Late Quaternary activity along the Lone Pine fault, eastern California

LESTER K.C. LUBETKIN U.S. Forest Service, Eldorado National Forest, Placerville, California 95667 MALCOLM M. CLARK U.S. Geological Survey, Menlo Park, California 94025

ABSTRACT

The Lone Pine fault is a north-trending secondary break of the Owens Valley fault zone, 1.4 km west of Lone Pine, California. This fault forms an east-facing scarp as much as 6.5 m high across an abandoned outwash fan of the Tioga (latest Pleistocene) glaciation. The fault experienced large right-lateral and smaller vertical displace-ment during the 1872 Owens Valley earthquake. Knowledge of the character and amount of slip at this site in and before 1872 is neces-sary for evaluations of earthquake hazard near Owens Valley and may help us to understand earthquakes along other parts of the eastern front of the Sierra Nevada and in the Great Basin.

Scarp profiles indicate a 1- to 2-m component of dip slip in 1872; thus three 1872-type earthquakes could have created the scarp. This number of events is also indicated by desert-varnish patterns on boulders in the fault scarp, by scarp morphology, and by sediments near the fault. Horizontal offset of a relict channel on the fan is 12 to 18 m (3 earthquakes). Horizontal offset of a younger debris flow is 10 to 12 m (apparently 2 earthquakes).

Average horizontal offset for each earthquake, including that of 1872, is 4 to 6 m. The age of the fan surface is bracketed by a 21 ka shoreline of former Lake Owens and by the time of abandonment of the fan, about 10 ka. An average recurrence interval for 3 earthquakes is 5,000 to 10,500 yr. The average recurrence interval, combined with the average oblique offset for each event of 4.3 to 6.3 m, gives an average late Quaternary slip rate of 0.4 to 1.3 mm/yr for the Lone Pine fault. If we add the average horizontal-slip component for the Lone Pine fault to the 1872 horizontal slip reported for the adjacent main Owens Valley trace of 2.7 to 4.9 m, the combined 1872 horizon-tal-slip component for the Owens Valley fault zone is approximately between 7 and 11 m, a large value. The associated horizontal-slip rate for the Owens Valley fault zone is 0.7 to 2.2 mm/yr.

INTRODUCTION

The great earthquake of March 26, 1872, in Owens Valley was one of the three largest historic shocks in California. The earthquake was associated with extensive strike-slip and oblique-slip surface faulting along the Owens Valley fault zone in eastern California (Fig. 1) and caused strong ground shaking throughout a vast region (Oakeshott and others, 1972). Little has been published about the surface ruptures of 1872 and previous late Quaternary faulting in this region, however. Several geolo-gists made limited observations of the surface rupture during the 35 yr after the earthquake (Whitney, 1872; Gilbert, 1884; Hobbs, 1910). More recent investigations classified patterns of 1872 and earlier faulting in Owens Valley (Slemmons and Cluff, 1968; Carver and others, 1969), verified reported 1872 right slip of about 4 m (Bateman, 1961; Bonilla,1968), and analyzed 1872 and earlier normal faulting on a branch of the Owens

Geological Society of America Bulletin, v. 100, p. 7 5 5 - 7 6 6 , 1 2 figs., 2 tables, May 1988.

Figure 1. Location of Owens Valley fault zone, Lone Pine fault, and other faults that comprise the Owens Valley fault zone near Lone Pine. Ball on downthrown side of fault scarps; faults dashed where approximately located. Star identifies 14C sample site (USGS 609).

