'-- ^-^^"V^---^"£"j- "^ "HL!

^rJfjrc— •»* -— •rliS-«^ — — -^-i?^±' '^ •-;/. » '. .»' ••• ,'.'|'*.*'•'*f-,-.»% » .•• » »

~ ~^_ «^-^ * j*

5ttr Geology

and and gravel with- concrete & brick rubble and wood debris.

ilty clay with seashell fragments

Jandy loam

Clay

S^5tL.'^'T'C Sandy clay cr."=-''^

3/3/57

*same as Insurance Sec. Bldg..

Hansen, W.R., & others, 1973

f

Coordinates 37.79 K 122.40 W ALV:AL3010

CBOLOGIC gUMHAJW OF STRONG-NOTION SITES

Station Ho. 1118 Station San Francisco.Eastman Kodak,3250 Van Ness

^cpfh P-Vave S-Uave Penalty-tettr§ m/9tc

-10

- 20

-30

-40

t/enl

•

See page 7

*?~"^

"2x0

Iff• • * . • »',•:•> .. • ;'•/'•//•*' /'* f '/

'* *^*' *

'&/>'*k */ *'/' V' ; •'*•»

• v ' • •

r-Lr^J"^

r^fTTf?

5ite Geolojjv

Loose fill and rubble material, firmer with depth

Sand with trace of clay

Clay with rock and decomposed rock

Franciscan shale and sandstone with clay

Jan., 1957

Hansen, W.R. , & others, 1973

Coordinates 37.81 N 122.42 W ALV:AL32:SH+SS33:SH+SS

11

CBOLQGIC SUMHARJ OF STRONG-MOTION SITES

Patt 12/79 Station to. 1073 Station S.F. Federal Bldg. 450 Golden Gate

Xpth P-Vave $-Uave flrnn'ty~ietert tn/iec g/cm^

- 10

- 70

- 30

- 40

See page 7

log

•':'.'•'•'•.',' t • ' •;'•' • '*"' ''. •/v.'V/';y;^: ;*/*' ' '.'• *•'•^i^C. -^..Xl T"^^• * • ' 1

'*,»•*• *»• '*. *'r.*'V v•**• . ** *» *.* *

.'••.;.V? ; i; :/1 . < ' » • » •/' •/* *;*-•. * »''•'•*'. '. 'V

r • • • .'• • '"•,-"/'.•',

'.•''•'V'^r* •.'viT'*i-'^c.V

£&&* •'** f * ** *» ,

Site Geoloou

Sand

Silty Sand

Sand

Lense of clayey sand

Silty sand

Sand

8/4/58

Hansen, W.R. , & others, 1973

Coordinates 37.78 K 122.42 V ALV:AL38:AL

12

gUWAXI Of ST*OJ9G-9iOTTON SJ7TS

Dat*__l/fiIL_ 9tatiffn IP. Jill

rpt* »-tt™* 8-V*>* S£"1$LmettrB

F^amans Fund 3333 Calir

Sit*

Y>'*•'•.''-^ SandSandy loam ^=r ^---g'^ Clay loam'•'/• : f' ; -' Sandy loam with sandstone frag. .. * • • • • * • • • '

[I:".::*«;;" Shale and »andstone(fractured)

A/26/5A

10

See page 7

Coordinates 37.79 K 122.45 W

Hansen, W.R., & others, 1973^

ALV:AU:SHF+SSF7

13

GEOLOGIC SUNHARJ OF STXONG-MOTION SITIS

Date i/ao Steticm Ho. 1168 Station San Francisco Eac. T&T 555 Pine

fcpth-*ter.

—10

—20

F-Vavem/

Si

S-Vav*•<c

»e page 7

Dtniity-§/***

1.75

1 7R* / oon

2.002.122.20

2.072 9ft. f.o

IPS

*"•%.£*

V »

f ^5 ^ ' * "•'

^-^JX^_ — — —— ——— —— -!

^-^~ —— -

"^ ~~" " — ;ZH

v>v*.\:.-i

5itr Gtoloav

Silty clay with bricks & rockfrags.

Sand with some clay, bricks &rock frags.

Clav

Shale- weathered and altered

Shale and sandstone

Sandstone

12/9/57

Hansen, W.R. , & others, 1973

•Coordinates 37.79 N 122.40 W ALV:AL5:SH+SS13

14

GEOLOGIC SUMHAN OF STRONG-MOTION SITES

Date j/an Station Ho. 1115 Station San Francisco Shell Building

Zeptn

— 10

- 20

-30

- 40

P-Vave $- Verve flentttv«/

S<

it?

»e page 7

.f/*# toe

1 • i * • *.•••'•'• '"V,

• * * t » • '

'•• ''•'•/!'

