guidelines for u.s. database and map

7/27/2019 Guidelines for U.S. Database and Map

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U.S. DEPARTMENT OF THE INTERIORU.S. GEOLOGICAL S URVEY

Maps of Ma jor Active Faults, Western HemisphereInternational Lithosphere Program (ILP)

Project 1 1 - 2Guidelines fo r U.S. Database and Map

June 1993by

Kathleen M. Haller 1 ,Michael N. Machette 1 ,and Richard L . Dart 1

Open-File Report 93-338

This report is preliminary and has not been reviewed fo r conformity with U.S. Geological Survey editorialstandards (o r with th e North American Stratigraphic Code). Any use of t rade, product, or firm names is fo rdescr ipt ive purposes only and does not imply endorsement by th e U.S. Government.These guidel ines are a working document that is cont inual ly under revision. It provides a basis forsystematically col lect ing data and compil ing maps o f active fault and fold structures. Updated versions o fth e guidel ine ca n be obtained f rom the authors, on paper or on computer disk.1 Box 25046, MS 966Denver, Colorado 80225U.S.A. 1993


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Table of contentsIntrod uc tion..................................................................................................................................... 1Alphabetic definition of term s..........................................................................................................3

Terms fo r stru ctu res...........................................................................................................3Terms fo r historical surface fau lting..................................................................................10

Showing structural features on your m ap ......................................................................................12Compilat ion form fo r segmented fau lts..........................................................................................15Example of data fo r segmented fau lt.............................................................................................17Compilat ion form fo r sectioned fau lts ............................................................................................29Example of data fo r sectioned fault ...............................................................................................31Compilat ion form fo r simple fau lts.................................................................................................39Example of data fo r simple fault ....................................................................................................41Compilat ion form fo r historical surface fau lting..............................................................................43Example of data fo r historical surface faul t ing earthquake ............................................................44

FiguresFigure 1. Key to Fennem an's physical divis ions o f th e United States.......................................... 6Figure 2. Example of compiled m ap ............................................................................................14


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IntroductionAs part of the Internat ional Lithosphere Program's "World Map of Major Active Faults," we are

compiling a series of digital maps fo r the United States that will show the locations, ages, and activityrates of major earthquake-related features such as faults and fault-related folds, and a relational databasethat describes these features. The United States part of the project was started in 1992 and should becompleted by th e end of 1995 with the coop eration of state and regional participants. The project is a keypart of th e ne w Global Seismic Hazards Assessment Program (ILP Project II-O) fo r th e InternationalDecade fo r Natural Hazard Disaster Reduction.

Th e purpose of this guideline is to provide a uniform description of terms so that compilers ca n enterdata on Quaternary faulting and folding into the catalog (database) in a systematic manner. Technicalterms and data fields are described in alphabetical order and examples o f usage and format are given.Some items in th e alphabetic listing are grouped by general name, whereas terms that apply to "HistoricalSurface Faulting" are listed in the following section.

When you enter information on a database form, be brief and to the point. Write in an abbreviatedstyle whenever possible. We don't care if sentences are complete just that the information is complete.The type of information that should be included under each item is shown in italics. Many items have acomment section that can be used fo r explanatory notes.

Each compiler will be responsible fo r including a complete se t of references (see "References" in nextsection); it will be our job to compile the final list of references. W e request a photocop y of the title/coverpage of all references that you use in order to properly format the references; please make sure that al lpertinent information is contained on th e photocopy, including range or number of pages, editors, volumename, etc.

Compilat ions such as this provide a powerful tool fo r making comparisons of spat ial and temporalpatterns of fau lting at local, regional, and national scales. However, a database is powerful only if it is asystematic collection of data one that presents fact and no t interpretation on the part of the compiler.With this in mind, th e compiler should strive to reference al l data as co mpletely as possible, to include al lpertinent data (especially where conflicts may be apparent), and to select th e most appropriate data toinclude. To determine what data should be included, give preference to (1 ) fault-related topical studiesover general studies (i.e., those addressing paleoseismology versus general geology), (2) more recentstudies, and (3 ) more detailed scale of work (i.e., 1:24,000-scale over 1:250,000-scale mapping). Someexceptions to these rules will occur, but general ly one should give th e most weight to recent topicalstudies of Q uaternary fault ing.

The com piler will have to make educated (but qualif ied) guesses fo r certain entries in th e database.For example, the digital map requires that each fault and fold have a number, name (given or "Unnamedfault"), line type, sense of movement, slip rate, and t ime of most recent movement. W e will provide a setof numbers to each compiler to assign to their structures (see "Number" in next section). Nam es will bedetermined by th e literature and common usage. Line types will be either solid, dashed, or dotted,


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INTRODUCTION

depending on the continui ty or surface expression of th e mapped structure (see section on "How to showstructural features on your map") . Slip rate and t ime o f most recent movem ent will each be selected f romone o f th e designated categories, which will provide a basis for dividing younger active structures f romolder less active structures on th e map. The compi ler is forced to select a slip rate and age even when nodata m ay exist. In th e case o f slip rates, you may choose "unknown", but must further qualify this withyour best guess. For examp le, a normal fault that does not cut Holocene (


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Alphabet ic definition of t e r msDescriptions of terms are provided in i talics. Examples are fo r illustration only, but provide guidance

fo r style and content. The types of information that should be d iscussed in the "Comments" sections aredescribed fo r each case, where appropriate. Bold i tems ca n be found on the compilation forms. Unlessotherwise noted, the following terms will appear on all three forms (simple, section, segment). Itemspertaining only to "Historical Surface Faulting" are defined in the next section. Data fo r folds should becompiled following the examples fo r faults: instead of slip rate, uplift rate may be substituted.Terms for structuresA ge of faulted (o r folded) surficial deposits This sect ion should inc lude th e ages of faul ted deposi ts 1th e surface. List deposi ts from younges t to oldest. Don' t be tempted to guess th e a ge of deposi ts;document only data from referenced sources. In addi t ion, an est imate of the ex tent of th e faul t that is ina part icu lar age of deposi t might be informative.

Example: Quaternary alluvium, colluvium, and glacial deposits (90%); Paleozoic-Mesozoic andPrecambrian bedrock (10%) (Personius, 1982a). Much of the length of th e fault probably extendsthrough late Quaternary deposits but scarps are not preserved in many locations (these sections of th efault are designated Quaternary).Average strike (azimuth) Determined f rom G IS data, l eave blankCompiler and affi l iat ion

Example: Michael J. Stickney, Montana Bureau o f Mines and GeologyCounty Spel l ou t full county name; if more than one county, l is t cou nty in which the majori ty of th estructure is located, fol lowed by county name(s) fo r th e remainder of th e structure.

Example: Jefferson; ButteDate of co mpi lat ion Give date that the data were compi led fo r this project (this wil l help us keep th einformat ion cur rent ) . FOR MAT : mm/dd/yr

E x a m p l e : 08/19/93Detailed studies This i tem is reserved fo r studies such as t renching. Documentat ion sh ould fo llow theexample given below. Number th e study si tes sequential ly from north to south in th e format of faul tnumber, segment o r sect ion letter, a nd site number (i.e., 601 C-3) . Inc lude references a nd a synops is ofth e work. Reserve appropr iate paleoseismic data fo r discussions of recurrence interval, slip rate, a ndt iming of most recen t paleoevent.

Example: Four trenches and another excavation, which did no t cross the fault, have been excavated onth e Thousand Springs segment. No datable material was recovered at any of these sites. One and insome cases tw o prehistorical events were recognized. Many of the prehistorical structures werereactivated in 1983 in terms of style an d amount o f displacement (Crone, 1985; Schwartz and Crone,1985). These studies concentrated on the West Spring, Doublespring Pass road, and Rock Creekareas.West Spring. Trench 601C-1 about 0.8 km northwest of West Spring was excavated by Cochran in1984? (Cochran, 1985).Doublespring Pass road. The earliest trench (601C-2) on this segment was excavated by Hait in 1976and p redates the 1983 Borah Peak earthqu ake. This site (601 C-3) was re-excavated by Schwartz andCrone in 1984 following the earthquake. Both trenches, which are documented in Crone (1985), wereabout 65 m northwest of Doublespring Pass road, which is north of the middle of the segment. Another


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ALPHABETIC DEFINITION OF TERMS

trench excavated in 1984 by Schwar tz and Crone is 0.5 km southeast of Doublespr ing Pass road(601C-4) (Crone, 1985; Schwartz and Crone, 1985). Although it was not logged, stratigraphic relationssuggest tw o prehistorical events (Crone, oral comm., 1993).Rock Creek. Excavation 601C-5, about 250 m northwest of Rock Creek access road, by Cochran in1984? did no t cross the fault but contained Ma zama ash (about 6,700 yr), which provides a maximumlimit ing age because of its position in colluvial section (Cochran, 1985). Three faul t ing events,including 1983, are inferred since 40 ka , but results are preliminary and 40-ka l imiting age is notsubstantiated by numerical dat ing methods.