Valley fault zone south of Big Pine (Martel, 1984; Martel and others, 1987). No earlier investigations, however, have concentrated on either total 1872 displacement or horizontal displacement from earlier earth-quakes along the Owens Valley fault zone. In 1985-1986, Sarah Beanland completed a comprehensive field study of the entire 1872 rupture and the Owens Valley fault zone (Zoback and Beanland, 1986; Beanland and

755

756 LUBETKIN AND CLARK

Clark, 1987). Indeed, the prominent scarp that is the subject of our report was widely and incorrectly identified to be the result of displacement solely in 1872 (for example, Hobbs, 1910; Townley and Allen, 1939; Richter, 1958, p. 502), although its origin from at least three earthquakes was later noted by D. B. Slemmons and his students (Oakeshott and others, 1972, p. 56). Furthermore, earlier emphasis on the dip-slip compo-nent along this scarp has obscured the fact of dominant strike slip along this scarp, the 1872 rupture, and the Owens Valley fault zone. Knowl-edge of the character and amount of slip in 1872 and during earlier earthquakes is necessary for evaluation of seismic hazard near Owens Valley and also may be of value in assessing slip rates and recurrence intervals for other faults along the eastern front of the Sierra Nevada and elsewhere in the Great Basin.

This study focuses on late Quaternary activity along the Lone Pine fault, a major strand of the Owens Valley fault zone. We investigated the prominent scarp of this fault across an abandoned fan of Lone Pine Creek. This scarp and fan surface preserve some of the clearest evidence in the Owens Valley fault zone of 1872 and earlier oblique displacement. Our analysis starts with estimates of the 1872 dip-slip component of displace-ment, which we then compare to the total dip-slip component recorded by the scarp to determine that three 1872-sized earthquakes formed the scarp. We determine the larger horizontal component of offset from a channel and a debris flow that are offset at the scarp. Finally, from our estimate of

the age of the fan, we determine average earthquake recurrence intervals of 5,000 to 10,500 yr and slip rates of 0.4 to 1.3 mm/yr for this part of the Lone Pine fault, and estimate a horizontal slip rate of 0.7 to 2.2 mm/yr for the Owens Valley fault zone near Lone Pine.

The Owens Valley fault zone near the town of Lone Pine consists of a main trace and many branch and secondary traces (Fig. 1). The main fault trace, called the "Owens Valley fault" in this report, extends across the western part of Lone Pine and forms the east side of Diaz Lake to the south. Prominent secondary traces lie as much as 1.4 km west of the main trace at Lone Pine and extend discontinuously to Diaz Lake. Lubetkin (1980) informally named the most westerly of these prominent secondary faults the "Lone Pine fault."

Scarps of the Lone Pine fault across the surface of the abandoned fan of Lone Pine Creek (Fig. 2) locally reach as high as 6.5 m. The most conspicuous scarp forms the west side of a 100-m-wide graben across the lower part of the fan. Other scarps, facing both east and west, cross higher parts of the fan.

Two large former channels of Lone Pine Creek (LPC 2 and 3, Fig. 2) incise the fan and are cut by the conspicuous scarp at the west side of the graben. LPC 2 is the younger. It cuts across the head of LPC 3 and was active until abandonment of the fan. The fan surface is now inactive except for minor local runoff in the old channels, on-going encroachment of locally derived colluvium along the western and northwestern margins,

E X P L A N A T I O N I Alluvium (Holocene) - Predominantly derived

tÜÜJ from Sierra Nevada « • .1 Alluvium and colluvium (Holocene) - Derived U - i J from Alabama Hills _ _ Alluvial fan (Pleistocene) - Composed fcfol predominantly of glacial outwash from

Sierra Nevada Metavolcanic rocks (Triassic) contact, dashed where \ approximately located

terrace, dashed line at crest of channel band, hachures point downslope Abandoned channel of Lone Pine Creek

w 1)! îî?®)! : ; ; If?:1: : : :??pa i W ^

Figure 2. Geologic map showing scarp of Lone Pine fault across abandoned fan of Lone Pine Creek. LPC 2 and LPC 3 are former channels of Lone Pine Creek. Location shown on Figure 1.

Figure 3. Idealized profile of fault scarp; modified from Wallace (1977).

