Lake AI manor

Lassen

Peak

MARCH 1991

CALIFORNIA

GEOLOGY

A PUBLICATION Of'THEDEPARTMENT OF CONSERVATIONDIVISION OF MINES AND GEOLOGY

Slale 01 CaliIomia PETE WILSONGo~

The~~ DOUGLAS P WHEELERS6crerwy for Resooroos

~ or eon-vauon EDWARD G HEIOIGo,r9Ctor

JAMES F, DAVIS51818 GB%gIst

CALIFORNIA GEOLOGY stall

In This Issue ICALL FOA PAPEAS 50ACTIVE FAULTS NORTH OF LASSEN VOLCANIC NATIONAL PARK 51PRODUCTS OF THE ALQUIST-PRIOLO

FAULT EVALUATION AND ZONING PROJECT . 59PRELIMINARY REVIEW MAPS OF PROPOSED

ALQUIST-PRIOLO SPECIAL STUDIES ZONES . 63SIGNIFICANCE OF CALIFORNIA'S MINING INDUSTRY 64BOOK REVIEWS 69MAIL ORDER FORM 69MEMORIAL-QUINTIN ALBERT AUNE 70MINERAL5-A PAGE FOA TEACHEAS 71ANNOUNCEMENTS 72

SMIP91 SEMINAR 72FOURTH INTERNATIONAL CONFEAENCE ON SEISMIC ZONATION 72

Prlntedc ~ 01 GoJnMaI serw::.0Ill0I 01 Slatll PrInting

T&ehrllcal Editor,AssIstant Editor:GraphICS and Deslgn:Publications Sllpervlsor:

Don DuprasLena Tabllio

Louise HucllabyJeIfTamben

Cover: High al1itude panorama looking SOIJth along the prominentscarps 01 the Hat Creek faullioward Lassen Peak. This fault dis·places lale Quaternary volcanic rod<s and was recently investigated10 determine il it Is active. An article about this faull study starts onpage 51. U.S. Ai' Force photo, 7968, #064L 009.

~~ ,.'8 Ninth Street Room 13041s.cr_.CAfl5lIl.

(T"- 816-«5-18251

I'uIlloc:auoN ancl1l'llom'lliorl Olloce"680 lleta.ol DrI\Ie. Sacr_. CA 95811-0131PIIIllo:: irlIoITNlIon 816445-5711;

to. AIlgeIM 0Ib 107South~' Room 1065l~~. CA 90012-"02(1......... 21U20-3560)

I'IHMnl HiI ()Il;ce 380 Ci'nc 0nYt. s..- 100P\eat.anI Hill, CA g.t523-1991(Tllep/IOr'It a15-60&6·!i920)

CAliFORNIA GEOlOGY (ISSN 0026 4(55) •~monlhIy by the I.>epatImenI 01 eo.-v,lIOn,~ III MnMancl '**'or, The RaQorIb 0110:.. ~ ~ 1721·2OItl StreM.s.a_. CA 951111 5ec:onlI da..~ II J*d IIIsaer_ CA. PoelmQle< s.nd 1Oddt.- chII...... 10CALIFORNIA GEOlOGY (USPS 350 8010), Sol 2980. 5ac<a·.......,. CA 95812-2980

Aepcwu; COIlC*'IWIlI OH-. 01 Mit\M. and G8<*Igy P'0flICIS..-.cl... ancl __ w...~ ID Ihf UIltl liDenc:es InCaIilorr.- ..~ on '" II'IIIgaZlIW ContribuIec:l artldea.~_lMms.ancl~~lII'II'IClUI'I<

-~-

Call for Papers

The Second Conference on Earthquake Hazards in theeastern San Francisco Bay area will be held March 25-28,1992 in Hayward. California. Contributed papers are invitedand must touch specifically on some aspect of earthquakehazard in the eastern part of the San Francisco Bay region.although studies relevant to the entire region will be consid­ered. Preliminary abstracts are due by June I. 1991 to beconsidered for inclusion in the conference. Papers. not to ex­ceed eight published pages. are due by September 1. 1991.For further information contact: Dr. Sue Ellen Hirschfeld.Department of Geological Sciences. California State Univer­sity. Hayward. CA 94542. telephone: (415) 881-3486.x

TIE CONCl.USIONS AND OPINIONS EXPRESSED INARTICLES ARE SOl.ElY THOSE OF THE A,UTHOAS ANOARE NOT NECESSARILY ENOClA$EO BY THE DEPARTMENT OF CONSERVATION

Co"..pondanta ahould bl add,nsl'd 10 EdOlO,CAliFORNIA QEOI.OOY. 660 BerCUl 0nwI. 5acf_. CA9581.·0131

Sublcripllonl. $10.00 pel V-. Single QI;lIlIN $1.25..,;11Send~ ordefs and c:hange 01 __ onIon1>MIonIOCAlIFOAHIA GEOI.OOY. P O. Bolt 2980. 5acf_.CAll5e12-2lllIO

March 1991Nolume 44/Number 3

CGEOA 44 (3) 49-72 (1991)

Note to Subscribers

CAUFORNIA GEOLOGY isapproximately six weeks behindschedule. Many subscribers, con­cerned by the lag in receivingtheir monthly issues. wonder Iftheir subscriptions have lapsedor have not been renewed. Thisis not the case. We are makingevery effort to meet productiondeadlines and appreciate theunderstanding and patience ofour subscribers ... editor.x

Correction

In the! third paragraph on page36 in the February issue, Illinoiantime was incorrectly defined bythe editor. Based on the bestoxygen-isotope correlations avail­able, the authors define lllinoiantime to have occurred betweenapproxirnately'130,000 yearsago and 190,000 years ago.X"

50 CALIFORNIA GEOlOGY MARCH 1991

Active Faults North of Lassen VolcanicNational Park, Northern California

By

C.J. WILLS, GeologistDivision of Mines and Geology

INTRODUCTION

Bolded terms ale In Glo$sary on page 58.

Along the approximate boundarybetween the Cascade Range and theModoc Plateau. a series of faults haveformed spectacular. high. steep scarpsin the volcanic bedrock. The bedrock

of this area is composed oflate Tertiary and Quaternaryvolcanic and sedimentary de­posits. Widespread. nearlyflat-lying basalt flows of theModoc Plateau underlie muchof the area. Lassen Peak, alarge dacite dome last activein 1915. and Medicine Lakevolcano. a large shieldvolcano that has also beenactive in recent times. arefound at the south and northends of the fault zone. Bothactive volcanoes are consid­ered part of the CascadeRange. although the Medi­

cine Lake volcano lies east of the mainCascades. Smaller volcanic centers arescattered along the fault zone betweenthese two major volcanic centers. TheFall River Valley. a basin filled withQuaternary alluvium and lake deposits.occupies the center of the zone.

Normal faulting between two ofnorthern California's most active volca­noes implies thaI extension of the crustmay have provided a path for magmato reach the surface. The clustering oflate Pleistocene volcanic vents alongthe fault zone further supports this sug­gestion (Figure 2). In the southern halfof the region. Guffanli and others(1989) found that Pleistocene vokanicvents are scallered over a broad area.but all of Ihe 52 vents younger than25.000 years are at Lassen Peak or inthe zone of normal faults to the north.

GEOLOGIC SETIING

Figure I. Ir'lde~ map 01 geOlogic provinces01 northern California and locations of ma­jor volcanoes In the Cascade Range.

Northeastern California is underlainby Tertiary and Quaternary volcanicrocks. These rocks have formed twodistinct geologic-geomorphic provinces(Jenkins. 1938) (Figure ll. To the westis the Cascade Range. a north-southtrending range of aclive volcanoes thatextends southward through Washingtonand Oregon into northern California.East of the Cascades is lhe Modoc Pla­teau. a high (4.000 10 6.000 feet eleva­tion) series of plateaus and low moun­tains. separated by broad valleys. TheModoc Plateau is mostly underlain byflat-lying basalt news of late Tertiary toPleistocene age (mostly between 5and 10 million years old).

Lassen Volcanic National Park (Figure2). The following descriptions of thesefaults indicate that the faults are activeand pose an earthquake hazard to partsof northern California.

ifu),:.r-'=1:t:;~-._.~, SISlOYOO ~ ~

-'.\ '0 j: '1,, ~ «', "v" MCOOC

i".J . """~' J "'1cl' MODOC <j .(LASSE ~\I ~ PLATEA ,~• /' PK.t: 7 I>

HlN-llOUlTI • - ........ ---..,...;: w

. TflHTY"':"" Area of'-J /~'~o' z- -1.._) ....:::l'U'.2~ •-' - -~ " /'U.W.S", :------l-l

Faults in the Cascade Range.Modoc Plateau, and Basin andRange geologic provinces (Rg­ure 1) displace volcanic bedrockof Iale Tertiary and Quaternary age.Many of these faults have formed spec­tacular high. steep scarps in volcanicbedrock. The steepness of the scarp isusually a clue to whether a fault has dis­placed the ground surface in Holocenetime. Hoo.vever. in the resistant vol­canic rocks of northeastern California.high. steep scarps may have stood. re­sisting erosion. for several tens or ewnhundreds of thousands of years. Thisinvestigation concentrated on details ofthe fault scarps and geologic depositson and adjacent to the faults to deter­mine if the faults are active.

The highest and some of the sharp­est fault scarps in northeastern Califor­nia are also the most easily accessible.The Hat Creek. McArthur. and manyother related faults are crossed by StateHighways 44 and 299 and the HatCreek fault is visible from Highway 89for over 10 miles in the region north of

Geologists of the Division of Minesand Geology's Faull Evaluation

Project have recently evaluated many ofthe faults in northeastern California forzoning under the Alquist-Priolo SpecialStudies Zones Act of 1972.This act requires the Stale Ge-ologist 10 zone for special stud-ies those faults thai are "suffi-ciently active and well definedas to constitute a potential haz-ard to structures from surfacefaulting or fault creep" (Hart.1990). Official Alquist-PrioloSpecial Studies Zones maps forthese faults will be issued onNovember 1. 1991.

CALIFORNIA GEOlOGY MARCH 1991 "

LASSEN VOLCANICNATIONAL PARK

The Hat Creek fault zone offsetslower Pleistocene basalt down to thewest along its entire length. Faultsalong the base of the Hat Creek Rimoffset the younger Hat Creek flow andflows from Cinder Butte (Figure 2).The fault zone shows a distinctive left·stepping pallem of faults with displace­ment decreasing on one strand as itincreases on the adjacent strand. Thisen echelon fault pattern suggests acomponent of right-lateral offset alongwith the normal offset.

FlQure 2. 5lmplilied geologIC map shoWInglaulls and young volcanIC fields and IIowsbetween Lassen Peak and MedlQne lake""","00

The system of faults between LassenPeak and Medicine Lake volcano form acomplex zone over 50 miles long andup 10 20 miles wide (Figure 2). Themajor faults within this zone. the HatCreek, McArthur. Pittville. and Mayfieklfaults are from 15 to 35 miles long. Allof the faults are normal faults and mosthave the west skIe down-dropped.Fault scarps are most prominent wherethey disptace Pliocene to early Pleisto­cene basalt. This is a result of millions01 years of accumulated fault offset andthe very resistant rock. These highsteep scarps are referred to locally as-Rims~ such as the Hat Creek Rim orthe Butte Creek Rim. Scarps are b.i.rer.but commonly sharper in late Pleisto­cene basalt t1oY.>s and lower still andmore gentle in alluvium.

Hat Creek Fault Zone

FAULTS

Two roads that cross the Hat CreekRim allow easy access to the fault.Highway 44. easl of Old Station .crosses lhe Hal Creek Rim along a

The Hat Creek fault zone follows theHat Creek Rim. a prominent west-fac­ing escarpment along the east side ofHat Creek Valley (FIgure 2). The es­carpment is about 25 miles long and up10 1.600 feet high. Diller (1908) firstrecognized it as a fault. Anderson(1940) produced the first detailed mapof faults along part of lhe Hat CreekRim in a study of the Hal Creek lavaflow.