Dip Ente r mea su r ed va lue or r a nge and d ip direct ion. F o r d ip mea su r emen ts at spec i fic po in ts , s h o wloca t ion o n m a p a n d l abe l so it ca n b e digit ized for la t i tude and longitude. If the va lue c o m e s fromtrench ing studies, it shou ld be inc luded here.Exa mple : 80 W . (Bonini and others, 1972); 60 W . (Personius, 1982a); 50 W . (Pardee, 1950)C o m m e n t s : Include th ings l ike app rox imate loca t ion a n d the type of ma te r ia l in which th e fau l t isexposed.Exa mple : Exact location o f 80 W . unknown, but probably from northernmost p art of fault thatPersonius (1982a) describes as in bedrock. Dip o f fault reported by Personius (1982a) is fromexposure of fault 4 km northeast o f Sixmile Canyon in unconsol idated al luvium. Pardee (1950) reportsd ip o f faul t in 6-m-deep art if icial exp osure probably in unconsol idated al luvium, exact locat ion unknownbut was somewhere along southernmost part o f fault. Vertical fault model provides best fit fo r gravitydata (Bonini and others, 1972).

D ip direct ion Enter genera l dip direct ion of th e structure Choice o f N, W , S, E, NW , N E, SW, SE ONLYEndpoin ts Dete r m ined from G I S d a t a , l ea ve b lankGeologic sett ing G ener a l s ta temen t a b o u t set t ing. Include a mou n ts of to ta l of fset a n d a g e if known .

Exa mple : High-angle, dow n-to-southwest, range-front normal fault, with m inor sinistral com ponent,bounding southwest side of Lost River Range. There m ay be as much as 6.1 km of late Cenozoicdisplacement across the fault (Skipp and Hart, 1977).Geomorph ic expression Descr ibe (i n genera l te rms) the st ructure 's geom orph ic express ion ( faultscarps , of fset s t reams, monoc l ines , sh u t te r r idges, a ssoc ia ted landsl ides, etc. )

Examp le : The Drum Mountain fault form s smal l (1-2 m) to moderate (


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N u m b e rStructure num ber Assign structure (faul t or fold) a number within th e l imits we provide.Comments: Inc lude appropriate references to features shown in other faul t compi lat ions.Exa mple : Refers to fault number 112 ("unnamed faul t") in Witkind (1975). OR- Refers to fault 116 and193 ("unnamed faul t") o f Witkind (1975) and fault 1 ("Lost River fault") of Stickney and Bar tho lomew(1987).Seg men t n u mber The number a ss igned here is th e faul t num ber a n d an upper-case alpha character.Assign "A" to th e nor thernmost o r westernmost segment of a faul t (i.e., faul t 305 has three segments :305A, 305B, 305C).Sect ion number The number ass igned here is th e faul t number a nd a lower-case a lpha character.Assign "a " to the nor thernmost o r westernmost se c t ion of a fault, (i.e., faul t 207 ha s three sec t ions :207a, 207b, 207c); use l ower case to differentiate from "segments" .

N u m b e r o f sect ions (for faults with sections only) Numer ic va lue fo r n u m b e r of sect ions (i.e., 4).Comments: (1) Include reference in which sect ions a re discussed, a nd (2 ) if th e term "se gme nt" isused in the l i terature, indicate why "sec t ion" i s used i n the database.Exa mple : Although numerous authors (Witkind, 1975a; Johns and others, 1982; Stickney andBartholomew, 1987) discuss segments o f th e Centennial fault, data are insufficient to defineseismogenic segments. O R: The parts of th e faul t discussed in detail are nearly continuous scarps o frestricted length that have similar characteristics as descr ibed by Personius (1982a). According toPerson!us (1982b), scarp-morphology data does no t allow definition of segmentation o f this fault, eventhough the faul t has an abrupt bend and left-stepping en echelon scarps in its central part which couldsuggest a possib le segment boundary. Segment names are given in Montana Bureau of Mines andGeology digital database (Stickney, written comm ., 1992), however, they have been abandoned fo ror iginal nomenclature o f Personius (1982a). Sections as defined here based on apparent change int iming of most recent faulting along strike; however, section boundary does not coincide with abruptchange in strike of fault that Personius (1982a) speculates could be a segment boundary.

Num ber of segments (for faults with segments only) A number shou ld appear here (i.e., 6) if recentstudies indicate structure is segmented; if not, use a different form. Minimum criteria fo r considering afaul t as segmented inc lude: 1 ) t renching on a ll segments, 2) histor ica l surface faul t ing rupturing only ap ar t of fault, or 3) t renching on a suff ic ient number of segments along with c lear morpholog icdifferences where t renching has not been done. M a n y authors use th e word "segment" in the i rdiscussions, but not in an se ismogenic sense. In a case such a s this, use the guidel ines fo r a "Faul twith sect ions" a n d address th e appa rent d iscrepancy in the nomenclature. If there are severa l modelsfo r segmentat ion, you wil l have to select a "preferred" model.Comments: Inc lude reference in which segmentat ion m od e l is discussed, a n d if there are severa lmodels fo r th e fault, provide a brief discussion of those models .Examp le : Detai led mapping and trenching has provided a basis fo r a model o f 10 segments along th eWasatch fault zone (Machette and others, 1991), whereas other segmentat ion models suggest thepresence o f 6-10 segments (Swan and Schwartz, 1980; Schwartz and Coppersmith, 1984) and asmany as 12 segments (Machette and others, 1986).

Province Use Fenneman's prov ince n am e s (see at tached map)


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ALPHABETIC DEFINITION O F TERMS

Fenneman's Phys ica l Divis ions o f the U ni ted Sta tes1 Superior Upland 14 Ozark Plateaus2 Continental Shelf (Atlantic) 15 Ouachita3 Coastal Plain (Atlantic) 16 Southern Rocky Mountains4 Piedmont 17 Wyoming Basin5 Blue Ridge 18 Middle Rocky Mountains6 Valley and Ridge 19 Northern Rocky Mountains7 St. Lawrence Valley 20 Colombia Plateaus8 Appalachian Plateaus 21 Colorado Plateaus9 New England 22 Basin and Range10 Adirondack 23 Cascade-Sierra Mountains1 1 Interior Lo w Plateaus 24 Pacific Border12 Central Lowland 25 Lower California13 Great Plains

Recurrence interval List in terva l in yr (based on histor ic data , calendric, or ca l ibra ted rad iocarbondates), in 14C yr ( ba sed on unca l ibra ted rad iocarbon dates), or in k.y. ( ba sed on less prec i se dat ing,s t ra t igraphy, or geomorpho logy) . Also inc lude th e t ime in terva l in pa r en th es is for which th is recur rencei n terva l is valid. N o t determined (ND) is a val id entry.E x a m p l e : 6-15 k.y. (


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ALPHABETIC DEFINITION O FT ER M S

Reliability o f location Choice of Good or PoorC o m m e n t s : Th is rel iabi l i ty refers to th e locat ion of the t race of th e structure. Include th e source a n dsca le of th e mapp in g . Note tha t t h ese j udgments of rel iabi l i ty a re separa te from th e m a p symbo ls(solid, dashe d , dotted) tha t w i l l be used.Go o d: (1 ) Sou r ce of t race of fault or fold is t ransfer red from ba se m a p at 1:250,000 (o r mor e detai led)with topograph ic (o r ba thymet r ic ) cont ro l and w as a ccu r a te ly loca ted o n or ig ina l map us in gph o tog r a mmet r y or s imi lar methods, or (2 ) source is m a p at 1:100,000 or mor e deta i led sca le o ntopograph ic (or ba thym et r ic ) ba se , but t ransfer red wi thout ph o tog r a mmet r i c methods.Examp le : Good. (1 ) Location of scarps based on 1:250,000-scale maps of Haller (1988); or iginalmapping at 1:24,000-62,500 scale, o r (2 ) Location o f scarps from 1:24,000 scale maps of Ostenna(1992), transferred to 1:100,000 by inspection.Poor: Less than a bove standards (smal ler sca le , plan imet r ic base, t ransfer by inspect ion, etc.). Allconcea led or inferred faul ts a re cons id e r ed poor l y located.Examp le : Poor. (1 ) Location of fault scarps based on 1:500,000-scale maps o f Witkind (1975), o r (2 )submar ine scarps f rom sea-beam-survey maps at 1:250,000 scale.

Sect ion name (see Name)Section n u m b e r (see Number)Segment name (see Name)Segment number (see Number)S e n s e o f m o v e m e n t Choice of T, R , D, S, or N. F o r combinat ions , s h o w pr inc ip le sense first.