' X ' •»• • • * .• > . » / '

a ^ <. *L, fr*f ^

S^i^i-Y.^XIV"* "7 T,"1*

* « . » *y* * xr*^ * * -L * *_ •*"•/ ,»*>

JK~I^Si

5tte Geoloav

Sand

Sandy clay

Sand

Sandy clay

Clay

Sandy clay

June, 1929

Hansen, W.R., & others, 1973

Coordinates 37.79 N 122.40 V

15 ALV:AL40:AL

Station Ho. 3500

Coordinate! 12.15

Station Managua. Banco Central

»t B6.27 V

(Nicaragua1

Managua is located on several thousand feet of deposits consisting of

thick units formed by volcanic ash-laden nud flows and thinner Stream-

deposited beds. This alluvium is interspersed with layers of volcanic ash,

cinder, and pumice.(Valera, 1973)

LAKE WANAGJA

LAGUNA DE ASOSOSCA

LAGJNA TISCAPA

Intercontinental Hotel

I CM

(EERI Reconnaissance Report. 1973)

16

'LOGIC1 MMVA/fJ \M

flatten*. 3500

fet fCt^ ft^pTffffvmctcri m/**c §/&*?

- 10

1.70

1.50

1.52

(vet)

V/jV/%/ 1r ft » *

» • ^

*« V*o •*°>* *I"/ »fl0 4*»°

nV**'•• *•**'*•*

^T'^:':::z••-*«'«'»**

$?*?)^.'•^ 'il't V•» *• **».'^ */* * * • **

V ••'.•!/

-* J^ '* ? ̂ & *

*i '" *• "• * •t'

Band (ooartc, denae and partially cemcr.tcC)

Volcanic tuff afclcrcrete

Sand (ooarae and dense)

Silt (ccrenteo)

Pucice

Clayey tilty aend (verj- dense)

Silty und (desfte)

Alternating layers of calc»ccuscoLelo&erate and dense cemented gravelly aand

June. 1962

7alera, 1973

17

*****

Stratified tandrtone

Coordinates 12.1A « 86.27 W18

GEOLOGIC SUMMARY OF STRONG-MOTION SITES

Zfet* 9/T9 Station 9o. 3501 Station Managua. EST-C Refinery (Wiceraeue)

Depth

- 10

- 20

P-Vave S-Vcev*m/**c

Pcnittv g/cm*

J!

Se:e page 16

log

^SiTr

^^

^ ' * • -f^

:^|••^r/.-v

8* *.•»'.*

» »^ . <.-^L'

• * "^

"^ (£>"«. ». K •

• • •' • * * ';!p;.?"»: <>;V.* '•*•*•* *. * *y,c.-'-/*' '•*". • '.*

:*V'^'

5ttr Otology

Sandy tilt

Silty sand vith gravel

Silt vith grave]

Sandy ailt vith layers of silty •and and occasionel gravel

Silty sand vitL froze grevel

Fine to coarse eer.d vith ^pr«vel

Valera, 1973

Coordinates 12.14 N 86.32 W ALV:

19

References

Biehler, S., Kovach, R. L., and Alien, C. R.; 1964, Geophysical Framework and Northern End of Gulf of California Structural Province; A.A.P.G., Vol. 3, p. 126-143.

Converse, April; 1978, Strong-Motion Information Retrieval System User's Manual; U.S.G.S. Open-File Report No. 79-289.

E.E.R.I. Reconnaissance Report; 1973- Managua, Nicaragua Earthquake of. December 23, 1972.

Hanserr, W. R., Weiss, R. B., Idress, I. M., and Cluff, L. S.; 1973, Geotechnical Data Compilation for Selected Strong-Motion Sites in California; Woodward-Lundgren Assoc.

Porcella, R. L., and Matthiesen, R. B.; 1979, Preliminary Summary of the U.S. Geological Survey Strong-Motion Records from the October 15, 1979 Imperial Valley Earthquake; U.S. Geological Survey Open-File Report 79-1654.

Schlocker, J.; 1974, Geology of San Francisco North Quadrangle; Geological Survey Professional Paper 782.

Seismic Engineering Branch; 1976, Western Hemisphere Strong-MotionAccelerograph Station List, 1976; U.S.G.S. Open-File Report No. 77-374.

Shannon and Wilson, Inc. and Agbabian Assoc.; 1976, Geotechnical and Strong-Motion Earthquake Data from U.S. Accelerograph Stations; Nureg-0029, Vol. I.

Vatera, J. E.; 1973, Soil Conditions and Local Soil Effects During the Managua Earthquake of December 23, 1972; Earthquake Engineering Research Institute Conference Proceedings, Vol. I.

20

TABLE 1

ALPHABETIZED GEOLOGIC CODE

ROCK TYPES

AC Coarse AlluviumAF Artificial FillAG AgglomerateAL AlluviumAM AmphiboliteAN AndesiteBA BasaltBR BrecciaCG ConglomerateCH ChertCI Combination IgneousCM Combination MetamorphicsCR Combination Rock TypesCS Combination SedimentaryCY ClaystoneDI DioriteDK Dikes or SillsDO DolomiteFR Franciscan RocksGB GabbroGD GranodioriteGN GneissGO GougeGR GraniteGS GreenstoneHF HornsfelLF Lava FlowsLS LimestoneMR MarbleMS MudstoneMZ MonzoniteOB ObsidianPH PhyllitePU PumiceQM Quartz MonzoniteQZ QuartziteRY RhyoliteSC SchistSH ShaleSI SiltstoneSL SlateSP SerpentiniteSS SandstoneSY SyeniteTF TuffVA Volcanic Ash