Other faults

lale Pleistocene orHolocene vok:anicfield or flow

EXPLANATION

____ Active faultsO ediClne Lake·Caldera I

II

~i~

~i~III"'­!<eC"",

N

I• M....

CALIFORNIA GEOlOGY MARCH '991

Photo t. View south along the Hat Creek Rim Irom Bidwell Road. Note the Ilat bench01 Hat Creek basalt Justlelt 01 the center 01 pholo. This flow is equivalent 10 the flowthat underlies the valley 10 Ihe right. Photo by author.

sloping bench between two strands ofthe faull. Driving eastward over the HatCreek Rim is a good way to appreciatethe 900 feet of displacement along theHat Creek fault between the Hat CreekValley and the plateau to the east.

Another road north of Highway 44crosses the Hat Creek Rim near its high­est point and crosses one of the large,recent scarps in the Hat Creek basalt atits base. This road can be reached fromHighway 89 by following Doty Road toBidwell Road andBidwell Road tothe base of the es­carpment. BidwellRoad is paved tothe base of the HatCreek Rim andgraded dirt fromthere to the top.The road to thetop of the rim pro­vides views southdown the HatCreek Valley to­ward Lassen Peakas well as a vividimpression of thesteepness andheight of the faultscarp (Photo 1).

Where this road crosses the scarps atthe base of the Hat Creek Rim, thefault separates a bench composed offlat lying Hat Creek basalt on theupthrown side of the fault from theequivalent flows buried by alluvium onthe downthrown side (Photo 1). Totaloffset across the fault is at least 70 feet.The fault scarp is made up of a fissureand a block of basalt with its surfacedipping steeply toward the valley. AtBidwell Road the fissure is 15 to 25feet wide, up to 30 feet deep, and hasabout 3 feet of vertical displacementacross il. The block with the steeplydipping flow surface is broken by manysmaller fissures and locally reduced torubble. but foons the majority of thefault scarp.

Because this fault offsets the HatCreek basalt, the age of this basalt

VJOUId constrain the age of most recentfaulting. if it were accurately known.Unfortunately. the Row has not beendated by any quantitative means. An­derson (1940) considered the flow to bevery young based on the fresh flow fea­tures, lack of weathering of the basalt.and lack of vegetation except in areasof pumice accumulation. He estimatedits age to be about 2,000 years basedon the probable rate of downcutting ofthe channel of Hat Creek given its gra­dient. flow, and sediment load.

Muffler and Campbell (1980) as­signed a Holocene age to the Hat Creekflow but more recent work (Muffler andothers, 1989) has shown that the flowmust be older bc<ause it is overlain byglacial outwash of late Tioga age(11,000 to 15,000 years). Woodward­Clyde Consultants (1987) estimated theage of the Hat Creek flow to be aboutSO,OOO years. They based their esti­mate on the relatively poor preselVationof fine flow features and on the rela­tively thick vegetation cover. The mostrecent estimates place the age of theHat Creek basalt al about 15,000·40,000 years (Muffler and others. 1989)(Wills. 1990).

The amount of offset and the age ofthe offset unit provide an important wayof gauging the earthquake hazard of aspecific fault. Simply dividing the

amount of offset by the age of the unityields a slip rate, expressed in millime­ters per year. The Hal Creek fault hasdisplaced the Hat Creek basalt by about70 to 100 feet (20 to 30 meters) inroughly 20.000 10 30.000 years. yield­ing a slip rate of about 1 meterIthou­sand years or 1 mm/yr.

Slip rates are long-term averages ofIhe slip on a fault. Most faults move in­frequently. with each movement accom­panied by a large earthquake. A fault

with a 1 mm/yrslip rate mayhave ground-rup­turing earth­quakes every500 years. eachof which hasabout 1/2 meter(20 inches) dis­placement: every1.000 years.each with 1 me­ter (40 inches)displacement. orevery 2.000years. each with2 meters (81inches) displace­ment. An earth­quake with I me­ter (40 inches) ofdisplacement on anormal fault istypically about

magnitude 6.8 (Bonilla and others,1984). If earthquakes of this size occuron this fault only every 1,000 years,people may be lulled into the belief thatmajor earthquakes do not occur in thisarea. A slip rate of 1 mm/yr does indi­eate a signilicant seismic hazard, par­ticularly because we do not know whenthe last major earthquake in this areawas. or when the next one will be.

A further complication in resolvingthe activity of faulting along the HatCreek fault is that the prominent scarpsat the base of the Hat Creek Rim werenot originally thought to be fault scarpsat all, Finch (1933) and Anderson(1940) described these scarps as Mslumpscarps.M A Mslump scarpM lor the pre­ferred term Mlava subsidence scarpM

(Sharpe, 1938)1 forms when fluid lavapools against a hill or a fault scarp.

CALIFORNIA GEOlOGY MARCH 199\ "

MARCH 1991

~~

, "5:~

< -'(\

\~ #,

••

CALIFORNIA GEOLOGY..

If a crust fonns on the lava and thenthe fluid lava flows out from under thiscrust. a scarp will fonn at the edge ofthe lava pool. In the case of the HatCreek flow. lava may have poc>'ed inthe upper Hat Creek Valley against theHat Creek Rim fault scarps. then bro­ken through or flowed around an 0b­struction. draining the pool and fonninglava subsidence scarps along the base ofthe Hat Creek Rim.

Recent work by Woodward.QydeConsultants (WCe) (1987). Muffler and<>then (1989), Clynne and Muffle,(1989). and WiUs (1990) suggests thatthe scarps at the base of the Hat CreekRim are tectonic. no! lava subsidencescarps. WCC described evidence forrepeated tectonic rupture along thisfault since the Hat Creek lava flow wasdeposited. Muffler and others (1989)described several features of thesescarps that are consistent with faultscarps but not with lava subsidence

'''''I''·The scarps at the base of the Hat

Creek Rim are true fault scarps. ratherthan lava wbsKience scarps (Finch1933; Anderson. 1940) for four rea­sons. (I) A scarp profile with two dif­ferent ages of movement as describedby Woodward-Clyde Consultants (1987)could not have formed as a cooling fea·ture In a single volcanic flow. (2) Muf­fler and others (1989) note that thesescarps lack lava stalactites and oozeouts. which are common along lavasubsidence scarps. The lack of thesefeatures suggests that the lava hadcooled before the scarps fanned. (3)The lava exposed in the fissures nearBidwell Road did not fonn from a singledeep pool of lava. At this locationthree separate flows are exposed in thewall of a fissure Each flow had cooledas a horizontal sheet before the scarpwas formed. (4) Scarps of about the

.... Photo 2 High-attltude aenal photographof the Fal RIVer Valley and surroundingareas Fautl scarps appear as dark lineson thrs 1maQ9 Note especially the Ieft­stepplng en echebn scarps In late Plels·tocene baMIt along the McArthur laull$OUch of Fa! RIVer Valley U.S AN Forcephoto. 1968. «J64V 008

same height offset the Hat Creek flowand older flows from Cinder Bulte.

McArthur Fault Zone

The McArthur fault zone Is locatedeast of and parallel to the Hat Creekfault zone (Figure 2). It fonns a similaren echelon pattern of scarps. West­facing scarps up 10 500 feet high alongthe Butte Creek Rim mark the southernhalf of the zone where the fault dis­places early Pleistocene basalt TweS1reams that cross this scarp haveeroded canyons part of the waythrough the escarpmenl. Both S1reamshave Sleeper gradients just upstream ofthe fault, indicating that erosion hasnot been able to keep up with faultmovement. and suggesting that Ollselmay be continuing in the Holocene.

11le southernmost segment of theMcArthur fault offsets alluvium m ameadoYJ along Butte Creek. Becausethis meadow is only about 3 milesdolNnstream from the end morainesof Tioga-age glaciers. the alluviumis probably late TIOQlI outwash oryounger alluvium Ollset of this surfacestrongly suggests Holocene movementon this strand of the McArthur fault

Along the McArthur fault near BaldMountain. scarps are broader. taluscovered. and incised by minor drain­ages (Agure 2. Photo 2). The erosion­ally degraded appearance of the scarpssuggests that this fault segment Is notHolocene active.

North of Bald Mountain theMcArthur fault fonns smaller. fresherappearing scarps In younger rocks(Photo 2). 11le ages of the basalt flowsnorth and south of the Fall River Valleyare not precisely known. so the bestevkience for recent movement on theMcArthur fault can be found in FallRiver Valley. A 'Nest-lacing scarp malluvium south of Big Lake is flanked bya large dosed depression Weakly de­veloped soil on the all\Mum suggeststhat the alluvium is of late PIe1S1oceneage. 11le scarp has a dtstincUy SleeperbNer 5eCtkln and a more gently s'op­ing upper section. suggeSIlng that atleast two earthquakes have displacedthe ground surface ~nce lhe alluviumwas deposlled

A parallel. mostly east-facing scarpcrosses the Fall River Valley about 2miles eaSl of the previously describedfault. This fault has formed a verysharp scarp. locally owr 6 feel high. inalluvium that has loIeTY \W.ak soil deveI·opment and is probably of Holoceneage. This sharp scarp. a closed de~es'

sian. and tonal lineaments in plowedfields indicate Holocene offset alongthis fault.

Maytl9ld Faull

A nonnal fault along the trend of theMcArthur fault to the north offsets theGiant Crater lava flow mapped byChampion and Donnelly-Nolan (unpub­lished) (FIgure 2). This fault is infor­mally called the Mayfield fault. The de.­termination of whether this fault is ac­tive is quite simJM. The Giant Craterflow has been dated by carbon-14analysis (I4e) 10 be about 10.600 yearso«i (Oonnelty.No1an and others. 1989).Because the Holocene Epoch is definedto be the last 11,000 years. this flow isa Holocene unit. and the faults that off­set it must have done so in Holocenelime. At Mayfiekllce Cave (Figure 2) itis possible to compare the 5-15 foothigh. relatively Hnear fault scarp withsmaller. more weathered lava subsi­dence scarps that surround two closeddepressions in the basalt flow. The dif­ferences suggest that fault offset hasoccurred since the lava cooled.

Scarps in the Giant Crater flow arereported to be up to 30 feet (10 m)high (Photo 3) (Dzurisin and others. inpress). Cakulation of a slip rate is pos.Sible for the Mayfield fault because arock unit of knO\Vll age is displaced bya kr\oo.Im amount. Here a to.OOO year­old unit is offset about 30 feet (10 me­ters). yielding a slip rate of about 1mm/yr. the same result as the HatCreek fault Although these sltp rateeslimates are rough approximations.they do show thai these tIoVO faults areabout equally active. Presumably.earthquakes are equally likely on lhesetwo faults.

PI!tVltle Fault

The Pittville rauh trends sorl1C\IIhatmore nortIl.....-e5terly than the Hal Creekfault or McArthur fault and bounds the

CAUFORNlA GEOlOGY MARCH 1991

east side of the Fall River Valley (Figure2). Tertiary basalt is faulted againstPleistocene basalt and lacustrine depos­its (Gay and Aune. 1958). This faultextends about 30 miles to the south­east. partly controlling the course of thePit River. Peterson and Martin (l980)mapped the north end of the PittvilJefault where it offsets the volcanic centernorth of Big lake.

fault zone (Figure 2) but did not mapthem in detail. The scarps are mostly"eroded and devoid of any more recentappearing scarps, like those along theHat Creek East fault or McArthur fault"«NCC. 1987). The exception to this isa sharp. east-facing scarp in early Pleis­tocene basalt which follows RockyLedge about 2 miles east of Burney andis up to about 200 feet high. Recencyof movement along this fault is indi-

DISCUSSION

The area of northern California be­tween lassen Peak and Medicine lakevolcano is cut by a series of active nor­mal faults. These faults form high,steep scarps called "rims~ where theyoffset Pliocene to early Pleistocene vol­canic rocks. The largest of these, theHat Creek Rim. is over 25 miles longand 1.600 feet high.