T Thrust (5 mm /yr , 5- 1 mm/yr ,


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State Spe l l o u t full sta te n a m e ; if mor e t han one state, l ist sta te in which th e major i ty of th e structure islocated, fo l lowed by sta te n ame (s ) fo r th e r ema ind er of the st ructure.Exa mple : Montana; Idaho; Wyoming

Struc ture name (See Name)Structure n u m b e r (See Number)Synops is Prov ide a one or tw o sen tence synops is of faul t descr ib ing leve l of study. Th is wil l give readera s n a p s h o t of e v e l of data tha t fo l lows in the database .Examp le : Faul t is poor ly understood, no known studies have been completed at time of this compilat ion.Sole source of data is Wrtkind (1975b).Timing o f most recen t paleoevent ( faul t ing or folding) This is fo r pa leoevent only. If there is h is tor ica lfault ing or fo ld ing (ca tegory 1 ) , it wil l be d ea l t with in "H is to r ica l Sur face Fau l t ing" fo rm; data per ta in ingto th e penu l t ima te even t be longs here. C ho ice s are:

(2 ) Holocene and post glacial (


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Terms fo r historical surface faultingAffected structures), segm ent (s ), sec t ion (s ) num ber Lis t all features t h a t were af fec ted by sur facerupture. W h e n only a part of a faul t ruptured, l is t only those spec i fic segm ents or sections not th e fau l tnumber. Firs t numbe r shou ld be the pr imary sur face rupture, seco ndary ruptures sh ou ld fo l low.

E x a m p l e : 601C ; 601B , 601 g, 604b[Th ese r epr esen t th e af fec ted areas f rom th e B or a h P e a k ear thquake, Idaho, inc lud ing T h o u s a n dSpr ings (601 C) and W a r m Spr ing (601 B ) segments of th e L o s t River fau l t (601), Wil low C r e e k hillss t rand (601 g), andpart of the Lone Pine fault (604b). ]Date FORMAT: mm/dd/year . Inc lude ful l year to d iscr imina te f rom pre-1900's events .

Exa mple : 08/19/1954Depth of epicenter

Exa mple : 14-16 kmC o m m e n t s : U se for re ference a n d o th e r per t inent in format ionExample: Dewey (1985; 1987) reported 14 km, whereas 16 km w as reported by Doser and Smi th(1985) .

Dip S ee previous sect ionGeophys ica l average slip This is for amount (s) of mod e led sl ip.

Exa mple : 1.4-2.1 mC o m m e n t s : Include informat ion on type of data , locat ion, o t h e r qual i f icat ions.Example: Preferred model for geodet ic data (Barr ientos and others, 1987) indicates 2.1 m of slip atsouthern end o f rupture and 1.4 m o f slip at th e northern end of rupture on a single planar fau lt dipping49 SW with dimensions of 26 km long by 18 km (south end) to 8 km (north end) wide. Calculat ionsbased on th e se ismic mom ent su gges t 1 .4 m of s l ip (Dos er and S mi th, 1985) .

Length of surface rupture Determ ined f rom GIS data, leave b lankC o m m e n t s : D o c u m e n t pub l i shed lengths as t hey wil l l ikely differ f rom GIS lengths . W e wil l record G ISlengths s o t ha t t hey wil l be uniform in thei r por t raya l ; d if ferent au thors often use dif ferent meth od s todetermine this parameter , use c o m m e n t sec t ion to d ocu men t t h e ir f indings.Ex am p l e : 36.4 3.1 km reported by Crone and others (1987) ; length is not su m of trace lengths ofvarious parts o f rupture bu t is a straight-l ine length. They believe that the 20.8-km- long rupture onThousand Spr ings segment (601 C) represents the pr imary rupture and th e 7.9-km- long rupture onWa rm Spr ing segmen t (601 B) and 14.2 km on the nearby W i llow Creek hills strand (601 g) and LonePine fault (604b) are secondary result (triggered slip). Geod et ic data (Barr ientos and others, 1987)su ppor t this interpretat ion.

Locat ion of ep icenter Give la t i tude a n d longitude coord ina tes in d ec ima l d eg r eesExamp le : 43.974 N; 113 .916 WC o m m e n t s : U se for re ference a n d o th e r per t inent informat ionE x a m p l e : (Dewey, 1987) Epicenter was abou t 14 km south-southwest of termination of recognizedsur face fau lt ing. Rupture propa gated up and uni lateral ly to northwest , contrary to eyewitness report inWal lace (1984).

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ALPHABETIC DEFINITION O F TERMS

Magni tude o r in tensi ty Include type (M s , Mb, M w , Mi M c , etc. ) a n d va lueExa mple : MS -7. 3C o m m e n t s : U se fo r re ference and other pe r t inen t in fo rmat ionExa mple : (Dewey, 1987)

Maximum sl ip at surfaceExample: 2.7 mC o m m e n t s : Inc lude documenta t ion for type and locat ion of me asure me n t .Exa mple : Maximum is net vertical throw; average vertical throw along entire rupture 0.8 m; averagevertical throw along Thousand S pr ings segment (601C) 1 .1 m, 58% of length of rupture on ThousandSprings segment had scarps that exceeded 1 m in throw; left-lateral com ponen t was ap proximately17% o f vert ical (Crone and others, 1985; 1987). Some individual scarps are nearly 5 m high (Croneand Haller, 1991), but were associated with grabens and local backtil t ing.

M o m e n t magni tude (M ) o r S e i s m i c m o m e n t (M0 ) Include type, value, a n d un i ts (where appl icab le)Examp le : M = 6.0C o m m e n t s : U se fo r re ference and other pe r t inen t in fo rmat ionExa mple : (Ellsworth, 1990)

N a m e o f ear thquake See Name, previous sectionReferences See previous sect ionS e n s e o f m o v e m e n t S ee previous sect ion

1 1


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Showing structural features on your m a pPlease use the fol lowing guidel ines when yo u draft your map. W e will use your m ap to (1 ) digitize th e

features, (2 ) ascribe attr ibutes (age, slip rate, etc.) to the features, and (3 ) check against th e digitallyprepared map. Exa mples are fo r il lustration only but provide guidance fo r style and content. Six attr ibutes(structure number, name, t ime o f movement , slip-rate category, sense of movement, and l ine type) areneeded fo r th e digital m ap f i le as described in th e preceding section. In addit ion, we need to know th emap 's project ion and scale, and the author and date of th e compilat ion.Compi ler and date Indicate th e n a m e of th e compi le r a n d date of compi la t ion (month andyear isadequate) . If there a re mult iple compi le rs , ind ica te by region or a n o t h e r method.M ap scale and project ion Indicate th e sca le of t h e ma p ( no t crit ical), its pro ject ion (TransverseMercato r , A lbers , etc.), a n d ma ke su r e th a t there a re la t i tude a n d longitude t icks on th e borders a n din ternal ly. W e wil l use th e t ick marks and pro ject ion in fo rmat ion in th e G IS to prec isely loca te allstructures. Use th e b e s t a va i la b le ma p fo r your ba se : fo r the Uni ted Sta tes, w e are suggest ing A M S

m a p s wh ich have topograph ic cont ro l and a sca le of 1:250,000. Large sca le maps (1 :24,000 or1:25,000) ca n be used, bu t the d igita l f i les fo r e ach structure a re need les s ly la rge and detai led.R e m e m b e r t ha t th e even tu a l ou tpu t of the d ig i ta l map is d es igned fo r sta te and na t iona l sca le s(1:500,000 to 1:2,500,000).N u m b e r s

Structu re number Se lec t from preass igned n u m b e r l ist. Examp le : 111.S e g m e n t n u m b e r T h e nu mber a ss igned here is the fau lt num ber and a n u pper -ca se a lph a charac te r .Ass ign "A" to the nor th e r nmos t or we s t e rn mo s t s e g m e n t of th e fault. Examp le : 11 1 A.Sect ion n u m b e r T h e nu mber a ss igned he re is the faul t n u m b e r and a low er -ca se a lph a charac te r .Ass ign "a " to t h e no r th e rnmos t or w es te r nmos t sect ion of th e fault. Examp le : 111 a.

N a m e s U se the ear l ies t g iven nam e fora fault, fold, segment , sect ion (whe re appropr ia te ) , excep t inc a s e s whe re there is a mor e c o m m o n l y u sed na me in th e r ecen t l i terature.Structure n a m e Examples : Lost River fault, Wheeler Ridge anticlineS e g m e n t n a m e Example : Thousand S pr ings segmentSect ion name E xa mple : May section

Line types W e c a n use three dif ferent line types. Draw all l ines a s sol id, b u t m a r k the endpo in ts ofd a s h e d a n d dot ted l ines with a t ick mark . If a structure is not p resent at th e sur face (i.e., c o n c e a l e dthrust, bur ied Quaternary fault), then you sh ou ld sp ec i fy a dot ted l ine.Solid Character ized by nearly cont inuous features (scarps).

X) Dashed Character ized by discontinuous features where gaps are longer than mappablefeatures.O) Dotted Feature is concealed o r inferred from geologic o r geophysical data.