LATE QUATERNARY ACTIVITY, LONE PINE FAULT, CALIFORNIA 757

and infrequent debris flows derived from the hills of metamorphic rock north of LPC 2 (Fig. 2).

The channel of LPC 2 was active after at least one event of faulting. It is more deeply incised than the other relict channels and has deposited a fan in the northern part of the graben in response to faulting. This fan in the graben and the channel of LPC 2 are now partly covered with a veneer of post-abandonment metamorphic debris.

1872 COMPONENT OF DIP SLIP

For the 1872 earthquake, we estimate the dip-slip component from fan morphology, detailed profiles and weathering features along the scarp, and scarp-derived sediments exposed in a backhoe trench across the fault.

Profiles and Weathering Features of the Fault Scarp

The Lone Pine fault scarp has an upper convex portion, a steep mid-slope, and a lower concave portion (Fig. 3). The scarp is compound, the result of more than one slip event. The steep mid-slope is the erosion-ally modified scarp of the most recent slip event, whereas the upper convex

portion is the modified scarp remnant from one or more older slip events. The lower concave portion is a sedimentary apron that conceals the origi-nal fault scarp and consists of colluvium from the upper part of the scarp and wash deposits derived from the scarp and colluvium.

The fault scarp is the modified surface expression of the fault plane. The originally exposed fault surface is no longer completely preserved, hence the position and dip of the fault plane cannot be directly measured without subsurface exposures. Natural and artificial exposures of the Owens Valley fault zone in the Lone Pine area show that most fault planes dip steeply (70° to 90°) and trend approximately parallel to the scarp of the Lone Pine fault. Erosional retreat of 1 m or more is common for the youngest fault scarps.

Figure 4 shows profiles of the present ground surface at eight sites, prepared by the method of Wallace (1977). From these profiles, we recon-structed 1872 post-earthquake surface profiles from features of the present fault scarp that record, or are remnants of, the 1872 pre-earthquake scarp. These features include the upper convex slope, the wash-controlled slope, exposed desert varnish rings, caliche coatings on clasts, and weathering of cobbles and boulders. The varnish rings on boulders exposed in the scarp show the actual position of an earlier ground surface (Smith, 1979),

PROFILE 12

PROFILE 13

desert varnish ring

p r e s e n t s u r f a c e p ro f i l e

m e t e r s

PROFILE 11

boulder 1, f igure 5 -desert varnish r ing-

boulder 2, f igure 5 -

TRENCH

Lone Pine Fault

PROFILE 14

deser t varnish ring

PROFILE 15

patchy cal iche coat ing

e s t i m a t e d 1907 s u r f a c e p r o f i l e

r e c o n s t r u c t e d 1872 p o s t - e a r t h q u a k e s u r f a c e p ro f i l e

Figure 4. Present and reconstructed 1872 post-earthquake and 1907 profiles across Lone Pine fault scarp. Locations of profiles shown on Figure 6.

758 LUBETKIN AND CLARK

Figure 5. Lone Pine scarp in 1907 (left) and 1978 (right), showing changes in free face and debris and wash slopes during 71 yr. Little or no change has occurred on the upper convex slope (above A-A'). Individual cobbles and boulders (numbered) are recognizable in both photo-graphs, although camera positions were not identical. View west at profile 11, 35 m north of LPC 3 (Figs. 4, 6). Rod is 4 m long. 1907 photograph is by W. D. Johnson, no. 685; USGS Library, Denver.

whereas caliche coatings and disintegrated clasts, which develop near but below the surface (Birkeland, 1974), commonly indicate only a lower limit for the position of the earlier surface. The reconstructed 1872 profiles closely approximate the scarp just after the earthquake, before erosional or depositional modification.

Detailed comparisons between 19071 and 1978 photographs at var-ious places along the fault scarp show that the upper convex slope and the wash slope have experienced little degradation or aggradation during this period, except for incision of the upper convex slope by some narrow rills. In contrast, material eroded from the mid-slope buries the lower portion of the scarp (Fig. 5). Both these photographs and more recent field compari-sons show no more than a few centimetres of change in the upper convex slope and little change in the wash slope, surfaces that have been essen-tially stable for nearly 80 yr.