Despite theprominence ofthe fault scarps. itis difficult to de­termine if thefaults are still ac­tive. The vol­canic bedrock ofthe area is veryresistant to ero­sion and would beexpected to standas sleep escarp­ments for tens ofthousands ofyears. The deter­mination ofwhether a fault inthis area is activehas been basedon the latestPleistocene orHolocene depositsthat are locally cutby faults and onthe minor geo­morphic features

along the faults that are relatively short­lived and would be buried or obscuredby erosion in a few thousand years.

The simplest way to show that afault is active (has moved in Holocenetime) is to find a geological unit that isclearly of Holocene age and is clearlyoffset by the fault. This unequivocalevidence for active faulting is not com­mon but does exist along the Mayfieldfault. The Mayfield fault clearly offsetsthe Giant Crater lava flow along aIDmile-long segment of the fault. TheGiant Crater flow is 10.600 years old(Donnelly- Nolan and others. 1989). Iterupted at the beginning of Holocenetime. All of the fault offset thereforeoccurred in Holocene time.

........-.~ ... ... ".. --

To the north. a sharp west-facingscarp continues on approximately thesame trend. This scarp is marked byclosed depressions at its base. one ofwhich has been artificially enlarged foruse as a pond at a lumber mill. Thisscarp is the 50 foot high. vertical. blackcliff visible east of State Highway 89about 2 miles south of McArthur­Burney Falls State Park.

cated by closed depressions at the baseof the scarp and scarplets. troughs, andbenches in talus. In the field. closeddepressions were obselVed along theside-hill troughs in talus. The exposedsurfaces of boulders along these troughsranged from very fresh to significantlyweathered, suggesting that the talus hasbeen ~slirred" by faulting in Holocenelime.

Photo 3. Scarp of the Mayfield fault about 1 mile south of the Maylield Ice Cave.Man in center of view, about 314 of the way up the scarp. provides scale. Photo byJ. Donnelly-Nolan.

wec (1987) examined numerousQuaternary faults west of the Hat Creek

Faults West of theHat Creek Fault Zone

Several unnamed faults west of theHat Creek fault zone offset Tertiarythrough early Pleistocene volcanicrocks. South of the Pit River. east- andwest-dipping normal faults are distrib­uted over a broad area east of Burney.These faults tend to be relatively short(generally 2 to 5 miles long) and broadlyCUIVed. MacDonald (1964). Gay andAune (1958). and Lydon and others(1960) mapped these faults as offsettingMiocene. Pliocene. and Plio-Pleistocenevolcanic bedrock.

Recent move-ment is indicatednorth of Fall RiverValley where thePiltville fault formsa scarp in latePleistocene basalt.At one locality. a 4to 10 foot scarp inbasalt has openfissures up to 7feet deep on itsupthrown side.Alluvium on theupthrown side ofthe fault has eitherbeen offset fromits equivalent onthe downthrownside or has beenponded by tiltingof the upthrownblock. This allu­vium is probablyof Holocene agebecause it hasweak soil develop-ment. and suggests that fault movementhas occurred in Holocene time.

56 CALIFORNIA GEOLOGY MARCH 1991

[n most cases the age of the offsetunits is not precisely known but can beinferred from the geologie history of thearea or weathering and development ofsoil on the surface. On the Hat Creekfault. Muffler and others (1989) identi­fied outwash Irom Tioga age glaciersthat is offset by the fault. Because theTioga glaciers receded 12.000 to15.000 years ago. this is not a Holo­cene unit it is a very late Pleistoceneunit. however. and most of the displace­ment can be reasonably assumed tohave occurred in Holocene time.

The southern end of the McArthurfault was shown to be active by a some­what less direct method. The fault hasformed a scarp in alluvium mapped asQuaternary by MacDonald (1964). Be·cause this alluvium is only a few milesdownstream from the end moraines ofTioga age glaCiers (Kane. 1975) it isassumed that the alluvium is outwashfrom the Tioga age glaciers or younger(VJilIs. 1990). The displacement of lat­est Pleistocene (Tioga) outwash oc­curred in latest Pleistocene or Holocenetime. so the fault is probably active.

In the Fall River Valley there are nowell-dated lava flows or glacial deposits.but it is still possible to arrive at roughestimates of the ages of alluvial units bythe amount of soil development. Asedimentary deposit exposed at the sur­lace will accumulate organic malter andclay. gradually building up soil horizons.Measurement of the thickness of thesoil horizons and degree of soil develop­ment enable a comparison with otherareas where the ages of soils areknown. The strength of soil develop­ment in Fall River Valley suggests thatthese soils have fonned relatively re­cently. perhaps in the last 10.000 to20.000 years (latest Pleistocene toHolocene time), Therefore. much ofthe offset of the surface of the valleyprobably occurred in Holocene time.

When there appears to be no latestPleistocene or Holocene unit that is cutby the fault. it may be possible to deter­mine whether a fault is active by thedistinctive landfonns along the fault. [nareas of alluvium or relatively soft bed­rock. distinctive landform features areoften the primary means of evaluating

active faulling: a sharp, steep scarpformed recently: more eroded scarpsare older. [n the resistant volcanic bed­rock of northeastern California. verticalscarps may have formed many thou­sands of years ago. Here. smaller scalefeatures. such as fissures near the topsof scarps or linear troughs in the talusat the base provide some clues to therecency of movement.

Along the Rocky Ledge fault. east ofBurney. a trough in the talus probablymarks the location of the faull. Be­cause this trough occurs below thesteepest part of the scarp. one wouldexpect it to be filled relatively rapidly bytalus from above. Also along this fault.the boulders in the talus are in a varietyof positions. with different bouldersshowing fresh and variously weatheredsurfaces facing up. Such evidence sug­gests that the talus has been disturbedrelatively recently. perhaps by faulting.

Fissures along faults and near thecrests of scarps are also thought to berelativel~ short-lived features. The fis­sures along parts of the Hat Creek andPittville faults have near vertical or over­hanging sides. Those along the HatCreek fault can be shown to haveformed in Holocene time because thefault offsets Tioga outwash. It is pos­sible to assume then that similar fis­sures. such as the smaller. but sharpfissures along the Pittville fault are ofsimilar age.

SEISMICITY

Small earthquake epicenters are scat­tered over a broad area surrounding theHat Creek and McArthur faults. Thesmall number of recorded epicenters isdue in part to a low level of seismicityin the area at present and in part to alack of instrumentation. The Universityof California Berkeley Catalog (Bolt andMiller. 1971) shows a north-northwesttrending alignment of five M~4 eventsrecorded between 1940 and 1972.These epicenters roughly paralleL andlie west of the Hat Creek Rim. consis­tent with a west-dipping nonnal fault.These events are poorly located. how­ever. and cannot be definitely related toany surface faults.

CONCLUSIONS

A zone of active normal faults ex­tends over 60 miles north from nearLassen Peak to the south flank of Medi­cine Lake volcano. The major strandsof this fault zone. the Hat Creek.McArthur. Pittville. and Mayfield faultsare each 15 to 35 miles long. All haveformed west-facing scarps in Quater­nary volcanic rocks and alluvium. Sev­eral other shorter faults west of the HatCreek fault are also active. The mostprominent of these has formed an east­facing scarp along Rocky Ledge.

These faults can be shown to be ac·tive because they displace late Pleisto­cene and Holocene deposits and be­cause they have fanned distinctive land­forms along their scarps. Slip rates canbe calculated for two of these faultswhere geologic units of known age areoffset by a known amount. Slip ratesfor both the Hat Creek fault and May­field fault are about 1 mm/yr. The lackof major historic seismicity in this areasuggests that the intelVal between earth­Quakes is relatively long.

ACKNOWLEDGMENTS

Many thanks are extended to GlennBorchardt and Bill Bryant. of the Divi­sion of Mines and Geology. who as­sisted me with the investigation that thisarticle is based on. The article has beenimproved by helpful reviews by M. Man­son and K. Blean of the Division 01Mines and Geology and J. Donnelly­Nolan of the USGS.

REFERENCES

Anderson. CA. 1940, Hat Creek LavaFlow: American Journal of SCience.v. 238, no, 7. p.477-492.

Bolt, B,A. and Miller, R.D.• 1975 Catalogueof earthquakes in northern Californiaand adjoining areas. 1 January 1919-31.December 1972: Seismographic Sta­lions, University of Calilornia. Berkeley.

Bonilla, M.G.. Mark. AK and Lienkaemper.J.J., 1984, Statistical relations amongearthquake magnitude, surface rupturelength. and surface fault displacement:Bulletin ot the Seismological Society ofAmerica. v. 74. p. 2379-2411.

Champion. D.E.. and Donnelly-Nolan. J.M.,(unpublished). map of the Giant Crater1I0w. scale 1:48,000.

more.

CALIFORNIA GEOLOGY MARCH 1991 57

Clynne. M.A.• and Mul1ler. LJ.P., 1989,lassen NatIOnal Pari!. and VIClnlly, inMul1lef, L.J.P. editor, South Cascadesarc volcanism. CaUlomla and southemOregon: 28th IntematlOnal GeologICalCongress field tnp guidebook T312,American GeophYSICal UnIOn. p, 3-14

Diller. J.S.. 1908. Geology 01 the Tay­lorsvIlle reglon. CabfOfl1la' U.S Geologl'cal Survey BuJleon 353. 128 p.

Donnelly-Nolan. J.M.. ChamptOO D.E"Miller. C.P.• and Tnmble. O.A., 1989,Implica!looS of post 11.000 year volcan­ism at MediCIne lake volcano. northernCaIilOfnla. Cascade Range U.S Geo·logICal Survey Open-File Repon 89-178.p. S56-S80

Ozunsm. O. OonneIIy·Nolan. J M" Evans.JR. and Walter. SR. In press, Crustalsubsidence. setSff\ICfty. and structurenear Mediclne lake volcano, Cab'(lfl"lla:manuscnpt submtned to Journal of Ge0­physical ResearCh,

Fnch. RH .• 1933. Slump scarps Journal ofGeo6ooY. v 41. P 647·649

Gay. TE, Jr.• and Aune. a...... 1958. Ahu­ras Sheet Calitomla 0MsI0n of MInesgeologIC map at Call1orrua, scale1:250.000.

Gul1anlJ, M. C1ynne. MA. Mul1ler. L.J.P..and SmIth. J,G" 1989. Spatial, temporatand composlllOnaltrends 01 volcanISm inthe Lassen r&g1Of'l 01 northeastern Ca~­

fomIa. If! Muffler. UP.• Weaver. CS..and Blackwell. 00 editors, GeoIogtcaI.geophySICal and tectOOlC sellJng 01 theCascade Range; U,S. GeologIcal SurveyOpen File Report 89-178, p.581-603

Hart. E W,. 1990. Fauh rupture hazardzones In CaIiiOfl'lla. DrvlSIon 01 Mmesand Geology SpecIal PubllcatlOl'l 42,24 p.

JenkJns, O.P., 1938. Geornorptic map ofCaUlorf'lla Calliorflla [)MslOfl of Mmesand Geology, scale approxImately1:2.000.000

Kane. P. 1975. The glaoal geomorphologyof the lassen VolcanIC NallOflal Pari!.area: Ph.D. dissenalJon (Geography).UnivefSlty of California Berl!.eley (Url>published).