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S H OWI NG STRUCTURAL FEATURES ON Y OU R MAP

S e n s e o f m o v e m e n t S h o w on m a p with s y m b o l forpr inc ipa l sense of mot ion ; for combinat ions , a lsoinclude let ter designat ion with pr inc ip le sense first. A reverse r ight- la tera l st r ike sl ip fau l t with lessver t ica l t han hor izonta l s l ip wou ld be D R .T Thrust, teeth closely space on hanging wall blockR Reverse, teeth no t closely spaced on hanging wall blockD Dextral, right lateral arrowsS Sinistral, left lateral arrowsN Normal, bar and ball on hanging wall block

Slip rate C ho o se o n e of th e fo l lowing and code the l ine with th e appropr ia te letter. If th e rate isunknown, c h o o s e th e m ost l i ke ly rate b a s e d on geolog ic a n d geomor ph ic data .A) >5 mm /yrB ) 5- 1 m m / y rC) < 1 mm/yr

T i m e o f mo st recen t pa leoevent C ho o se one of th e fo l lowing a n d code the l ine with th e appropr ia tenum ber. In addit ion, to help us digit ize the features you may co lo r cod e the l ines as ind icated.1) Historic (year will be recorded in database), red.2) Holocene and post glacial (


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Hypothet ical faul ts, Van Horn sheet, Texas57 . Guadalupe Mountains normal fault

57a, Guadalupe section, Holocene (2), 1-5mm/yr(B) , solid line57b, Patterson Hills section, Late Quaternary(3), < 1 mm/yr (C), solid line

58. Unnamed normal fault, Late Quaternary (3),< 1 mm/yr (C), solid and dashed lines59 . Delaware Moun tains thrust/reverse fault,Holocene (2), 1-5 mm/yr (B), solid line60 . Unnamed thrust fault, Late or Middle Quaternary(4), < 1 mm/yr (C), solid line61 . Unnamed normal/dextral (ND) faults, LateQuaternary (3), < 1 mm/yr (C), dashed lines62 . Lynch Ranch dextral/normal (DN) faults,Holocene (2), 1-5 mm/yr (B), solid lines

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FIGURE 2. Example of compiled map14


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Comp i la t i on form for s e g m e n t e d faultsSTRUCTURE ATTRIBUTES

Struc ture nu mberComments:Structure nameComments:

Synopsis:Date o f compi lat ionCompiler and affi l iat ionStateCounty1x2sheetProvinceGeologic sett ingNumber of segments

Comments:Length (km) Determined from GIS dataAverage strike (azimuth) Determined from GIS dataEndpoints (lat. - long.) Determined from GIS data

SEGMENTATTRIBUTESSegment numberSegment name

Comments:Reliability of locat ion Good Poor

Comments:Sense of mov e me nt T R D S N

Comments:D ip

Comments:D ip directionGeom orphic expressionA ge o f faulted depositsDetai led studies

1 5


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COMPILATION FORM FO R SEGMENTED FAULTS

Timing o f most recent paleoevent CHOOSE ONE(2 ) Holocene and post glacial (


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E x a m p le of data fo r s e g m e n t e d faul tS E G M E N T E D F A UL T A T T R I B U T E S

Structure number 601Comments: Refers to faults 11 6 and 193 ("unnamed fault") of Witkind (1975) and fault 1 ("Lost Riverfault") of Stlckney an d Bartholomew (1987).

Structure n a m e Lost River faultComments: Baldwin (1951) recognized B asin-and-Range style fault ing in this area, as well as recentmovement and large amounts of throw across this and nearby faults. His 1951 article is probably oneo f earliest to use Lost River fault fo r this structure. Fault extends along entire length of southwest f lanko f Lost River Range.Synopsis: Extensive investigation of this long, range-front fault in central Idaho began after the 1983Borah Peak earthquake that resulted in surface rupture on 2 segments and a subsidiary strand of theLost River fault. Development of a segmentation model evolved from earthquake data and earliermapping of th e fault.Date of com pi lat ion 11/12/92Com pi ler and affiliation Kathleen M. Haller, U.S. Geological SurveyState IdahoCounty Custer; Butte1 x 2 sheet Dubois; Idaho Falls; ChallisProvince Northern Rocky MountainsGeologic sett ing High-angle, down-to-southwest, range-front normal fault, with minor sinistral

component, bounding southwest side of Lost River Range. There may be as much as 6.1 km of lateCenozoic displacement across the fault (Skipp and Hart, 1977).Number of segments 6Comm ents: Scott and others (1985) defined segmentation of Lost River fault an d is source of segmentnames except northernmost segment, which was renamed in Crone and others (1985; 1987) fo rconsistency. Scarps formed during Borah Peak earthquake across Willow Creek hills (601 g) areincluded as part of this fault.Length (km) Determined f romG IS dataAverage str ike (azimuth) Determined from GIS dataEndpoints (lat. - long.) Determined from GIS data

17


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EXAMPLE OF DATA FO R SEGMENTED FAULT

SEGMENT ATTRIBUTESSegment number 601ASegment name Challis segment

Comments: Also called Northern segment as defined by Scott and others (1985); was renamed Challissegment fo r consistency by Crone an d others (1985; 1987). Extends from the northern en d of LostRiver Range southeast to Devils Canyon.Reliability of location PoorComments: Location of fault generally based on topography, scarps on alluvium are absent. Source ofmap trace based on 1:24,000-scale maps of Crone (unpublished data).Sense o f m ov e m e n t NComments:D ipComments:D ip direction SWGeomorphic expression No scarps are on alluvium (Scott and others, 1985); local topography suggeststhe fault has at least tw o subparallel strands at south end of segment (Crone and Haller, 1991).A ge o f faulted depositsDetailed studiesTiming o f most recent paleoevent(5 ) Quaternary (


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Segment number 601BSegment name Warm Spring segmentComments: Defined and named by Scott and others (1985). Extends from Devils Canyon southeast toWil low Creek hills. Also shown as Gooseberry Creek segment in Montana Bureau o f Mines andGeology digital database (Stickney and Bartholomew, written commun. 1992).Reliability of location GoodComments: Location of scarps based on 1:24,000-scale maps of Crone and others (1985; 1987).Sense o f m ov e m e n t NComments:D ipComments:Dip direction SWGeomorphic expression Nearly continuous, morphologically young scarps, many of which were offsetless than 1 m in 1983 (Crone and others, 1987). Pre-1983 scarps are as much as 5.7 m high (CroneandHaller, 1991).Age of faulted depositsDetailed studiesTwo trenches 7.5 km apart have been excavated on th e Warm Spring segment. Trench 601B-1(Schwartz and Crone, 1988) on south side of an unnamed creek approximately 7 km south of northernsegm ent bou ndary. Trench 601B -2 (Schwartz and Crone, 1988) on south side of small drainageapproximately 2 km north of southern segment boundary.Timing o f m os t recent paleoevent(2 ) Holocene and post glacial (< 15 ka)Comm ents: Trenching studies (Schwartz and Crone, 1988) suggest one pre-1983 fault ing event in past12 k.y. that occurred prior to 5,200-6,200 14 C yr. Morphology of scarps that did no t rupture in 1983also suggests an age younger than pre-1983 scarps on Thousand S prings segment (601C, alsoestimated to be Holocene).Recurrence interval NDComments: Rupture of this segment during the 1983 earthquake is not considered primary and thusth e historic rupture is no t considered fo r determining recurrence interval. Trenching ha s documentedonly one older surface rupture.Slip rateunknown; probably < 1 mm/yrComments: No published slip rate is known, but based on maximum 5.7-m-high scarps on latestPleistocene (


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Segment number 601CS e g m e n t n a m e Thousand S pr ings segmentComm ents: Defined and named by Scott and others (1985). Extends from Wil low Creek hills southeastto Elkhorn Creek.Reliabil ity o f locat ion GoodComm ents: Location of scarps based on 1:24,000-scale maps o f Crone and others (1985; 1987).Sense o f mo v emen t NSCom ments: Crone and others (1987) report about 17% o f slip component was sinistral at th e surface,which agrees with smal l component of sinistral sl ip inferred from faul t plane solut ion (Doser and Smith,1985).DipComments :Dip direction SWGeomorph ic express ion Continuou s histor ic fault scarps having discontinuous but prominent free facealong southwest f ront of Lost River Range. Locally, faulting is expressed in numerous subparal le lscarps across a 140-m-wide zone.A ge o f faul ted deposi ts Holocene and older alluvium, locally bedrock.Detailed studies

Four trenches and another excavation, which did no t cross th e fault, have been excava ted on theThousand Spr ings segment. No datable m aterial was recovered at any of these sites. One and insome cases tw o prehistorical events were recognized. Many of the prehistorical structures werereactivated in 1983 in terms of style and amoun t of displacement (Crone, 1985; Schwartz and Crone,1985). These studies concen trated on th e West Spring, Doublespr ing Pass road, and Rock Creekareas.West Spring. Trench 601C-1 about 0.8 km northwest o f West Spr ing was excavated by Cochran in1984? (1985).Doublespr ing Pass road. The ear l iest trench (601C-2) on this segment was excavated by Hait in 1976and predates th e 1983 Borah Peak earthquake. This site (601C-3) was re-excavated by Schwartz andCrone in 1984 fol lowing the earthquake. Both trenches, which are documented in Crone (1985), wereabou t 65 m northwest of Dou blespr ing Pass road, which is north of th e middle of the segment. Anothertrench excavated in 1984 by Schwartz and Crone is 0.5 km southeast of Doublespr ing Pass road(601C-4) (Crone, 1985; Schwartz and Crone, 1985). Although it was not logged, stratigraphic relationssuggest tw o prehistorical events (Crone, oral comm., 1993).Rock Creek. Excavation 601C-5, abou t 250 m northwest of Rock Creek access road, by Cochran in1984? did no t cross the fault bu t contained Mazama ash (about 6,700 yr), which provides a max imumlimit ing age because of its position in colluvial section (Cochran, 1985). Three faul t ing events,including 1983, are inferred since 40 ka , but results are preliminary and 40-ka l imiting age is notsubstantiated by numerical dat ing methods.