CLASS CODE

ALV AlluviumIGN Igneous RockMET Metamorphic RockMIX Mixture of Rock TypesSED Sedimentary Rock

EXPLANATORY SYMBOLS

C CementedD DeepF Fractured, Sheared, or JointedI InterbeddedK xlOOO (multiplier)L Layered or StratifiedM MassiveP PermafrostS SemiconsolidatedU UnconsolidatedV VeneerW Weathered or FriableX Crystalline Basement: Overlying+ And

Decimal

21

8UR

FIG

IAL

SED

IMEN

TAR

Y

ro

ro

MET

AM

OR

PHIG

IGN

EOU

S A

ND

VEI

N M

ATT

ER

IJT

HO

LO

OIC

SY

MB

OL

S U

SE

D I

N

tmU

JCT

UR

B A

ND

CO

LU

MN

AR

SE

CT

ION

S T

O R

KP

RE

8EN

T D

IFF

ER

EN

T K

IND

S O

F R

OC

K

Appendix A

Combined Index of Parts I - IV

Station No State

2305 Arizona

1001 • California

1002/1194

1003

1161

1007

1180

1121

1219

1008

1120

1013-16

5028

5117

5412

5165

1023

1024

1188

1229

1028

638

1222

Instrument Site

Phoenix V.A. Hospital

APEEL Array Sta. 1

,, 2A

n n n 6

n n n q

n n n in

ii ii ii 1 r

II II II pp

ii ii ii or

Bishop

Buena Vista Pumping Plant

Cholame-Shandon Stations

El Centre Sta. 7

El Centre Sta. 9

El Centre Sta. 10

El Centre, Differential Array

Ferndale, Old City Hall

Foster City, Audubon School

Fremont, 3909 Stevenson

Fresno V.A. Hospital

Hollister City Hall

Los Angeles V. A. Hospital, Brentwood

Menlo Park, 1330 University Drive

Part

I

inIII

III

III

III

III

III

III

II

II

II

IV

IV

IV

IV

I

III

III

II

III

I

II

Page

3

6

8

10

12

14

16

18

20

3

5

7

2

4

5

6

7

24

26

12

28

9

14

23

1215 " Mt. Diablo Summit Building II 16

1046 " Newville, Flood Farm II 18

1140 " Oroville Dam 111

1051 " Oroville, Seismograph Station I 13%

1191/1212 " Palo Alto Sq. Nos. 1 and 2 III 28

1054 " Pine Flat Dam II 20

639 " San Diego V.A. Hospital II 22

1068 " San Francisco, B of A IV 7

1136 " San Francisco, BART Vent Shaft IV 9

1071 " San Francisco, Beth. Pac. Bldg. IV 10

1118 " San Francisco, Eastman Kodak IV 11

1073 " San Francisco, Federal Bldg. IV 12

1127 " San Francisco, Firemen's Fund IV 13

1117 " San Francisco, Golden Gate Park I 15

1168 " San Francisco, Pac. T & T IV 14

1228 " San Francisco, Randall Museum I 17

1115 " San Francisco, Shell Bldg. IV 15

1225 " San Francisco, V.A. Hospital I 19

1098 " Terminus Dam II 24

2201 Montana Butte, Metallurgy Building I 21

2008 Nevada Reno, V.A. Hospital I 23

2605 New York Albany, V.A. Hospital I 25

2206 Utah Flaming Gorge, Seismograph Station I 27

2203 " Logan, Admin. Bldg., USU I 29

2210 " Salt Lake City, V.A. Hospital I 31

24

2130

2101

2102

2106

2124

350U

3501

3507

Washington American Lake V.A. Hospital II 26

11 "Olympia, Highway Test Laboratory I 33

11 Seattle Federal Building II 29

Seattle, Pier 20 I 35

Walla Walla, V.A. Hospital II 31

Managua, Nicaragua Banco Central IV 16

" " Esso Refinery IV 18

Intercontinental Hotel IV 19

25

APPENDIX B

Explanation of Geologic Code

The symbols and their meanings are listed in Table 1. The code's first

characters (class code) describe the surface materials without regard to depth.«W«MiMM«*MMB-». %

Specific site lithology is indicated after the first three letter class code by

group's of two letter abbreviations (rock types) which may have a third letter

(explanatory symbol) that describes a physical characteristic, e.g. SH is shale and

SHF is fractured, sheared, or jointed shales.

A number after the rock type is the depth to the base of the unit, e.g. AL914

means alluvium to a depth of 914 meters. Except for the first colon after the three

letter code, which serves as a separator, the colon indicates "overlying", e.g.

AL914:CS1067 means alluvium to 914 meters overlying a combination of sedimentary

rocks that extend to a depth of 1067 meters. The letter K after a number is 1000

times multiplier, e.g. 4K means 4000 meters. A lack of number means the depth of

the material is not known. A standard geological abbreviation is not used.

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