Lydon. PA. Gay. T.E. Jr .• and Jenf'llngs.C.W.• 1960. Westwood sheet CalilornaDrvlSIon of MlOes geologIC map 01 Call·10rTIIa. scaJe 1:250.000

MacDonald. G...... 1964. Geology of theProspect Peak quadrangle U S Gao-

Glossary

logICal SUrvey geologIC quadrangle mapGQ.345. scale 1:62.500.

Mullier. L.J.P.. Clynne. M.A.• and HolCOmb.R.T.• 1989. Late Quaternary fauhlng 01the Hat Creek basalt (abstract): EOS(lransactJOnS of the Amencan Geophyst­cal UI'lIOfI). v 70. no 43. p. 1310.

Muffler. LJ.P. and Campbel. H.W. 1984.Losl Creek roadess area. Calilorflla. If!

Marsh.S.P.• Kropschol. S.J. and Qduo.son. R.G editors. Wilderness tT1lf'lEIralpoteolJal' U.S GeoIoglcal Survey Pro­les5lOf'lai Paper 1300. p. 283·285

Sharpe. CFS.• 1938. Landslides and re­fated phenomena: Columba UrwefSJlyPress. 137 p.

Wills. C.J.• 1990. Hat Creek. McArthur andrelated faults. Shasta. Lassen. Modocand Slsklyou counlles. CaJiforflla OM­SIOn 01 MlneS and Geology fauh evalu­atIOn report (FER) 209. 14 p. (unpub­lished).

Woodward-Clyde Consultants, 1987. Plt1Forebay dam (97-110). EvaluallOn ofS&lsmlC geology. 5elsmlClty and earth­quake ground motIOns. unpublishedconsuhants' repon. 48 p.. appendiCeS.

en echelon faults: Faults that occur as overlapping or in staggered arrange­ment. Each fault in this pattern is relatively short but collectively they fonn alinear zone.

Holocene: 11.000 years ago until the present

normal fault: A fault in which the overlying side Changing wain appearsto have moved downward relative to the underlying side ['footwall'l

Pleistocene: 1.8 million to 11.000 years before the present.

Quaternary: 1.8 miJUon years ago until the present.

shield volcano: A shield volcano is a broad. low dome buill by lava or ashf\oo.l.rs. This type of volcanic edifice was so named because in profile it re­sembles a Roman sokIier's shield.

Tertiary: 65 miIbon 10 1.8 million years before the present.

tonal Iineame.nt: Usually a sbght color contrast on the ground surfacecaused by <;Ojj and/or wgetalKln

58 CAUFORNIA GEOlOGY IoIAACH '"1

Products of the Alquist-PrioloFault Evaluation and Zoning Project

Compiled By

C.J. WILLS, GeologistDivision of Mines and Geology

Geologists of the Division 01 Mines and Geology's Faull Evaluation and Zoning Project investigating an exposure of the Honey Lakefault in wave-cut bluffs at Honey Lake, Lassen County. The main strand of the fault ties a few feet 10 the right of the kneeling geologist,a thin vertical dark stripe across the lighter-colored lakebeds. This fault exposure is at the end of a nOl1heasHacing scarp in laleslPleistocene to Holocene sediments. Photo by E. W. Hart.

INTRODUCTION

The Alquist-Priolo Special Studies Zones (APSSlj Act wasenacted in 1972 "\0 assist cities. counties. and state

agendes in the exercise of their responsibility 10 prohibit thelocation of developments and structures for human occu­pancy across the traces of active faults" (Hart. 1990). TheAlquist-Priolo fault evaluation and zoning project (A-P project)is responsible for determining which faults are Msufficiently ac­tive and well-defined" for zoning and issuing Official SpecialStudies Zones Maps.

The following list of products of the A-P project is intendedto make information about the project more readily availableto the public. A recent evaluation of the A-P protect byRoben Reitherman and David Leeds. under contract to theDivision of Mines and Geology (DMG). found that. althoughthe project was generally effective in helping to mitigate thehazard of surface fault rupture, many people were unaware of

CALIFORNIA GEOLOGY

the information about faults that is contained in DMG publi­cations and files. Reitherman and Leeds recommended thatthe staff of the A-P project do more to publicize their publi­cations and other products of the protect. Reitherman andLeeds' report has recently been released as Open Rle Report90-18.

Since the passage of the APSSZ Act. staff of the FaultEvaluation and Zoning Project published numerous reportson the Act and the surface fault rupture hazard. These. aswell as unpublished files of geologic information. are listedbelow. Notations next to each entry are the publicationnumber and price of DMG publications: CG _ CAUFORNIAGEOLOGY. N - DMG Note. SP ". Special Publication, SR ­Special Report, * indicates an outside publication not avail­able from DMG. o.p. indicates t;lat the publication is out ofprint and no longer available. Numbers alone (for example

MARCH 1991 59

89-16) are Open File Report numbers. Prices for DMG publi­cations are given below the publiciJlion numbers. Many backissues of CALIFORNIA GEOLOGY magazine are also avail­able for $1.25 each,

The publications listed below have been arranged into livegeneral categories: Implementation of the Alquist-Priolo Act.Post-Earthquake Investigations. Studies of Individual Faults,Summary Reports, and Consultants' Reports.

AVAILABILITY

Reports listed here are available for reference at offices ofthe Division of Mines and Geology in Sacramento, PleasantHill. and Los Angeles. Some reports are also available forreference at county and university libraries. Copies of OpenFile Reports and back issues of CALIFORNIA GEOLOGY maybe purchased by prepaid mail order or over-the-counter fromthe Geologic Infonnation and Publications Office in Sacra­mento. Special Publications and Special Reports can be pur­chased using the order lorm in this or any issue of CALIFOR­NIA GEOLOGY. Official Alquist-Priolo Special Studies Zonesmaps are available for reference and, in some cases. can bepurchased at the offices of the city or county affected by theSpecial Studies Zone (usually at the planning department).

CG

N.49Free

SP 47o.p.

CG

CG

•

CG

Zoning for surface fault hazards in California ­The new Special Studies Zones maps,by E.W. Hart. 1974: v. 27. n. 10. p. 227-230.

Geol09ic guidelines for evaluating the hazard ofsurface fault rupture, by E.W. Hart. 1975.

Active 1ault mapping and evaluation program­10-year program 10 Implement Alquist-Priolo SpecialStudies Zones Act. 1976.

The review process and the adequacy of geol091creports, by A.M. Stewart, E.W. Hart. and P.Y. Amimolo.1976: Bulletin 01 the International Associalion of Engi·neering Geology, no. 14. p. 83-88. (Reprinted in CALI­FORNIA GEOLOGY, v. 30 n. 10, p. 224-229).

Geologic review process, by E.W. Hart. and J.W.Williams. 1978: v. 31. n. 10, p. 235-236.

Zoning for Ihe hazard ot surface fault rupture in Cati­fornia, by E.W. Hart, 1978, in Proceedings of the Sec­ond International Conference on Microzonation, SanFrancisco, Nov. 26 - Dec. 1. 1978: NSF Special Publica­tion. p. 635·645.

Fault Evaluation and Zoning Program, by E.W. Hart,1980: v. 33, n. 7, p. 147-152.

OFFICES OF THEDIVISION OF MINES AND GEOLOGY

GEOLOGIC INFORMATION AND PUBLICATIONS660 Bercut DriveSacramento. CA 95814-0131(9161445-5716

BAY AREA REGIONAL OFFICE380 Civic Drive. Suite 100Pleasant Hill, CA 94523-1997(4151 646-5920

SOUTHERN CALIFORNIA REGIONAL OFFICE107 South Broadway. Room 1065Los Angeles, CA 90012-440212131 620-3560

* Zoning for surface-faulting in southern Ca1lfornia. byE.W. Hart. 1986, in Proceedings of ConferenceXXXII-Workshop on future directions in evaluatingearthquake hazards in southern California, Nov. 12­13. 1985: U.S. Geological Survey Open File Report 86·401. p. 74-83.

90-18 A study of the effectiveness of the Alquist-Priolo$14.00 Program, by A. Reitherman and D.J. Leeds. 1990.

POST-EARTHQUAKE INVESTIGATIONS

The primary means of testing the effectiveness of theAlquist-Priolo Act is by mapping surface fault-rupture follow­ing significant earthquakes to determine the magnitude offaulting and to see if the rupture occurred within the SpecialStudies Zones. The mapping of fault rupture also enablesthe geologists on the A-P project to obselVe fault-producedlandfonns before they are modified by erosion.

CG Ground rupture associated with faulting - Orovilleearthquake, August 1975, by E.W. Hart 1975: v.28,p. 274-276.

SR 124 Ground rupture along the Cleveland Hill fault,$6.00 by EW. Hart and J.S. Rapp. 1975. in R.W. Sherburne.

and C.J. Hauge. editors. Oroville. CalUornia, Earthquake1 August 1975, p. 61-72.

* Geologic setting, historical seismicity and surfaceeffects of the Imperial Valley earthquake, October 15,1979, Imperial County California, by E. Leivas. E.W.Hart. R.D. Mcjunkin. and C.R. Real. 1980. in ImperialCounty, California, Earthquake, October 15, 1979:EERI Reconnaissance Report. February 1980, p. 5-19.

IMPLEMENTATION OF THE ALQUIST-PRIOLO ACT

The A-P project is designed to identify active faults thatmay be hazardous to structures Irom surface fault-rupture.Publications that describe the objectives and recommendationsof the Act. as well as the progress of zoning, have been pub­lished periodically,

Official Maps of Special Studies Zones. by the DiVision01 Mines and Geology. 1974-1989. As of January t,1991,488 new and revised Official APSSZ maps havebeen issued. Special Publication 42 (below) providesan index to these maps and describes how they can bepurchased.

SP 42 Fault-rupture hazard zones in California, by E.L. Hart.$2.00 1990. Includes an index map which identifies aJi 7.5

minute topographic maps in which AP Special StudiesZones are located.

CALIFORNIA GEOLOGY

81-5$5,00

Preliminary map of October 1979 fault rupture,Imperial and Brawley faults, Imperial County,California, by E.W. Han, 1981.

MARCH 1991

8().12Op.

SA 150$700

SA 150$HIO

Preliminary map of surface rupture ..sociatedwith the Mammoth uke. earthquake•• May 25 and 27,1980, by W.A. Bryant, GC. Tay\of, E.W. Hart, and J.EKahle, 1980,

Surface rupture a.socialed wllh the Mammolhuke. earthquakes of 25 .nd 27 May, 1980. by G C.Taylor, and W.A Bryant, 1980. m R,W. Sherburne. editor,Mammoth LIkes, Camornia earthquakes of M.y 1980,p.49-67.

Aocld.lI. gener.tecl by the Mammoth LIkesearthquake. of May 25 and 27, 1980, by W.A. Bryanl,1980. In R W Sherburne, edilor, Mammoth Lakes, Cali­fornia earthqu.lkes 01 May 1980, p 69-73.

STUDIES OF INDIVIDUAL FAULTS

Beginnlf'lg In 1976. a Fault Evaluation Report (FER) wasprepared for each examined fault The FER summarizes dataon the location. recency of oclivlty. and sense and magnitudeof displacement A total of 225 FERs were prepared onfaults throughout California FERs are nol published EachFER includes a summary of pertinent lNOJ'k by other ge0lo­gists (published and unpublished). as \Nell as interpretations ofgeomorphic evidence observed on aerial photographs andlimited field in....esUgation. Many FERs contain detailed. anno­lated maps sunmarizing geomorphic and other evidence forfault recency and locaHon. The FERs are the primary reportsjustifying Ihe decIsion to zone or not zone a fault under theAlquist-Pnok> Act. although some of this information is pub­lished as open-file and other reports.