Timing o f most recent paleoevent(2 ) Holocene and post glacial (


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Bucknam, personal communicat ion cited in Scott and others (1985), Hanks and Schwartz (1987),Salyards (1985), and Vincent (1985). Scarps at th e northern en d o f segment that were no t offsethistorically, th e 1983 Gap in Crone and others (1985; 1987), are older than Holocene but are probablyyounger than late Quaternary (


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Segment num ber 601DS e g m e n t n a m e Mackay segmentCom ments: Defined and named by Scott and others (1985). Extends from Elkhorn southeast to nearLower Cedar Creek.Reliabil ity o f locat ion GoodCom ments: Location of scarps based on 1:24,000-scale maps of Crone (unpu bl ished data).Sense o f m ov e m e n t NComm ents: (Scott and others, 1985)DipComments :D ip direction SWGeom orphic expression Generally continuous, morphological ly young faul t scarps on al luvium along

entire length o f segment (Crone and Haller, 1991).A g e o f faul ted deposi ts Holocene to middle Pleistocene fa n alluvium (Scott, 1982).Detailed studiesThree trenches at two sites about 16 km apart have been excavated on th e Mackay segment. Trench601D-1 (Schwartz and Crone, 1988) north of Lower Cedar Creek, near north end of segment, on pre-15-ka fan. Trench 60 1 D-2 (Hart and Scott, 1978; Scott and others, 1985) and Trench 601D-3 (Schwartzand Crone, 1988), north of Lone Cedar Creek, near south en d of segment, on pre-15-ka fan.Timing o f most recent paleoevent(2 ) Holocene and po st glacial (< 15 ka )Comments : Collectively, trenching data indicate one faul t ing event has occurred in past 1 1 k.y., timing

o f which w as between 4 and 6.8 ka . Faulted Mazama ash (approximately 6,800 yr) found in trenches atboth ends o f segment (Crone and Haller, 1991). Radiocarbon ag e of organic m atter bur ied by scarp-der ived col luvium in Trench 60 1 D-2 suggests that th e most recent event occurred abou t 4 ka (Scott andothers, 1985). Trench 60 1 D-3 contained Glacier Peak ash (11,300 yr), which is displaced by only oneevent (Schwartz and Crone, 1988).Recurrence interval NDComments :Slip rate(C ) < 1 mm/yrComments: 0.35 0.1 mm/yr (P.L.K. Knuepfer, wr it ten com m., 1992) fo r unspecif ied t ime interval.Scott and others (1985) do not provide values fo r slip rate on Mackay segment (601B), they indicate

that long-term rate may be lower than that fo r Thousand S pr ings segment (601 C) . However, latestQuaternary slip rate is probably slightly higher.Length (km) Determined fromG IS dataAverage s t r ike (azimuth) Determined from GIS dataEnd points (lat. - long.) Determined from GIS data

22


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Segment num ber 601ES e g m e n t n a m e Pass Creek segmentComments : Defined and named by Scott and others (1985). Extends f rom near Lower Cedar Creeksoutheast to approximately 3 km north o f King Canyon.Reliability o f location PoorComments: Location o f fault based on 1:24,000-scale maps o f Crone (unpub l ished data). Segm enthas fe w scarps, inferred location o f fault is at b edrock-al luvial contact.Sense o f m ov e m e n t NComments: (Scott and others, 1985)D ipComments :Dip direction SWG e o m o r p h i c expression Scarps on Quaternary deposi ts are gen eral ly absent, but most deposi ts alongrange front are though t to be young er than 15 ka (Scott and o thers, 1985; Crone and Haller, 1991).Range-front morphology is simi lar to that along adjacent segm ents, including a steep faceted front andhigh structural relief. Segment spans a major embayment in range f ront at Elbow Canyon.A ge of faulted depositsDetailed studiesTiming o f most recent paleoevent(3 ) late Quaternary (


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Segment number 601FSegment name Arco segmentComments: Defined and named by Scott and others (1985). Extends from approximately 3 km northof King Canyon to southern en d of Lost River Range. Also referred to as the Arco fault by Kuntz andothers (1984).Reliability of location GoodComments: Location of scarps based on 1:24,000-scale maps of Crone (unpublished data).Sense o f m ov e m e n t NComments: (Scott and others, 1985)DipComments :Dip direction SWGeomorphic expression Segment is generally charac terized by high scarps along much of range front.Scarps range from 2 to 25 m in height (Pierce, 1985) but most are about 12 m (Malde, 1985; 1987).High scarps are on deposits thought to be less than 600 ka, whereas 2- to 3-m-high scarps are on 30-ka deposits (Pierce, 1985). Deposits thou ght to be about 15 ka are unfaulted (Pierce, 1985; Scott andothers, 1985).A ge of faulted deposits Undtfferentiated Ho locene an d upper and middle Pleistocene alluvium andcolluvium (Scott, 1982). Scarps along southern part of segment are on 30 ka and olde r deposits; alongnorthern part of segment, scarps are on bedrock (Malde, 1985).Detailed studiesOne trench was excavated on the Arco segment. Trench 601F-1 (Malde, 1985; 1987) located on southside of unnamed stream a pproximately 6.5 km south of northern segment, boundary The 8- to 11-m-

deep trench crosses a 15-m-high scarp that ha s evidence of at least 2 faulting events. The oldest eventresulted in 4.6-6 m of displacement and the younger event resulted in at least 3 m of displacement.Timing o f most recent paleoevent(3 ) late Quaternary (


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E n d p o i n t s (lat. - long.) Determined from G IS data

25


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Section n u m b e r 60 1 gSect ion name Wil low Creek hil ls stran dComments: Refers to discontinuous scarps in Willow Creek hills that formed dur ing 1983 Borah Peakearthquake. They extend from the range-front part o f Lost River fault (near Arentson Gulch) northwestover crest of Wil low Creek hills (to near Sheep Creek). Also referred to as the W illow Summit segment

in Montana Bureau of Mines and Geo logy digital database (St ickney and B artholomew , writ tencommun. 1992).Reliabil ity o f locat ion GoodComments : Location o f scarps based on 1:24,000-scale maps of Crone and others (1985; 1987).Sense o f m ov e m e n t NSComm ents: Al though predom inantly normal with small sinistral component, localized dextral andreverse movement were also noted (Crone and others, 1987).DipComments :Dip direction SWG e o m o r p h i c expression Surface ruptures from Borah Peak earthquake are super imposed on olderscarps of unknown age along much of the Wil low Creek hills strand. The complex and discontinuous1983 surface ruptures that characterize the W illow Creek hil ls strand (601 g) are a surficialrepresentation of the com plexity of the fault at depth. The concentrat ion and d istribut ion of aftershocks,as wel l as inconsistent foca l mechanisms, suggest that s lip was a ccommod ated on a complex networko f faults near a bedrock asperity (Crone and others, 1987).A ge of faulted depositsDetailed studiesTiming of most recent paleoeventRecurrence interval NDComments :Slip rateunknown; probably


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REFERENCESBaldwin, E.M., 1951, Faulting in th e Lost River Range area of Idaho: American Journal o f Science, v.249, p. 884-902.Cochran, B.D., 1985, Age o f late Qu aternary surface ruptures along th e Thousand Springs-Mackaysegment o f th e Lost River Range faul t system, in Jacobson, M.L., and Rodriguez, T.R., compilers,National Earthquake Hazards Reduction Program, Summar ies o f technical reports, Volume XXI:U.S. Geological Su rvey Open-File Report 86-31, p. 113-121.Crone, A.J., 1985, Faul t scarps, landsl ides and other features associated with th e Borah Peak earthquakeo f October 28, 1983, central Idaho Afield trip guide, with a section on th e Doublespr ing Passroad trench by Hart, M.M., Jr.: U.S. Geological Survey Op en-File Report 85-290, volume B, 23 p.,3 pis., scale 1:24,000.Crone, A.J., and Haller, K.M., 1991, Segmentat ion and th e coseismic behavior o f Basin and Rangenormal faults Examples from east-central Idaho and southwestern Montana, in Hancock, P.L.,Yeats, R.S., and Sanderson, D.J., eds., Character istics o f act ive faults: Journal o f Structural