Desert-varnish rings on boulders provide evidence that the former ground surface around the boulders must have been stable for a period of time at least as great as that required for development of such coatings above the surface, probably on the order of hundreds of years (Dorn and others, 1986,1987). Projections of the planes of exposed rings toward the fault scarp are coplanar with the lower part of the upper convex slope (Fig. 4). That is, the former ground surface recorded by the rings of desert

•Photographs taken by Willard D. Johnson during a study of the effects of the 1872 earthquake. The photos are in the Denver library of the U.S. Geological Survey. Johnson's work was reported by Hobbs (1910).

varnish on boulders coincides with the portion of the scarp that has been nearly stable during the past 80 yr. This stability strongly suggests that the upper convex slope and its down-dip projection through the surface repre-sented by the varnish rings represents the actual ground-surface profile before and immediately after the most recent faulting in 1872.

The lower portion of each reconstructed profile includes the lower original fan surface, the wash slope, and a projection of the wash slope into the fault. Several 1907 photographs show only a small debris slope and an apparently older wash slope (for example, Fig. 5, left). A larger debris slope now covers part of the older wash slope. Eventually a new wash slope will result from reworking of material from the scarp and new debris slope. We project the older wash slope to our estimated position of the fault plane to help reconstruct the post-1872 earthquake profiles of Figure 4.

We estimate a dip-slip component of 1 to 2 m along this fault in 1872 (Fig. 6), by measuring slip on these reconstructed 1872 post-earthquake profiles. We assumed fault dips of both 70° and 90° in order to bracket the most likely value of dip slip. We also estimated 1872 dip slip at five other sites with very small debris slopes (63 and 70 to 73, Fig. 6) by projecting, in the field, the upper convex slope to the fault plane. We approximate the position of the 1872 fault plane from the position of exposed boulders in the mid-slope of the scarp, together with observed fault-plane dips and our estimate that post-1872 scarp retreat throughout the study area varies from 0 to 2 m.

The presence of a horizontal component of offset introduces a small

LATE QUATERNARY ACTIVITY, LONE PINE FAULT, CALIFORNIA 759

B

a J

»

a. a.

ii I

i» o

ii

i \

1 - I 1 1 1 1 r 500 1000

HORIZONTAL DISTANCE ALONG FAULT TRACE ( METERS )

i 1 r 1500

Figure 6. Variation of 1872 and total dip slip along Lone Pine fault. A. Plan view of Lone Pine fault showing locations of numbered profiles (P; Fig. 4), displacement measurement sites (numerals; Table 1), trench (T; Fig. 7), and offset debris flow (D; Fig. 11), on the abandoned fan of Lone Pine Creek. LPC 2 and LPC 3 are abandoned channels of Lone Pine Creek. See Figure 2 for location of fault. B. Estimated dip slip in 1872 (heavy lines) and cumulative dip slip since abandonment of fan (light lines) at locations shown in A, for assumed fault dips of 70° (open circles) and 90° (solid circles). Length of lines approximates uncertainty in measurements.

error into our analysis of each profile. This error depends mainly on local surface slope parallel to the scarp. Because this slope is small at all of our profiles, the resulting error is generally less than that from the measure-ments and assumptions used in reconstructing the dip-slip component at each profile.

We conclude that the most recent slip event recognizable in the reconstructed profiles is that associated with the 1872 earthquake, not an older or younger one. We base our conclusion on the reports of extensive ground rupturing, with creation of scarps, along faults of the Owens Valley fault zone in 1872, the lack of any reported post-1872 faulting, and on the extensive steep mid-slope preserved along the scarp. In the brief pre-1872 historic record, the only earthquake that might have been large enough to produce surface rupture was a "similar earthquake" "about 80 years be-fore the shocks of 1872" described by Paiute Indians (Townley and Allen, 1939, p. 21). Neither surface displacement nor any other effects have been reported for this earlier earthquake. Its existence is doubtful (Martel, 1984).