SR150 Planned zoning of Ktiw laulls associated with the$7.00 Mammoth Lakes earthqu.kes of Way 1980, by E.W FERs Fault E....lu.tlon Reports. by Fault Evaluaoon and Zon-

Hart. 1980, III R W Sherburne, editor. Mammoth Lakes, lflg PrOf8Cl stat! 1976-1991. Copes of the unpubltsnedC.lifornla e.rthquakes of M.y 1980, P 137-141 FERs are av3llable lor relerence '" the san Frarosco

Ground rupture, Coalinga earthquake of 10, JuneBay and los Angeles reglOrl81 offICeS of DMG An Inde.

CG to FERs and copes 01 FERs on rr'IICfofiche are now avaIl-1983, by A.D. McJunlon. and E.W Han. 1983 v 36. n. 8. able as Open File Reports 90-9 10 90-14 (see belOw).P t82-184

,1-6 Evidence of Holocene movement of the SanSP 66 Suriace faulting northwest of Coalinga. Calitornla, $500 Andreas 'ault zone, northern San Mateo County. Call·$12,00 June and July 1983, by E W Hart. and A.D. McJunlon. lornia, by T C, Smith, 198t

1983, in J,H Bennen and R W Sherburne. editors. The1983 Coalinga, California earthquakes, p 201-219 81-7 Sargent, San Andreas and Calaveras lault zones:

$5.00 evidence lor recency in the Wa,",nville east, Chltten·SP66 Evidence tor suriace faulting associated with the elen and San Felipe quadrangles. California. by W.A.$1400 Morgan Hill earthquake 01 April 24, 1984, by EW Hart, Bryant, DP Smitn, and E.W Hart. 1981

1984. m JH Bennett and R.W. Sherburne. edilors, 1984,The 1984 Morgan Hili, Calilornia earthquake, 161·173. 81·8 Recently active strands 01 the Greenville fault,

$5.00 Alameda, Contra Costa and Santa Clara counties.CG Fault rupture associated wilh the July 21, 1986 Chal· California, by E.W Hart.I98\.

lant Valley Earthquake, Mono and Inyo counties, Cali-fornia, by J.E, Kahle. w.A. Bryant. and E.W. Hart, 1986: 81·9 Evidence for recent lauillng, Calaveras andv. 39. n. 11, p 243-245. 55.00 Pleasanton faults. Diablo and Dublin quadrangles.

Magnitude 5.9 North Palm Springs earthquake, July 8.Calilornla, by E.W. Han. 1981.

CG1986. Riverside County, California: lifeline damage, SP 62 Southern Hayward laull zone, Alameda lind Santaby Glenn Borchardt, and MW. Manson. 1986: v. 39. n, $1800 Clara counties, Canlornla. by W.A. Bryant. 1982, in11, p. 248-252. Proceedlngs-Conference on earthquake hazards of

the eastern San Francisco Bay area, p. 35·44.CG Preliminary report: Surface rupture, Superstition Hills

earthquakes of November 23 and 24, 1987, by JE. 84-54 Evidence 01 recent faulting along the Owens Valley,Kahle, C.J. WillS. EW. Hart, J.A. Treiman. A.B. Green- $5.00 Aound Valley, and White Mountains lault zones, lnyowood, and R.S.Kaumeyer, 1988 v. 41. no 4. p. 75-84 and Mono counties. Call1ornia, by W.A. Bryant. 1984

CG liquefactIon at Soda Lake: Effects 01 the Chittenden 84·55 Evidence 01 recent laulting along the Mono lakeearthquake swarm of April 18, 1990, Santa Cruz 5500 faull zone, Mono County, California, by W.A. Bryant,County, California. by C.J Wills. and MW Manson. 198'1990: v. 43, n. 10. p 225-232

84·56 Evidence 01 recent faultIng along the Antelope

• SurfKe fissure. and the mapping of DNG Special $5.00 Valley faulf zone, Mono County, California. by W.A.Studies Zones, by EW. Hart, 1990. In George Retd. Bryant. 1984.edilor. What we have learned from the October 17,1989 7.1M lama Prieta earthquake: 16th Annual Saber 88·14 Recently actIve trKes 01 the Newport·lnglewoodSooety SympoSium Proceedings Volume, p 87·99 $6.00 laull zone. los Angeles and Orange counties, Calltor-

The search for fault rupture and the signiftcance 01nla, by W.A. Bryant. t988.

SP 104$t2.00 ridge-lop fissures. Santa Cruz Mountains, California. CG A neotectonic tour of the Death Valley fault zone, by

by E.W. Hart, W.A. Bryant. C.J. Wills. and J.A. Tr81man. C.J WIlls. 1989 v 42. no. 9. p. t95-2OO.1990, III S,R McNutt, and R.H. Sydnor. editors, TheLoma Prlela Earthqu.lke of OCtober 17, 1989, P 83-94 CG Deep Springs laull, Inyo County. CalifornIa. An e.-

The Mono Lake earthquake 01 OCtober 23, 1990, byample of the UN: of relatlve-dating techniques. by

CG W.A. Bryant. 1989: v 42. no. 11 p.243-255.SA McNutt, W.A Bryant. and R. Wilson, (in press).

CAUFORNIA -GEOt.OGY UARCH 1991 ..

*

90·'$5.00

90-10$10.00

90·11$10.00

The Rose Canyon faull zone; a historical review, byJ.A. Treiman, 1990 (in press): in Seismic risk in the SanDiego region, a workshop on the Rose Canyon faultsystem: Proceedings volume of a workshop sponsoredby the Southern California Earthquake PreparednessProject. June 29-30. 1989,

Index 10 lault evaluation reports prepared 1976­1989 under the Alquist-Priolo Special Studies ZonesAct, by C.J. Wills, P. Wong, and ew. Hart 1990.

Microfiche copies 01 Fault Evaluation Reports lornorthern California, by Division of Mines and Geologystafl.

Mlcrollche copies of Faull Evaluation Reports lorthe southern Coast Ranges, by Division of Mines andGeology staff.

84-52$5.00

86-3$5.00

88-1$5.00

89-16$5.00

Summary report: Faull Evaluation Program,1983 area (Sierra Nevada region), by E.W. Hart, W.A.Bryan!, and T.C. Smith, 1984.

Summary report: Fault evaluation program,1984-1985, southern Coast Ranges region and otherareas, by E.W. Hart, WA Bryant, M.W. Manson, andJ.e. Kahle. 1986.

Summary report: Fault evaluation program,1986-1987, Mojave Desert region and other areas, byE.W. Hart. WA Bryan!, J,E. Kahle. M.W. Manson, andE.J. Bortugno. 1987.

Summary report: Faults evaluated 1988-1989 Inthe southwestern Basin and Range and augmen­tation areas, by ew. Hart. W.A. Bryant. C.J. Wilts,J.A. Treiman. and J.E. Kahle, \989.

90-12 Microfiche copies of Fault Evaluation Reports for$10.00 the Transverse Ranges, by Division at Mines and Geol­

ogy stall.

90-13 Microfiche copies of Fault Evaluation Reports for$10.00 the Peninsular Ranges, by Division of Mines and Geol­

ogy staff.

90-14 Microfiche copies of Fault Evaluation Reports for$10.00 eastern California, by Division of Mines and Geology

stafl.

SUMMARY REPORTS OF AP REGIONS

The work plan of the A-P project from 1976 to 1991 hasbeen to evaluate faults in ten separate regions of the state ona priority basis. One to two years was allotted 10 sludy eachregion. Faults lying outside a given work area were alsoevaluated when the need arose. For each fault. a FaultEvaluation Report is prepared. Following the evaluation ofeach region. a report briefly summarizing the data containedin the FERs is released as an open-file report.

77-8 Summary report: Fault Evaluation Program,$5.00 1976 area (western Transverse Ranges), by E.W. Hart.

E.J. Bortugno. and T.C. Smith, 1977.

CONSULTANTS' REPORTS

GeologiC consultants' reports assessing the hazard of faultrupture on specific sites are submitted by cities and countiesto the Division of Mines and Geology. These are kept onpublic file in the Bay Area Regional Office of the Division ofMines and Geology. Reports are available for reference butcannot be removed from the office. Copies of these reportscan be obtained by special arrangement. Index maps of theconsultants' reports were issued periodically. and a completedirectory of the reports, received in compliance with theAPSSZ Act through December 31,1989. was issued in1990.

A-P File, reports by consutling geologists, 1974-1991:reporls for sites within Special Studies Zones officiallysubmitted to the Division of Mines and Geology in compli­ance with the APSSZ Act. Over 2,500 reports are on tileas of 4/1/91.

C File, reports by consulting geologists, 1974·1991:reports that either predate the Special Studies Zones,are outside the Zones, or are for developments that areexempt under the APSSZ Act. Over 760 reports are onlile as of 4/1/91.

78-10$5.00

79-10$5.00

81-3$5.00

SP 62$18.00

Summary report: Fault Evaluation Program,1977 area (Los Angeles Basin region), by E.W. Hart.D.P. Smith. and T.C. Smith, 1978.

Summary report: Fault Evaluallon Program,1978 area (Peninsular Ranges-Salton Trough region),by EW. Hart. D.P. Smith, and R.B. Saul, 1979.

Summary report: Fault Evaluation Program,1979-1980 area (southern San Francisco Bay region),by E.W. Hart, W.A. Bryant, and T.C. Smith. 1981.

California's Fault Evaluallon Program-southernSan Francisco Bay region, by E.W. Hart, T.C. Smith,and W.A. Bryant. 1982, in Proceedlngs---Conference onearthquake hazards of the eastern San Francisco Bayarea, p. 395-404.

77-6o.p.

84·31$5.00

89-5$5.00

90-15$15.00

Index to geologic reports for sites within SpecialStudies Zones, by W.Y.C. La. and J.G. Moreno. 1977(superseded by OFR 84-31).

Index to geologic reports for sites within SpecialStudies Zones, by P. Wong, 1984. (Index map to the APFile reports).

Index to geologic reports for development siteswithin Special Studies Zones in California, July 1,1984 to December 31, 1988, by P. Wong. 1989. (Updateof index map to the AP File reports).

Directory of fault investigation reports lordevelopment sites within Special Studies Zones inCalifornia, 1974-1988, by P. Wong. E.W. Hart. and C.J.Wills, 1990. (Listing of all AP File reporlS through Decem·ber 1988).-"'::

83-10 Summary report: Fault Evaluation Program,$5.00 1981-1982 area (northern Coast Ranges region), by

EW. Hart, W.A. Bryant, and T.C. Smith, 1983.

62 CALIFORNIA GEOLOGY "'ARCH 1991

Preliminary Review Maps of ProposedALQUIST-PRIOLO SPECIAL STUDIES ZONES

Preliminary Review Maps Issued May 1, 1991(Map numbers keyed to index map)(~[ "', ~i: ; .....~:,i

,J _. ill 1. Fields Landing\ /( I 2. FortunaJ. ........ , C ,1 - - ~ - - 3.. Hydesville

'J - '" 4. Sams Neck! 5. Dorris

111·····\ j 6. MacdoelI /) ~ _~ __ ~_ ... l t 7. Sheep MountainI • ~-... '] J~' t 8. Red Rock Lake: \' .,'; .. 9. Bray"'---l.__ \ ' '..... 10. Sharp MIn., ~ I

~- "- 11. TennantJ..- 1' , , •• ..,. ~-> ;.';.:. -: 12. Garner MIn.(' ,J I _ ,~__ 13. Rainbow MIn.

......... 1',~ - "J--.c::~ " .,.... 14. Fort Bidwell•..• : ...... 1... ~;. 15. Lake City

t- ."'-..... . _. V F 16. Cedarville

'\

' ""-,\ I~, I., I ,f >" 17. Warren Peak, ".I ",,,.,, ..