Geology, v. 13, p. 151-164.Crone, A.J., Machette, M.N., Bonil la, M.G., Lienkaemper, J.J., Pierce, K.L., Scott, W.E., and Bucknam,R.C., 1985, Characteristics of surface faulting accompanying th e Borah Peak earthquake, centralIdaho, in Stein, R.S., and Bucknam, R.C., eds., Proceedings o f workshop XXVIII on th e BorahPeak, Idaho, earthquake: U.S. Geological Su rvey Open-File Report 85-290, v. A, p. 43-58.Crone, A.J., Machette, M.N., Bonil la, M.G., Lienkaemper, J.J., Pierce, K.L., Scott, W.E., and Bucknam,R.C., 1987, Su rface faul t ing accompanying th e Borah Peak earthquake and segmentat ion of theLost River fault, central Idaho: Bulletin of th e Seismological S ociety of America, v. 77, p. 739-770.Doser, D.I., and Smith, R.B., 1985, Source parameters of th e 28 October 1983 Borah Peak, Idaho,

earthquake f rom body wave analysis: Bu lletin of th e Seismological Society of America, v. 75 , p.1041-1051.Hait, M.H., Jr., and Scott, W.E., 1978, Holocene faul t ing, Lost River Range, Idaho: Geological Society o fAmerica Ab stracts with Programs, v. 10, p. 217.Hanks, T.C., and Schwartz, D.P., 1987, Morphologic da t ing o f th e pre-1983 fault scarp on th e Lost Riverfaul t at Dou blespr ing Pass Road, Custer County, Idaho: Bulletin of the Seismological Society o fAmerica, v. 77, p. 837-846.Kuntz, M.A., Skipp, B. , Scott, W.E., and Page, W.R., compilers, 1984, Preliminary geologic m ap of theIdaho National Engineering Laboratory and adjoining areas, Idaho: U.S. Geological SurveyOpen-File Report 84-281, 23 p., 1 pi., scale 1:100,000.Malde, H.E., 1985, Qu aternary faul t ing near Arco and Howe, Idaho, in Stein, R.S., and Bucknam, R.C.,eds., Proceedings of workshop XXVII I on th e Borah Peak, Idaho, earthquake: U.S. GeologicalSurvey Open-File Report 85-290, v. A, p. 207-235.Malde, H.E., 1987, Qu aternary faul t ing near Arco and Howe, Idaho: Bulletin of th e Seismological Societyof America, v. 77 , p. 847-867.Pierce, K.L., 1985, Qu aternary history of faul t ing on the Arco segment o f th e Lost River fault, ce ntralIdaho, in Stein, R.S., and Bucknam, R.C., eds., Proceedings of workshop XXVIII on th e BorahPeak, Idaho, earthquake: U.S. Geological Survey O pen-File Report 85-290, v. A, p. 195-206.

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Salyards, S.L., 1985, Patterns of offset associated with th e 1983 Borah Peak, Idaho, earthquake andprevious events, in Stein, R.S., and Bucknam, B.C., eds., Proceedings of workshop XXVIII on th eBorah Peak, Idaho, earthquake: U.S. Geological Survey Open-File Report 85-290, v. A, p. 59-75.Schwartz, D.P., and Crone, A.J., 1985, The 1983 Borah Peak earthquake A cal ibration even t fo rquantifying ea rthquake recurrence and faul t behavior on Great Basin normal faul ts, in Stein, R.S.,and Bucknam, B.C., eds., Proceedings of workshop XXVIII on th e Borah Peak, Idaho,earthquake: U.S. Geological Survey Open-File Report 85-290, v. A, p. 153-160.Schwartz, D.P., and Crone, A.J., 1988, Paleoseismicity of th e Lost River fault zone, Idaho Earthquakerecurrence and segm entat ion: Geological Society o f America Abs tracts with Programs, v. 20, no .3, p. 228.Scott, W.E., 1982, Surficial geologic m ap of th e eastern Snake River Plain and adjacent areas, 111 to115 W., Idaho and Wyoming: U.S. Geological Su rvey Miscel laneou s Invest igat ions S er ies Map1-1372, 2 sheets, scale 1:250,000.Scott, W.E., Pierce, K.L., and Hart, M.H., Jr., 1985, Quaternary tectonic setting of the 1983 Borah Peakearthquake, central Idaho: Bulletin of th e Seismological Society of America, v. 75 , p. 1053-1066.Skipp, B., and Hait, M.H., Jr., 1977, Allochthons along th e northeast margin o f th e Snake River Plain,Idaho, in Heisey, E.L., Norwood, E.R., Wach, P.M., and Hale, L.A., eds., Rocky Mou ntain thrustbel t geology and resources: Wyo ming Geological Associat ion, 29th Annu al Field Conference,Teton Vil lage, Wyoming, Gu idebook, p. 499-515.Stickney, M.C., and Bartholomew, M.J., 1987, Seismicity and late Q uaternary faul t ing o f th e northernBasin and Range province, Montana and Idaho: Bulletin o f th e Seismological Society of America,v. 77 , p. 1602-1625.Stickney, M.C., and Bartholomew, M.J., written commun. 1992, Preliminary m ap of late Quaternary faultsin western Mo ntana (digital data): Montana Bureau o f Mines and Geology (digital unpubl ishedversion of MBMG Open-File Report 186), 1 pi., scale 1:500,000.Vincent, K.R., 1985, Measurement o f vertical tectonic offset using longitudinal profiles of faultedgeom orphic surfaces near Borah Peak, Idaho A preliminary report, in Stein, R.S., and Bucknam,R.C., eds., Proceedings of workshop XXVIII on th e Borah Peak, Idaho, earthquake: U.S.Geological Survey Open-File Report 85-290, v. A, p. 76-96.Witkind, I.J., 1975, Preliminary m ap showing known and suspected act ive faults in Idaho: U.S.Geological Survey Open-File Report 75-278, 7 1 p. pamphlet, 1 sheet, scale 1:500,000.

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Com pilation form fo r sectioned faultsSTRUCTURE ATTRIBUTES

Struc ture numberComments:Struc ture nam eComments:

Synops is :Date of co mp i la t ionCompi ler and aff il iationStateCounty1x2sheetProvinceGeologic sett ingN u m b e r of sect ions

Comments:Length (km) Determined fromGIS dataAverage strike (azimuth) Determined fromG IS dataEndpoin ts (lat. - long.) Determined from GIS data

SECTION ATTRIBUTESSect ion numberSect ion n a m e

Comments:Reliabil ity o f locat ion (Good, Poor)

Comments :Sense o f m o v e m e n t T R D S N

Comments :Dip

Comments :D ip direct ionG e o m o r p h i c expressionA ge o f faul ted deposi tsDetai led studiesTiming o f m o s t recen t pa leoevent CHOOSE ONE(2 ) Holocene and post glacial (


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COMPILATION FORM FO R SECTIONED FAULTS

Comments:Recurrence interval

Comments :Slip rate(A ) > 5 mm/yr

(B ) 5-1 mm/yr(C ) < 1 mm/yrunknown; probablyComments :

Length (km) Determined fromG IS dataAverage strike (azimuth) Determined f rom GiS dataEndpoin ts (lat. - long.) Determined from GIS data

REFERENCES

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Example of data fo r sect ioned faultSECTIONED FAULT ATTRIBUTES

Struc ture num ber 603Comments: Refers to number 112 ("unnamed fau l t") in Wrtkind (1975).

Structure n a m e Beaverhead faul tComments : Although Beaverhead fault was mapped and discussed by numerous authors, Skipp(1985) may be one of th e earliest to name this structure. Faul t extends from east o f town o f Tendoy,Idaho (north), where range f ront steps to east, to north margin of Snake River Plain (south).Synops is Detai led mapping of th e southern part of the faul t and reconnaissance studies of scarpmorphology are th e sole source of data fo r this faul t ; segmen tat ion model has been proposed based onthese data. No detailed site studies, such as trenching, have been conducted.Date of com pi lat ion 1 1 /12/92Compi ler and aff il iation Kathleen M. Haller, U.S. Geological SurveyState IdahoCounty Lemhi; Clark1x2sheetDuboisProv ince Northern Rocky MountainsGeologic sett ing High-angle, down-to-southwest, range-front normal faul t bounding west side ofBeaverhead Mountains.N u m b e r o f sect ions 6

Comments : Hal ler (1988) defined 6 segments o f Beaverhead faul t , but because of reconnaissancenature o f study, Halter's segments are considered here as sect ions.Length (km) Determined fromG S dataAverage strike (azimuth) Determined fromG S dataEndpoin ts (lat. - long.) Determined from GiS data

3 1


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EXAMPLE OF DATA FO R SECTIONED FAULT

SECTION ATTRIBUTESSect ion number 603aSect ion n a m e Lemhi section

Comments: Defined as Lemhi segment by Haller (1988). Extends from northern en d o f fault east o fTendoy, Idaho, to north of Peterson Creek (south).Reliabil ity o f locat ion GoodComments: Location of scarps based on 1:250,000-scale maps of Ha l ler (1988), original mapping at1:24,000 o r 1:62,500 scale.