Subsurface Exposure

A backhoe trench excavated across the Lone Pine fault scarp during this study (T, Fig. 6) exposed the eroded and buried portion of the fault scarp and a small filled-in graben at the base of the scarp (Fig. 7). The trench exposure shows that the dip-slip component along this trace in 1872 was about 1.5 m, and the scarp has retreated about 0.8 m since then. The post-fan deposits east of the main trace record a series of earthquakes, explained below and in Figure 7.

EARTHQUAKES RECORDED BY THE DIP-SLIP COMPONENT

Consideration of total scarp height, dip slip in 1872, and coatings on boulders exposed in the scarp across the Lone Pine fan suggests that slip during three earthquakes created the scarp. In Figure 6, we show the scarp's total dip-slip component for assumed fault dips of 70° and 90°.

760 LUBETKIN AND CLARK

RECONSTRUCTED 1872 POST-EARTHQUAKE PROFILE

METERS 8 6 4

BOTTOM OF TRENCH

FIGURE 7 EXPLANATION

CORRELATION OF UNITS

1 Holocene

J Pleistocene

Original Fan Deposit Debris Deposit Wash Deposit

^ ^ ^ Granitic clast > 100 mm across.

Contact , dashed where location uncertain.

— ~ Fault.

Figure 7. Subsurface exposure of Lone Pine fault (location at T, Fig. 6). A. Interpretive log of backhoe trench. Derived from descriptive log in Lubetkin (1980); modified by subsequent anal-yses of photographs of the trench wall. An aggradational wedge of debris eroded from fault scarps (units A, B, C, and D) overlies original outwash fan deposit (unit F). Unit A is gravelly silt; unit B, sandy silt to pebbly sandy silt; unit C, gravelly silty sand; unit D, gravelly sand to gravelly silty sand; unit F, gravelly silty sand. Unit D, a debris deposit, contains greater fraction of 50-mm and larger clasts than units B and C to the east and may actually consist of two gravelly sand lenses that could not be discrimi-nated. Principal trace of Lone Pine fault is westernmost fault. This fault juxtaposes unit F to the west against unit D to the east. Above unit D, this fault contact changes to an erosional contact between units F and A and is the eroded and buried 1872 fault scarp. Unit A postdates 1872 faulting and is the debris deposit produced by continuing scarp erosion and retreat. Units B and C are wash deposits that developed from erosion of scarps of two pre-1872 earthquakes.

B. Postulated development of the Lone Pine fault scarp at the backhoe trench. (1) First earthquake creates a 1.8- to 2.3-m-high east-facing scarp and a graben in unit F. Existence of fault at 2.9 on horizontal scale is not certain; block west of it may have fallen from main scarp. (2) Subsequent erosion of east-facing scarp creates lens of coarse debris (unit D) at base of scarp and wash deposit (unit C) to the east, filling in graben. (3) Second earthquake creates 1.5- to 2.2-m-high scarp at base of older, eroded scarp. Additionally, the graben east of the scarp has deep-ened, offsetting unit C. (4) Subsequent erosion and retreat of this most recent portion of the scarp adds debris to unit D at the base of the scarp. Erosion has reduced the low west-facing scarp shown in drawing 3 and redeposited the material to the west, still shown as unit C for simplicity. A second wash deposit (unit B) fills the graben. 1978 profile, shown in Figure 7A, includes 1.5 m of offset from 1872. Unit A is debris that has accumulated from erosion and spalling of the 1872 fault scarp and has subsequently buried the scarp. The faults in the graben did not move in 1872, as unit B is not offset. Only a small wash deposit has developed from the 1872 earthquake. This evolutionary drawing does not include any variations caused by horizontal slip.