\

\ ... ,~- - ..'\ .,,' ~" 18. Eagle Peak.. ... l ./ ...",''''

•••• , --, (''' M _" ,. _ )',

-~ : j ..'?"~.:). '-' ,,' "~~'''_._ )J' .'J,r--'~- " .. , ) ,~IA.'. :.~ i ' , ••-" '"'__ "

19. Eagleville20. Snake Lake21. Porcupine Bulle22. Indian Spring Mtn23. East of Pondosa24. Timbered Craler25. Day26. Burney Falls27. Dana28. Fall River Mills29. Piltville30. Burney31. Cassel32. Hogback Ridge33. Coble Mountain34. Murken Bench35. Jellico36. Old Station

• Revised zone map

37. Swains Hole38. Standish39. Stony Ridge -'40. Milford41. Herlong42. Calneva Lake43. McKeslck Peak44.• Doyle45. Constantia46.• Los Galos47.• Laurel48.• Pitas Poinl49.· Fillmore50. Moorpark51. • EI Monte52.• La Habra53. La Jolla54. Point Loma

" ..

;-,\,..,

.. 1

"

-

----'l'I------f------jf" ,------',

..

~~",,,.

\ "- ; - - - - -, ,,... .... ...... : . .. .,

- -,-- ,

'" ...... ....... -,

CountiesHumboldt Santa Claralassen Santa CruzLos Angeles ShastaModoc SiskiyouOrange VenturaSan Diego

SACRAMENTO AREA• Publications & Intormation

660 Bercut DriveSacramento. CA 95814(916) 445·5716

SAN FRANCISCO AREA380 Civic Drive. Suite 100Pleasant Hill, CA 94523-1997(415) 646·5920

LOS ANGELES AREA107 S. Broadway,Room 1065los Angeles. CA 90012(213) 620·3560

T he proposed new and revised Alquist Priolo Special Studies Zones Maps are available for n.wiew purposes. Following a review periodthat ends August I. 1991. they will be superseded by Ollicial Maps on November I. 1991. at which time the zoning l.>e<:omes effective_

Copies of the Preliminary Review Maps may be examined at the offices of affected cilies and counties. and at the district offices 01 theDivision 01 Mines and Geology. Copies may be purchased from Blue Print Service Company. 1147 Mission Street. San Francisco. CA94103. (415) 495-8700. ext. 550.

The 1990 edition of Special Publication 42 is also available for information on OlliciaJ Maps of Special Studies Zones previously issued,and for provisions of the Alquist-Priolo Special Studies Zones Act. This reference. titled -FauIt-nJpture Hazard Zones in California: is avail­able for $2.00 from the Division of Mines and Geology. PO. Box 2980. Sacramento. CA 95814. or from the offices listed above.X"

CALIFORNIA GEOLOOY MARCH 1991 63

Significance ofCalifornia's Mining Industry

By

DON DUPRAS, GeologistDivision of Mines and Geology

•:\ ~.\ 'i"'., .

'"•••

• .''. 1_ ..•

Baxter iron mine, located about 40 miles east of Barstow, San Bernardino County. Iron ore from this mineis used to manufacture pol1land cement. Mining operations are intermittent. Photo by John Rapp.

INTRODUCTION

M any Californians are unaware ofthe importance of mining in our

lives. Few of us are able to relate howmined products contribute to our every­day lives: fewer still can relate how min­ing benefits our economy. Althoughmany Californians view mining as a de­structive. exploitative business with adismal history. this industry has pro­foundly enriched our lives and will con­tinue to do so far inlo the future. With­out mining. there would be no high-riseoffice buildings. no factories. hospitals.airliners. cars. televisions. or windows:

our civilization could not exist withoutmining. Even the lood we eat and ournutritional health is directly tied to min~

ing (see inset box on page 68).

California has been a leading mineralproducing state for many years. Whythen are so few of us cognizant 01 itsimportance? The following list includesfour reasons why mining in California isnot generally recognized by the publicas significant. (1) The mining industry.including oil and gas. directly employsonly about 48.000 California workers

(about 0.12 percent of the population)(Fay and others. 1991). (2) Mining op­erations occupy very little space-tessthan 1 percent of the surlace area 01California (Fay and others. 1991). (3)Many mines are in remote areas andmining operations near urban areas arehidden from view by berms and vegeta­tion screens. (4) Because most mineralproducts undergo extensive processingto make finished goods, the publicrarely associates the commodities theybuy with mining operations (AmericanMining Congress. 1972).

CALIFORNIA GEOLOGY MARCH 1991

TABLE 1. NONFUEL MINERAL PRODUCTION IN CALIFORNIA' (U.S. Bureau of Mines statistics).

1988 1989 E1990

Mineral Quantity Value Ouantify Value Ouantity Value(thousands) (thousands) (thousands)

'Boron Minerals ... thousand metric tons "6 $429,667 562 $429,806 565 $404,476Cement:

Masonry ........ .... thousand short tons 6 730 W W W WPortland. --- ....... thousand short tons 10,423 601,152 10,911 642,020 10,500 619,500

Clays .. .......... -- ........ ...... ... metric tons 2.015,488 31.620 2,195,830 39,243 2.342.092 41.222Gemstones .. .............. ........................... NA 3.365 NA 2,982 NA 2,400'Gold .. ...... ............ ........ ..... kilograms 22,442 316.246 29.804 366,595 32.000 390.952Gypsum ................. thousand short tons 1,490 11,222 1.734 13,066 1,771 13,743Lime ...... ..... -- ....... thousand short Ions 458 20,242 395 24,503 366 22,703Peat ...... .... --- ..... . thousand short tons 2 "' .. .. .. ..Pumice ..... ................ ..... ...... short tons 35,000 t,245 79 4,612 W WSand and gravel:

Construction ...... thousand short tons 141,946 622,074 £138,300 £670,800 127,200 623.200Industrial ............ thousand short Ions 2,444 42,078 2,426 43.863 2,400 45.500

'Silvel ............ .... _. ..... ........ metric Ions 15 3,148 21 3,650 18 2,894Stone:

Crushed .... ........ thousand short tons £49,100 £275,000 54,887 238,034 44,000 200,600Dimension .... ..................... short tons E42,048 £5.991 28,829 5,564 30,077 5,213

Combined value of asbestos, barite (1988), calcium chloride (natural) (1988·89), copper, diatomite, feldspar, iron ore(includes byproduct material), magnesium compounds, mercury, molybdenum, perlite, potash, rare'earth metal concentrates.salt soda ash, sodium sulfate (natural), talc and prophyllite, titanium concentrates (ilmenite, 1989), tungsten ore concentrates,and values indicated by symbol W .." .... XX 334,755 XX 369,468 XX 349.940

Total ........ .,... ., ........ ,.,....... ,.,... , ....""., XX 2,698,654 XX 2,854,206 XX 2,722.343

£Estimated. NA Not Available. W Withheld to avoid disclosing company proprietary data:value included with "Combined Value" figure. XX Not applicable,

'Production as measured by mine shipments, sales, or marketable production (including consumption by producers).

'Beginning with 1989 data reported in B203, 1988 data converted.

'Recoverable content of ores.

California Production

There are nearly 1.100 active minesin California that produce about $3 bil·lion in mineral products annually (Table1). Most of these mines (65 percent)are sand and gravel operations, 26 per~

cent are industrial mineral mines, and 9percent are metal mines (Rapp and oth­ers, 1990). These mines vary in size,type and quality of ore mined, and thenumber of people they employ. A fewof the minerals being mined are singleelements. such as gold, but the vast ma~jority are ores composed of chemicalcompounds.

Although the mining industry in Cali·fornia is not as large or influential asagriculture or manufacturing, it remainsone of the most essential. Our qualityof lile is directly tied to the minerals weproduce and consume. Our desire formineral products is voracious-Ameri~

cans consume more minerals per personthan nearly any other nationality (Table2: U.S. Bureau of Mines news release,1990). It is vital that a continual flow ofthese essential resources is supplied.

PAST PROBLEMS

For many, the subject of miningbrings to mind vast open pits, stripmines, and unsightly wasle piles respon­sible for massive environmental damageto groundwater and surface water bod­ies. This perception is. in large part,based on past unregulated mining opera­lions that bear lillie similarity to currentmining operations in California. Paslmining·associated problems from acidmine drainage, contamination by mer­cury, cadmium. and other heavy metalsin streams and lakes, and asbestos-con­taminated surface water runoff werecaused primarily by mines thaI had oper­ated and were left abandoned before the

adoption of laws and regulations con­trolling the disposal of mining wastes.

To mitigate past abuses and to helpprevent future environmental abuses, anextensive system of rigorous Federaland State laws have been enacted toregulate mining operations throughoutCalifornia,

SMARA

In 1975 the State Legislature passedthe Surface Mining and ReclamationAct (SMARA) requiring the reclamationof California's surface mines. Asamended in 1990 (Assembly BillAB3551), SMARA requires that all ac­tive mine owners inform the State annu­ally about the status of their operation.This landmark legislation is also de­signed to identify and protect mineralresources in areas where land-use con·flict is high. SMARA legislation requires

CAlIFQANIA GEOLOGY MARCH 1991

TABLE 2. ESTIMATED MINERAL CONSUMPTION FOR EACHAMERICAN BORN IN 1991. Adapted from a U.S. Bureau ofMines news release.

Each American requires 20 tons of freshly mined non-fuelminerals each year. At this rate of consumption. a babyborn in 1991 will require during his or her lifetime:

.1.238.101 pounds of sand and gravel to make con­crete for building homes. schools. offices. factories.bridges, and roads

• 32.700 pounds of iron to make house appliances andkitchen utensils. cars, ships. and buildings

• 28,213 pounds of salt for making plastic products,detergents. water softeners, and for preparing foods

• 26.550 pounds of clay for making bricks. paper. paint.glass. and pollery

• 3,593 pounds of aluminum for beverage cans, houseSiding, aluminum foil, and as an alloy to make pipes.steam irons. motors, cookware, ladders. furniture.aircraft. and barbed wire

• 1.500 pounds of copper primarily used in electricmotors. generators. communications equipment, andin electric wiring

• 795 pounds of lead primarily used for car batleries.electronic components. and solder

• 757 pounds of zinc for protective coatings on steel, foruse in chemical compounds to make rubber and paint.and as an alloy with copper to make brass

MLRP

The Division of Mines and Geology's MinedLand Reclamation Project (MLRP) provides techni­cal assistance to federal. state. and local govern­ments during the planning and review of reclama­tion plans. Specifically, MLRP staff assist localgovemments with revegetation. erosion control.slope stability, mining engineering, and hydrology.MLRP sponsors workshops on mined-land reclama­tion and prepares publications about mining recla­mation practices.

Planning and management of surface-mined ar­eas in California have significantly improved overthe past two decades. Planning for future surfacemining operations now includes reclamation plansfor the mined land during and after operationshave been completed. MLRP staff actively encour­age the implementation of phased reclamation pro­cedures as part of ongoing mining operations. It isintended that such planning will provide muchbroader uses for reclaimed mined areas.

Improved reclamation practices that rescil andrevegetate land as quickly as possible after an areais disturbed by mining can significantly limit erosionby water and wind. Such practices can reducesedimentation impacts to fish and wildlife habitats.Because a permanent vegetative cover usually pro­vides the most cost effective and efficient meansfor stabilizing mined areas. a considerable amountof research has been conducted to determine what

that an inventory be compiled of allknown mineral deposits. and that anevaluation be made of areas where min­eralization is likely. SMARA mineral in­vestigations supply objective informationand are used to reduce conflict in minepermitting decisions at local planninghearings.

p 'r.-:" ')1 •.:-:. ••'!'- ••f

~ia .. " ••

Mud Hills zeolite mine, in the Mud Hillsabout 9 miles north of Barstow. San Ber­nardino County. Processed ore at the bot­tom of the pit is slacked and ready fortransport, The principal zeolite mineralmined is clinoptilolite. a potassium-richmineral that formed from the decompoSI­tion of basic volcanic rocks. Zeolites are agroup of aluminum-siticate minerals con­taining water that is easily expelled onhealing. The origin of the name zeolite isderived from lhe Greek word zein mean­ing. "to boil: Natural and synthetic zeoliteminerals have become important in recentyears because of their ability to remove ra­dioactive isotopes from nuclear waste ma·lerials. Photo byaurhor.