Sense o f m o v e m e n t NComments :

D ipComments :

D ip direct ion S WG e o m o r p h i c expression This sect ion o f fault characterized by discontinuous poor ly preserved scarps(Haller, 1988).A ge o f faul ted deposi tsDetai led studiesTiming o f m o s t recen t pa leoevent(4 ) middle and late Quaternary (


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E X A M P LE O F DATA FO R SECTIONED FAULT

Sect ion number 603bSect ion name Mollie Gulch section

Comments: Defined as Mollie Gulch segment by Hal ler (1988). Extends from north of Peterson Creek(north) to west o f Jakes Canyon (south).Reliability o f location Good

Com ments: Location of scarps based on 1:250,000-scale maps of Hal ler (1988), or iginal m apping at1:24,000 or 1:62,500 scale.Sense o f m ov e m e n t N

Comments :Dip

Comments:Dip direction SWGeomorphic expression Scarps are general ly poor ly defined and high on m ountain front, no scarps onalluvium (Haller, 1988; Crone and Haller, 1991).A ge o f faulted depositsDetailed studiesTiming o f most recent paleoevent(2 ) Holocene and post glacial (


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Sect ion number 603cSect ion name Leadore section

Comm ents: Defined as Leadore segm ent by Hal ler (1988). Extends from west of Jakes Canyon (north)to near Eighteenmile Creek (south) . Includes Canyon Creek and Hawley Creek segments in MontanaBureau o f Mines and Geology digital database (St ickney and Bartholomew, writ ten commun. 1992) andHawley Creek scarp o f Stickney and Bartholomew (1987).Reliability o f location GoodComments: Location of scarps based on 1:250,000-scale maps o f Hal ler (1988), or iginal ma pping at1:24,000 or 1:62,500 scale.

Sense o f m ov e m e n t NComments :

DipComments :

Dip direction SWG e o m o r p h i c expression Section spans major embayment in range f ront and is character ized bygeneral ly continuous morphological ly young scarps on al luvium. Grabens are well preserved and asmuch as 0.3 km wide (Haller, 1988; Crone and Haller, 1991).A ge o f faul ted deposi ts Scarps are formed on all but late Holocene al luvial deposits.Detai led s tud iesTiming o f most recent paleoevent(2 ) Holocene and post glacial (


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Sect ion number 603dSect ion n a m e Baldy Moun tain sect ion

Comments: Defined as Baldy Mountain segment by Hal ler (1988). Extends from near EighteenmileCreek (north) to west of Eighteenmile Peak, near Gi lmore S umm it (south). Includes Dry Canyonsegment in th e Montana Bureau of Mines and Geology digital database (St ickney and Bartholomew,writ ten commun. 1992).Reliability o f location PoorComments : Inferred location o f fault at bedrock-al luvial contact, source of trace based on 1:250,000-scale maps of Hal ler (1988), or iginal m apping at 1:24,000 o r 1:62,500 scale.

Sense o f m ov e m e n t NComments :

D ip 80 S WComments : Faul t exposed on north side of Chamberlain Creek in approximately 14-m-deep stream cu t(Haller, 198 8). Dip cited is apparent dip of b edrock-al luvial contact.

D ip direction SWGeomorph ic expression Faul t defined by al igned springs and discontinuous scarps on bedrock. Scarpson Quaternary deposi ts are general ly absent, but most deposi ts along range f ront are thought to beyounger than about 25 ka (Haller, 1988). Range-front morphology is similar to that along adjacentsections including a steep faceted profile, high structural relief, and unembayed mountain front.A ge o f faulted depositsDetailed studiesTiming o f m os t recent paleoevent(3 ) late Quaternary (


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Section n u mber 603eSect ion name Nicholia section

Comments: Defined as Nicholia segment by Hal ler (1988). Northern end of sect ion is near GilmoreSummit, and scarps are absent along northern 8 km. Scarps extend from near Mud Creek (north) toTimber Canyon (south) . Includes No rth Nicholia, Nicholia, South Nicholia, and Scott Canyon segmentsin Montana Bureau of Mines and Geology digital databa se (St ickney and Bartholomew, writtencommun. 1992) and N ichol ia scarp of Stickney and Bartholomew (1987).

Reliability o f location GoodComments: Location of scarps based on 1:250,000-scale maps of Haller (1988), original mapping at1:24,000 or 1:62,500 scale.

Sense o f mo v emen t NDComments: (Scott and others, 1985)

D ipComments:

D ip direction SWG e o m o r p h i c expression Section spans major embayment in range front. Nearly continuous, prominentscarps characterize southern 34 km (Haller, 1988; Crone and Haller, 1991).A g e o f faul ted deposi ts Upp er Pleistocene (-15 ka ) glacial outwash, and upper Pleistocene andundifferentiated Pleistocene al luvium (Scott, 1982).Detailed studiesTiming of most recent paleoevent(2 ) Holocene and post glacial (


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Section num ber 603fSect ion name Blue Dome section

Comments: Defined as Blue Dome segment by Haller (1988). Extends from near the town of LonePine, Idaho (north), to southern end of th e fault at north margin of Snake River Plain. Rodgers andAnders (1990) refer to this section a s Blue Dome segment of Birch Creek fault.Reliability of location Poor

Comments: Inferred location of fault at bedrock-alluvial contact, source of trace based on 1:250,000-scale maps of Haller (1988), original mapping at 1:24,000 or 1:62,500 scale.Sense of m ov e m e n t N

Comments:Dip

Comments:Dip direction SWGeomorphic expression Fault extends along southernmost part of range at bedrock-alluvium contact.

Topographic relief is low and scarps on alluvium rare. Locally, Paleozoic limestone is present at th esurface on both sides of fault (Crone and Haller, 1991).Age of faulted depositsDetailed studiesTiming of most recent paleoevent(5 ) Quaternary (


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REFERENCESCrone, A.J., and Haller, K.M., 1991, Segmentat ion and the coseismic behavior of Basin and Rangenormal faults Examples from east-central Idaho and southwestern Montana, in Hancock, P.L.,Yeats, R.S., and Sanderson, D.J., eds., Characteristics of act ive faul ts: Journal o f StructuralGeology, v. 13 , p. 151-164.Haller, K.M., 1988, Segmentat ion o f th e Lemhi and Beaverhead faults, east-central Idaho, and Re d Rockfaul t , southwest Montana, dur ing th e late Quaternary: Boulder, University of Colorado,unpubl ished M.S. thesis, 141 p., 10 pis.Rodgers, D.W., and Anders, M.H., 1990, Neogene evolut ion of Birch Creek Valley near Lone Pine, Idaho,in Roberts, S., Geologic f ield tours of western Wyoming and parts o f adjacent Idaho, Montana,and Utah: Geological Survey o f Wyoming Public Information Circular 29 , p. 27-38.Scott, W.E., 1982, Surficial geologic map of th e eastern Snake River Plain and adjacent areas, 111 to115 W., Idaho and Wyoming: U.S. Geological Su rvey Miscel laneous Invest igat ions Ser iesMap 1-1372, 2 sheets, scale 1:250,000.Scott, W.E., Pierce, K.L., and Hart, M.H., Jr., 1985, Quaternary tectonic sett ing of th e 1983 Borah Peakearthquake, central Idaho: Bulletin of th e Seismo logical Society of America, v. 75 , p. 1053-

1066.Skipp, B., 1985, Contract ion an d extension faults in the southern Beaverhead Mountains, Idaho andMontana: U.S. Geological Survey O pen-File Report 85-545,170 p.Stickney, M.C., and Bartholomew, M.J., 1987, Seismicrty and late Quaternary faulting of the northernBasin and Range province, Montana and Idaho: Bulletin o f th e Seismological Society ofAmerica, v. 77, p. 1602-1625.Stickney, M.C., and Bartholomew, M.J., written commun. 1992, Preliminary m ap o f late Quaternary faultsin western Montana (digital data): Montana Bureau o f Mines and Geology (digital unpubl ishedversion o f MBMG Open-File Report 186), 1 pi., scale 1:500,000.Witkind, I.J., 1975, Preliminary map showing known and suspected active faults in Idaho: U.S.Geological Survey Open-File Report 75-278, 7 1 p. pamphlet, 1 sheet, scale 1:500,000.

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Compilation form fo r simple faultsSTRUCTURE ATTRIBUTES

Struc ture numberComments:Structure n a m eComments:

Synops is :Date o f compi la t ionC o m p i l e r and aff il iationStateC o u n t y1x2sheetProvinceReliabil ity o f locat ion (Good, Poor)

Comments :Geologic sett ingSense o f m o v e m e n t T R D S N

Comments :Dip

Comments :D ip direct ionGeomorph ic expressionA g e o f faul ted deposi tsDetai led studiesTiming o f most recen t pa leoevent CHOOSE ONE:(2 ) Holocene and po st glacial (< 15 ka )(3) late Quaternary (


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COMPILATION FORM FO R SIMPLE FAULTS

End points (lat. - long.) Determined from GIS dataR E F E R E N C E S

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Example of data fo r simple faul tSIMPLE FAULT ATTRIBUTES

Structure num ber 605Comments: Refers to number 226 ("unnamed fau l t") in Wrtkind (1975).Struc ture name Unnamed faultComments : Main branch of faul t extends from Deadwood Summit (north) to f lank of Wi ld Buck Peak(south). Eastern branch extends across irregular topography from headwaters of Sulphur Creek (north)to near Deadwood Lodge (south) where it intersects with main branch.