I I,.,

CALIFORNIA GEOLOGY MARCH 1991

Surface operations at the Sil(teen-To-One gold mme In the Allegheny dlStnct, southwestern Sierra Cou",y. First developed inlhe early 19OOs, this productive mIne IS one of lhe few underground mmes operalJng In California. Photo by John Bumen.

methods can be used for vegetating dis­turbed mined areas throughout Califor­nia California has great variations insoil types, climates, and plant communi·ties Detailed information is now avail·ab'e to successfully grow vegetative coY"ers 0'Jef most mined areas.

Desirable plant species used to re-­wgetate seriously disturbed mined areasare commonly chosen from varietK!sthat are native to a specific mine local­ity. Rewgetation programs can {II in·crease groundwater infiltration, (2) stabi·lize the soil. and (3) improve the habitatand appearance of previously minedsites. Successfully established plantsthat are tailor·fitted to the site can pro­vide continuing erosion protection withlittle or no maintenance. Unlike mined·ravaged areas in the 1800s. effectively

reclaimed mined areas in California arenow used for a variety of purposes thatinclude agriculture. recreation. industry.and urban development

CONCLUSION

Mining dates back to the earlieststages of human history and is-in largepart-responsible for the grov.rth of civili­zation 10e history and growth of Cali­fornia is directly tted to the developmentof gokl mining. With advances in recla­mation and mining technology. the ad­verse environmental affects from miningoperatoos will continue to be reduced.California's mineral production and thequality of life afforded us by these miner·als is impressive. It is important that acontinued now of reasonably pricedabundant minerals be sustained.

REFERENCES

American MIning Congress, 1972, Whatmining means to Itle Unrted States. 22 p

Fay, J.S" Fay, S.W., Boehm, R.J.. 1991,Ca~lorl'll3 Almanac. filth edillOn: PaoflcData Resources, p. 469-484

KefVledy. Harold, 1990, Feeding the~phosphate rock; U.S.Department ol theInt8flOf Bureau ol MIf"I8S, MInerals Today,p.6·'0.

McGraw-HI. Encyclopedia ol Soence &Technology, 1987. Sil(th editlOOMcGraw·HtI Book Company, v 7. p 2J6.23.

Rapp, JS, Sliva, M.A.. HlQgms, CT, Maron,RC., and Burnell, J.L, 1990. MInes andmmeral producers active tn Calitomla,1988·1989 DIviSIOn of Mtnes and Geot·ogy Special Publication 103. 162 p.

CALIFORNIA GEOlOGY MARCH 1991 "

MINERALS AND NUTRITION

..

Minerals used in agricultural fertilizers are essentialto maintain the il"lO"eaSed food pro::luction

needed by our expanding population. Plants requiremany elements to grow. Oxygen and hydrogen (bothderived from water) combined \lltth carbon (derivedfrom atmospheric carbon dioxide) make up 98 per­cent of the bulk of IMng plants. Hov.oever, nirrogen.phosphorous, potassium. cak:lurn. sulfur. and sewraIotheT minerals are also essential and are applied tosoils in the form of fertilizers; many of these basicplant minerals are mined.

Uke plants. minerals are also essential for humannutritional health. Most of us are aware thai iron. p0­

tassium. phosphorous. sodium, and cak:.ium are essen­tJaI minerals for our nutritional health. However,trace amounts of zinc. tin. rnoIybdenum. manganese.magnesium. cobalt, copper. chromium. vanadium.selenium, arxl others aTe also necessary. Most of themineral supplements added to food and medicines aremined. For example. supplemental iron has beenadded to flour and other cereal grains since 194 1(McGraw-Hill Encyclopedia of Science & Technology.p. 237·239). The following list illustrates the nutri­tional importance of a few selected minerals (Adaptedfrom Kennedy. 1990).

Phosphorus: A key ingred;ent in modem, manu­factured fertilizer. phosphate rock is rich in phospho­rus, an element required by every fonn of life onEarth Plants require phosphorus to grow and repro­duce, For animals and humans, phosphorus is neces­sary for the fonnation and function of bones. brain,blood, and tissues.

Phosphorus in phosphate rock is only one of morethan two dozen minerai-related elements thai play anessential role In prov\ding nutritton for humans, Ithelps nourish plants that in tum are eaten by animalsand humans.

Potauhun: Potassium, or potash, is the third keycomponent of fertilizer. Potassium akis the synthesisof starch and sugars in aU plants. It also helps plants

CAlIFORNIA GEOlOGY

withstand disease and harsh INeather. For humans,potassium assists In muscle contraction and in main­taining fluid and electrolyte balance in body ceUs.Potassium is also very imJX»1ant in sending nerveimpulses, as well as releasing energy from protein,fat, and carbohydrates.

Ca&cium: 1lIe filth most abundant clement in theEarth's crust, calcium builds bones and teeth and helpsmaintain bone strength. Calcium is also used inmuscle contraction, bkxxl clotting, and maintenanceof cell membranes Calcium is used in the prepara­tion of vitamin B and in numerous food supplements.

Copper: Best known for its industrial uses as ametal. copper Is also II necessary Ingredient in thehuman dMlt. It is required for the formation of hem0­globin, and It helps keep bones. bkxxl vessels. andnerves healthy.

Iron: A ma;or pan of the world's industrial base,iron Is also an essential human nutrient. It functionsprimarily as a carrier of oxygen in the body: as part ofhemoglobin In the blood and myoglobin in themuscles.

Magnesium: Best known perhaps for its functionas an alloy with aluminum to prcxluce beverage cans,magnesium is used In building bones. manufacturingproteins, releasing energy from muscle cells. and regu­lallng body temperature.

Zinc: Used for hundreds of years 10 produce alloyssuch as brass. zinc also plays an important role in theformation of protein In the body. It assists in woundhealing, blood fonnation, and general growth andmaintenance of all tissues. Zinc is a component ofmany enzymes and thus is involved in most metabolicprocesses.

Molybdenum. Selenium• • 00 Cobah: Neces­sary in trace amounts. these minerals act as catalystsin many essential metabolic reactions.~

MARCH 199\

• • • • • Book Reviews • • • • •Books re\llewe<! in Ihis section are not available for purchase from DMG.

$300

$300

$600

... 005500

$15,00

Pnce ,ncludesposlage and sales tax

eight tour stops: (1) the Nevada County His­torical Society Mining Museum, (2) the GoklDiscovery Marker, (3) Ihe Empire Mine StateHistoric Park. (4) the New Brunswick mine,(5) the Idaho-Maryland mine. (6) Yuba canalbuilding. Ott's assay office. and the GhldolliGold Exhibit. (7) Nevada Union High School.~nd IS) Gilmore F1ymg FIeld A general loca­tion map and specHlc discriplions of eachtour SlOP are included. In addiTion 10 thesestops. other optional stops and lheir descrip­tions Include the Red Dog. You Bel. andGreenhom hydraulic pits. the Malakoff o.g­gings State Park. the Nanh STar mine. andthe National Hotel in NCllada City, A glos­sary of mining tenns is Included

lodlCale number 01 copies~

SPECIAL REPORTSSRSS Fral'lOSCan dlertln California concrele aggregale 1959 .SR69 Clay rl'Hnerals ,n the playa sediments 0' the Motave Desert. Inyo, I<arn.

Los Angeles, aod San BernardinO counties. Cabtornoa 1961.SA70 Sand aod gravel resources Ollhe I<ern R,ver near Bakers/ield. I<ern CoUrtly.

Cahtornoa t961 .. ,_, $3,00SR91 Sllort contribul'ons to CALIFORNIA GEOLOGY Petrography 01 the s,x granot'c

inlfUsive un<ts ,n the YOSBfT\lle Valley area; The plulonlC and melamorphIC rocks0' the Ben Lomond Mountain area. Sanla Cruz County; The orig,n 01 TuscanBunes and the volume 01 the Tuscan Founatlon in northern CaIlIOf,..a:Chmenoen earthquake 01 Seplember 14. 1963; NOles on the types 01 Caldorn,a$p&ClBS oIlhe 'Ofam,noleral genus OrTtloka,s,ania die/nell. 1935. 1967

SR10l Trace elements In the Plumas copper ben. Plumas Counly. Calitorn,a 1971SRl2QGeology'lX plaMlrlg in Sonoma County. Call1om,a 1980SR125 M'nes and ""nelal depoSlls in Death Valley NatlOflal Monument

(Inyo and San Bernard'flQ counties). California 1976

several sites in this area that ulterest visitors,The Empire Mine State Historic Park offersvisitors an opportumty to tour an 800 acrearea that contains numerous mimng equip­ment. a partially opened mine shall. andpreserved mining buildings, More than sixmillion ounces of gold were produced fromthis single mine The Empire mine had 367miles of tunnels. some of which were morethan a mile deep. Nearby this historic mineis the Nevooa County Historical SocietyMining Museum that houses lhe largest reomaining Pelion wheel. old-lime mining pho­tos. a five-foot diameter drill core, and nu'merous mining equipment such as stampmnls. ore skips. mercury table, dynamitetable. and drilling tools This tour guide has

r----------------------------MAIL ORDER FORMComplete address form on next page

Mineralogy

MECHANICAL AcnVATION OF MIN­ERALS BY GRINDING, Pulverizing andmorphology of particles. By A,Z. Juhaszand L Opoczky. 1990. Available from:John Wiley & Sons. Inc.. 605 Third Ave­nue. New York. NY 10158. 234 p.$71.50. hard cover Price does not includesales lax. shipping. and handling.

Advances in Ihe technology of fine grind·ing aTe increasingly important for many in­dustries Aoe grinding involves physical andchemical changes thai affect the propertiesof materials and produces effects that can­not be adequately explained by the rerluclionin partide size only. The phenomenon offine grinding allers both the surface of themate~l and its cryslal1lne properties. Thistechnical book discusses the structural andchemical transformations produced by themechanical effects of grinding. Althoughthe pnme consideration in this book is aboutsilicates. other materials are also discussedOne important aspect of grinding technol­ogy is the reduction 01 materials made smallenough to make them more soluble An­other important aspect of this grinding tech­nology is to comprehend the changes incrystallonns that resull from the millingaction, Chemical changes also occur whencertain materials are reduced to a very linepower For example. when limestone isfinely ground as much as 40 percent of thecarbon dioxide locked within the limestoneis released; this aspect is an important con­sider"lion when making portland cementAnother example of a chemical change in­duced by grinding would be to grind ~inc

oxide in an atmosphere of carbon dioKide toproduce zinc carbonate.

L .

SPECIAL PUBLICATIONSSP66 The 1983 Coahnga (F,esno County). Calltorrtla earthqualles 1984 ,..... $12.00SP78 Earthquake plannong scenaflQ lor a magnotude 7 5 earthquake 0f1 the

Haywa,d rault in the San FraflClSCO Bay e'ea. Cal,forn,a 1987 530,00SP99 Planfllrlg SC8flano 10' a maJOr earT/lquake on the Newport·lnglewood faul! ZOf1e

(Los Angeles and Oranges count'es. Cali/erma) 1988 $2200SP109 Geolog-oc: eXQlfSlQf1S in flQrThern Cahfoffl,a; San F,arosco 10 the

S,erra Nevada. t99t (NEW) 510,00

Mining History

A SElF·GUIDED TOUR OF THEGRASS VAu.EY-NEVADA CITY MINESITES By FD Calhoon, 1978 AVClilabiefrom Bonded Book Buyers Bureau. 2300Wall Avenue. East Nicolaus. CA 95622. 50p. 5,00 Price includes sales tax, postage.and handling. Paper cover

Gokl mining In the Grass Valley-Ne­vada City area was an important industrythat lasted for more than 100 years. Therole mat mining played in this area was sig­nificant The last gold-mining operatiOnS inthis area were those of the Empire-Star andIdaho-Maryland groups: both of whichceased operations in 1956 There remain

CALIFORNIA GEOLOGY1 year {12,ssues)2 years (24 ISsues)Eac/l back 'SSll9

SpecIfy volume aod month.

lISl 01 Ava,lable PubilCalions.