Synops is Fault is poor ly understood, no known work has been completed at t ime of com pilation.Date o f compi la t ion 12/1 7/92Compi ler and aff il iation Kathleen M. Haller, U.S. Geological SurveyState IdahoC o u n t y Valley1x 2 sheet ChallisProv ince Northern Rocky MountainsReliabil ity o f locat ion Poor

Com ments: Location of faul t based on 1:500,000-scale m ap o f Witkind (1975).Geologic sett ing High-angle, down-to-southeast, normal faults along west side of Deadman River andeast side of East Fork Deadman River. Sense of movement on eastern branch general ly opposes localtopography.Sense o f m ov e m e n t N

Comments: (Witkind, 1975)D ip

Comments:Dip direction SEGeomorphic expressionA ge o f faul ted deposi ts Pleistocene mo raines (Schmidt and Mackin, 1970).Detai led studiesTiming o f most recent paleoevent(3 ) late Quaternary (


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EXAMPLE OF DATA FOR SIMPLE FAULT

REFERENCESSchmidt, D.L., and Mackin, J.H., 1970, Quaternary geology of Long and Bear Val leys, west-central Idaho:U.S. Geological S urvey Bu l let in 1311-A, 22 p., 2 pis.Witkind, I.J., 1975, Preliminary m ap showing known and suspected act ive faults in Idaho: U.S.Geological Survey Open-File Report 75-278, 7 1 p. pamphlet, 1 sheet, scale 1:500,000.

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Compi la t ion form for historical surface faultingH I S T O R I C A L SURFACE F A U L T I N G

Name o f earthquakeComments :Affected st ructures) , segment(s) , o r sect ion numbers

DateMagn itude or intensi ty

Comments:Mom ent magni tude or se ismic m oment

Comments:Location o f epicenter

Comments:Depth o f epicenterComments:Sense o f m ov e m e n t T R D S N

Comments:D ip

Comments:Maximum sl ip at surface

Comments:Geophysical average slip

Comments :Length o f surface rupture Determined from GIS data

Comments :R E F E R E N C E S

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Example of data for historical surface fault ing earthqua keH I S T O R I C A L SURFACE F A U L T I N G

N a m e o f earthquake Borah Peak earthquakeComments:Affected structures), segment (s ) , o r sec t ion numbers 601C; 601B; 60 1 g; 604bDate 10/28/1983Magnitude o r intensity M s = 7.3Comments: (Dewey, 1987)M o m e n t m a g n i tu d e o r s e is m i c m o m e n t M0 = 2.9 x 10 2 6 dyne-cmCom ments: Seismically derived mom ent is less than that derived geodetically (M 0 = 3.2 x 102 6dyne-cm) by Stein an d Barrientos (1984). Sum o f scalar moments was 2.86 x 10 2 6 dyne-cm,but 3.5 weeks of aftershocks contributed to only 6% to the total seismic moment (Smith andothers, 1985).Locat ion of ep icenter 43.974 N; 113.916 WComments: (Dewey, 1987). Epicenter was about 15 km south-southwest of termination of

recognized surface faulting(Doser and Smith, 1985). Rupture propagated up and unilaterally tonorthwest, contrary to eyewitness report in Wallace (1984).Depth of ep icenter 14-16 kmComments: Dewey(1985; 1987) reported 14 km, whereas 15-16 km was reported by Doserand Smith (1985).S e n s e o f m o v e m e n t N SComments: Crone an d others (1987) report about 17 % of slip component was sinistral at thesurface, which agrees with small component of sinistral slip inferred from fault plane solution(Doser and Smith, 1985).D ip 45-62S WComments: Subsurface dip of fault from variety of sources; se e Richins an d others (1987) fo rdetails.M a x i m u m s li p at surface 2.7 mComments: Maximum is net vertical throw; average vertical throw along entire rupture 0.8 m;average vertical throw along Thousand S prings segment (601 C) 1.1m, 58% of length of ruptureon Thousand S prings segment ha d scarps that exceeded 1 m in throw; left-lateral componentwas approximately 17% of vertical (Crone and others, 1985; 1987). Some individual scarps arenearly 5 m high (Crone and Haller, 1991), but were associated with grabens and localbacktilting.Geophys ica l average slip 1.4-2.1 mComments: Preferred m odel fo r geode tic data (Barrientos and others, 1987) indicates 2 . 1 m ofslip at southern en d of rupture and 1.4 m of slip at the no rthern end of rupture on a single planarfault dipping 49 SW with dimensions of 26 km long by 18 km (south end) to 8 km (north end)wide. Calculations based on the seismic mom ent suggest 1.4 m of slip (Doser and Sm ith,1985).Length o f sur face rupture Determined from GIS dataComments: 36.4 3.1 km reported by Crone and others (1987); length is not su m of tracelengths of various parts of rupture but is a straight-line length. They believe that the 20.8-km-long rupture on Thousand Springs segment (601 C) represents the prima ry rupture and the 7.9-km-long rupture on Warm S pring segment (601 B) and 14.2 km on the nearby Willow Creek hillsstrand (601 g) and Lone Pine fault (604b) are a secondary result of triggered slip. Geod etic data(Barrientos an d others, 1987) support this interpretation.

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E X A M P LE O F DATA FO R HISTORICAL SURFACE FAULTING E A R T HQU A K E

R E F E R E N C E SBarrientos, S.E., Stein, R.S., and Ward, S.N., 1987, Compar ison of the 1959 Hebgen Lake,Montana and th e 1983 Borah Peak, Idaho, earthquakes f rom geo detic observations:Bulletin of th e Seismological Society o f America, v. 77, p. 784-808.Crone, A.J., and Haller, K.M., 1991, Segmentat ion and th e coseismic behavior of Basin andRange normal faults Examples from east-central Idaho and southwestern Montana, inHancock, P.L., Yeats, R.S., and Sanderson, D.J., eds., Characteristics o f active faults:Journal o f Structural Geology, v. 13, p. 151-164.Crone, A.J., Machette, M.N., Bonil la, M.G., Lienkaemper, J.J., Pierce, K.L., Scott, W.E., andBucknam, R.C., 1985, Character istics of surface faulting accompanying th e Borah Peakearthquake, central Idaho, in Stein, R.S., and Bucknam, R.C., eds., Proceedings ofworkshop XXVIII on th e Borah Peak, Idaho, earthquake: U.S. Geological SurveyOpen-File Report 85-290, v. A, p. 43-58.Crone, A.J., Machette, M.N., Bonil la, M.G., Lienkaemper, J.J., Pierce, K.L., Scott, W.E., andBucknam, R.C., 1987, Surface faul t ing accompanying th e Borah Peak earthquake andsegmentat ion of th e Lost River fault, central Idaho: Bulletin of th e SeismologicalSociety of America, v. 77, p. 739-770.Dewey, J.W., 1985, Instrumental seismicity of central Idaho, in Stein, R.S., and Bucknam, R.C.,eds., Proceedings of workshop XXVIII on th e Borah Peak, Idaho, earthquake: U.S.Geological Survey Open-File Report 85-290, v. A, p. 264-284.Dewey, J.W., 1987, Instrumental seismicity of central Idaho: Bulletin of th e Seismological Societyo f America, v. 77, p. 819-836.Doser, D.I., and Smith, R.B., 1985, Source pa rameters o f th e 28 October 1983 Borah Peak,Idaho, earthquake from body wave analysis: Bulletin o f th e Seismological Society ofAmerica, v. 75 , p. 1041-1051.Richins, W.D., Pechmann, J.C., Smith, R.B., Langer, C.J., Goter, S.K., Zol lweg, J.E., and King,J.J., 1987, The 1983 Borah Peak, Idaho, earthquake and its aftershocks: Bulletin of th eSeismological Society of America, v. 77 , p. 694-723.Smith, R.B., Richins, W.D., and Doser, D.I., 1985, The 1983 Borah Peak, Idaho, earthquake-Regional seismicity, kinematics of faulting, and tectonic mechanism, in Stein, R.S., andBucknam, R.C., eds., Proceedings of workshop XXVIII on th e Borah Peak, Idaho,earthquake: U.S. Geological Su rvey Open-File Report 85-290, v. A, p. 236-236.Wal lace, R.E., 1984, Eyewitness account of surface faulting during th e earthquake of 28 October1983, Borah Peak, Idaho: Bulletin of th e Seismological Society of America, v. 74 , p.1091-1094.

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