TOTAL AMOUNT ENCLOSED

PAYMENT MUST BE INCLUDED WITH ORDER

$

510.00521),005U5

F,"

CAUFQflNIA GEOLOGY MARCH 1991 "

• • • • • • • • • • more books • • • • • • • • • •

, NEW SUBSCRIPTION: Allow 60 days lor delivery of first issue.

CALIFORNIA GEOLOGY SUBSCRIPTIONS

TOTAL AMOUNT ENCLOSED: $, _

, GIFT: (Gill card Irom _

MEMORIALQuintin Albert Aune

1924·1991

Quintin Aune. staff geologist Uliththe Division of Mines and Geologyfrom 1957 to 1980, died at hishome on January 9,1991. Quintinspecialized in clay minerals Investiga­tions while he was employed by theU.S. Bureau of Mines from 1954­1957. When he was first hired bythe Division of Mines and Geologyhe worked on the Alturas 1 by 2'geologic sheet of the state geologicmap series published by the Division.Throughout his career with the Divi­sion he I.U()rked on numerous projectsand contributed several articles toMinerals Information Service andCAUFORNJA GEOLOGY. A singleman his enUre life, Quinlin spon­sored and supported the education of25 children through the Catholic Mis­sionary Schools program in GundaJa.India from 1964-1991.x

only how to understand geologic maps, butalso how to coostNCt them for themselves.Nearly all of the examples provided aretaken from real maps that were derivedfrom real situations around the Earth.lllere is extensive use of three-dimensionaldiagrams and colored maps to illustrateconcepts. Selected chaplers within thistext include: fundamentals of geologicmaps. three-dimensional aspects of ge0­

logic maps-stNCturai contours. strike anddip, fonnation thickness and depth--geo­logic cross sections. fundamentals of faults,fokls, and unconformities, establishing thegeologic history from maps. mapping igne·ous and metamorphic rocks, and currenttrends in geological mapping. Each chap­ler includes an extensive description ofconcepts and the examples presented.This book explains geologic maps andhow to interpret them in a step·by-stepapproach without the c'YPtic mystificationpresented in other texts on the sub)ed,x

(Individual issues are $1.25 each)

GEOLOGICAL MAPS: An lnlrodllClion.By Alex Mailman. 1990. A~ilable from:Van Nostrand Reinhold. 7625 EmpireDrive, Florence. KY 41042.184 p.$49.95, hard cover.

Geologic maps derived from field dataand their interpretation are fundamentaltools of geologists. Rock pallerns derivedfrom such maps provide relationships andinsights into their geological history. Ge0­logic maps are also an effective way 01 com­municating new data to other geologists.Being able to interpret these patterns is anessential skill for beginning geology students.Because geologic maps are themselvesbased on interpretations. the completedmap directly reflects how well the geology01 an area is Wlderstood. This book is con'cerned with the fundamental principles ofgeologic mapping and is designed to be aself-gulding help in developing interpretiveskills. Geology students need to know not

EXPIA. DATE ACCT.••__---,=

, 2 yrs. $20.00, 1 yr. $10.00

I.D.• _

, ADDRESS CHANGE: Send us an old address label and your new address.Allow 60 days lor address change.

f1 RENEWAL: To receive your magazine continuously, send 10 renewal 60 days beloreexpiration date shown on your address label. (Example: EXP9112 meansthat the subscription expires on recelpl of December 1991 issue.) Pleaseenclose address label from pasl issue. Without an address label. renewalsubscriptions will take 3 to 4 months to process.

CALIFORNIA GEOLOGY .enew. only iii In InformatIon from your rtl8J~ng label OfIltlaCh a labelfrom a past issue.

Structural Geology

AN lNTRODUcnON TO GEOLOGI­CAL STRUcruRES AND MAPS. Fifth edi­tion. By C.M. Bennison. 1990. Availablefrom: Routledge. Chapman & Hall. 29thWest 35th Street, New York. N.Y. 10001.70 p. $9.95, soft COYeI'.

The fundamental evidence of geologicscience Is based on field OOselVations. Fieldmapping and interpretation are indispen­sable aspects of this discipline. This book isprimarily designed for geology students touse in correlation with geological mappingin lhe field. Each lopic is simply explained<'Inc:! illustrated with lext figures. Map exer­cises aTe given in a step-by-step approachand gradually become increasingly difficult.This book familiarixes lhe student with geo­logie mapping terminology. map symbols.and techniques for interpreting geologicstructures gathered on maps from field dala.Answers to map exercises are given at theend of the book.

STATE ZIP _

ADDRESS 1

CITY _

----------------------------,ADDRESS FORM FOR ALL ORDERS

Please print or Iype

PAYMENT MUST BE INCLUDED WITH ORDER

NAME ========-

IIIIIIII

Your order subscription cannot be processed unless COllect amount IS rerruned All fore'On and Cana- IdIan orders must be poilld Wlth an Internatronal Money Order or Drall payable In UMed Slates funds toDIVISIon of M,nes and Geology Address all orders 10 DIVISION Of MINES AND GEOLOGY. Pol

, ~~80. ~amento,~I~n~~:,,298~ ~

70 CALIfORNIA GEOLOGY MARCH t991

A Page for Teachers

2. Minerals are solid substances that occur nalUral1y in the Earth.

1. Minerals are inorganic. which means they usuully do not form from lheremains of plants. animals. or other living things,

Mineralogists have discovered CAler 2,500 different minerals: fewer than 100are common. and only 15 make up about 90 percent of the Earth's crust.

Gold was chosen as california's SlaleMineral because 01 the discovery 01 thisprecious metal at Coloma in 1848. Thisdiscovery led to the gold rush that playedan important role in the history 01 Calilor~

nia. The pictured Golden Bear Nuggetwas found in 1857 at the Georgia Hillmine in Yankee Jims. Placer County. Itweighs 1 ounce 19.2 grams troy. The tri­angular pa"ern on the 5urface is made upof gold crystals. The nugget is on displayat the Los Angeles County Museum ofNafural History in Exposition Parll., losAngeles. DMG Photo File.

y ou and your students can use thefollowing references to read more

about minerals.

• Magnetite is permanently magnetizedand allracts iron filings and other metal·lie objects such as paper clips.

• 1he mystery of how a bird migratesmay have been solved. It is thoughtthat a Iiny magnetic crystal in its braindetects the Earth's magnetic fie'd.

• Seventy-four minerals were firstfound and described in California.

Minerals

Minerals are made up of one or more chemical elements. (Elements are sub­SlanCe5 thllt cannol be broken down chemically into other. simpler substances;oxygen is an example.) Eighty-eight elements occur naturally on Earth. Mineralsmust fit into these four general criteria.

4. The atoms that make up a mineral are bonded in a specific repeating pattern.(An atom is the smallest unit of an elemenl.) This orderly arrangement of elementsis what forms a minerct's charllcteristic crystal shape. For example. a crystal ofhalite (table salt). which is made up of the elements sodium and chlorine. is alwayscube·shaped because the two kinds of atoms are "stackedMalternately in a boxlikefonn.

• California ranks number one indiversity of mineral commodities pro­duced. and number one in the produc­tion of more individual mineral com­modities than any other state.

3. Minerals have the same chemical makeup wherever they are found. For ex­ample. the mineral quartz always consists of one part silicon (an element) to twoparts oxygen (another element). Some minerals. such as gold. copper. and sulphur(called Mnative minerals") are made up of just that element. But most minerals arecomblnaUons of several different elements.

Crystals by Ian F. Mercer: HarvardUniversity Press. 1990

Roadside Geology of NorthernC<tliromla by A. Art and D. Hyndman:Mountain Press Publishing Company(Missoula. Montana). 1975.

Album of Rocks and Minerals byTom McGowan; Rand McNally. 1981.

Rocks and Minerals by RobinKerrod: Walts. 1981.

Gemstones by Chrlstme Woodwardand Dr. Roger Harding: Sterling Pub­lishing Co.. Inc.. 1988.

Rocks and Minerals by Herbertlim and Paul Schaffer; Western. 1957.

Rocks and Minerals of Californiaby Vinson Brown. 3rd edition:Naturgraph Publishers. 1972.";<'

DMG geologist, Cindy Pridmore, explains the wonders 01 minerals and losststo young children. Photo by Don Dupras.

CAUr-OANIA GEOLOGY MARCH 1991 "

STATE OF CAUFQRNIATHE RESOUfi:CES AGENCY

DEPARTMENT OF CONSfRVAllONCAUFORNlA GEOLOGY

DIVISION OfMINES AND Gf:Ol.OGY

POBOX 2980SACRAMENTO, CAlEORNIA 9.s812·2980

USPS 350 840

AOORfSS COi.llECnQN REQUESTED

SECOND ClASS POSTAGf: PAlOAT SACRAMENTO, CAlIfORNIA

• • • • Announcements • • • •

Fourth International Conferenceon Seismic Zonation

SMIP91 Seminaron Seismologicaland Engineering

Implications of RecentStrong-Motion Data

This seminar is designed to transferrecent research findings on strong~mo­

tion data to earth scientiSts and practiC­ing earthquake structure designers.Some of the topics include geologicaleffects on strong ground shaking. andthe response of base-i50laled structuresand unreinlorced masonry buildings dur­Ing the 1989 Lorna Prieta e"rthqu"ke.The seminar will be held Thursday. May30. 1991. at the Hilton Inn in Sacra-menlo.

For information on the seminar.contact,

California Department ofConservation

Division 01 Mines and GeologyOffice of Strong Malian StudIes630 Bercut Drive.Sacramento. CA 95814(916) 322-3105·...

TIle Earthquake Engineering Research Institute lEERt} is the sponsor forthis international conference to be heldon August 26 29. 1991 at StanfordUniversity. Stanford. California

The Fourth International Conferenceon Sei~mic Zonation is a major interna'tional event for reviewing and evaluating zonation relaled advances over thelast decade in eanh sciences. engineer­ing. urban planning. social sciences andpublic policy.

The conference 1Ni1l present multidis­ciplinary earthquake hazard mitigationefforts in major seisrTllc regiOns of theworld The program INiIl include:

(I) Invited state-of-the-dTt summariesdescribing recent advances lor seismiczonation in

• Earth Sciences• Engineering• Social Scienc(>~ and Public Policy

(2) Invited comprehensive case stud­ies describing methodologies for Im­

plementation of seismic zonation inAlgeria. Europe. Japan. Mexico. Chile.Peru. and the United States.

(3) Panel dlscus.~ions on future re­search and public policy needs related tozonation.

(4) Developments pertinent to seismiczonation. including results from recentearthquakes.

(5) Simultaneous sessions of submit·ted papers and posters.

An opening reception. luncheon.and banquet are planned as well as ex­cursions to San Francisco. Muir Wood:..Carmel. Monterey. Santa Clara. andother beautiful siTes. Conference partici­pants lind guests can also visit earth·quake enginC€ring and seismologyresearch facilities throughout the SanFrancisco Bay area.

For more informatron, contact;

4th Intemational Conference onSeismic Zonation

John A. BlumeEarthquake Engineering Center

Depanment of Civil EngineeringStanford UniversityStanlord, CA 94305-4020x

CALIFORNIA GEOLOGY MARCH 1991