This total slip component was either measured from the profiles of Figure 4 or calculated from other field measurements (Fig. 8; Table 1). Maximum dip-slip components of 5 to 6.5 m occur along the southern part of the scarp. Dip slip diminishes northward, particularly beyond the Los Angeles Aqueduct. Parts of the scarp between profile 14 and Los Angeles Aque-duct (Fig. 6) do not show total dip slip because of significant deposition of sediment from LPC 2 (Fig. 2) along the base of the scarp in this area. The 1872 component of dip slip has not been significantly obscured along this segment, however.

If the 1872 earthquake is a characteristic event (as defined by Schwartz and Coppersmith, 1984) for this fault during late Quaternary time, the comparison of total dip slip to 1872 dip slip indicates that a total of three 1872-type slip events have produced the present fault scarp. This

LATE QUATERNARY ACTIVITY, LONE PINE FAULT, CALIFORNIA 7 6 1

Figure 8. Method used to estimate dip slip component of Lone Pine scarp at measurement sites shown in Figure 6. Scarp height, Y, and width, X, were measured graphically from scarp pro-files or with plane table and alidade (Table 1). Yj, dip slip for assumed ver-tical fault; Y2, dip slip for fault with assumed 70° dip. For all estimates of dip slip, we assumed a = /? = 4°.

f a n s u r f a c e Q ; i an sur

pro jec ted fault p lanes

^ f a n s u r f a c e

conclusion is supported by the position of coatings on a 3 x 5 m boulder exposed in the scarp between profiles 12 and 13 (Fig. 6). This boulder records at least three slip events (Fig. 9).

Interpretation of the sedimentary record exposed in the backhoe trench also is consistent with three slip events (Fig. 7). East of the main fault and scarp exposed in the trench wall, there is a 6.5-m-wide graben that has been filled by debris shed primarily from the west. The stratig-raphy exposed in the trench wall suggests that this graben formed during two pre-1872 slip events but did not deepen in 1872. The oldest slip event is recorded by the step-like offsets of the surface of the original outwash fan deposit (unit F) and the increased thickness of the part of the subsequent wash deposit (unit C) that occupies the graben relative to the thickness of unit C east of the graben. A second earthquake with associated deepening of the graben is recorded by the similar increased thickness of the next younger wash deposit (unit B) within the graben and by the east-side-up step in the contact between units B and C. This east-side-up step was produced by slip along the fault shown at horizontal station 6.2 in Figure 7A. The low scarp that developed in unit C along this fault (3, Fig. 7B) was eroded, and the material was redeposited immediately to the west (4, Fig. 7B); hence this fault does not project vertically through unit C. The faults at the east end of the graben apparently did not rupture in 1872, because unit B, which predates the 1872 earthquake, is not offset.

We could not find a contact within the older debris deposit (unit D) to evince its formation from two earthquakes. We found little evidence for soil development in unit D or any of the units exposed by the trench, including the relatively stable parts of unit F, which have been exposed longest to soil-forming processes. Finding such a contact in colluvial de-bris, without soil formation, might expectably be difficult.

The large boulder shown in profile 11 (Fig. 4) suggests that the latest large event before 1872 produced about as much vertical offset as did the 1872 event. The desert-varnish coating on this boulder above the ring is

Figure 9. Boulder in scarp of Lone Pine fault that apparently records three slip events. Line A separates areas of different weather-ing and coincides with the projection of the original upper-fan surface. The part of this boulder above line A apparently lay above the ground surface before scarp development. Two rings of desert varnish, B and C, may record later stable positions of the ground surface, each fol-lowing prehistoric faulting. Rod is 1.5 m long. View north between profiles 12 and 13 (Fig. 6).

TABLE 1. DIMENSIONS AND CUMULATIVE DIP SLIP OF LONE PINE SCARP

Location* Scarpî Scarpt Cumulative dip slip§ height (Y) width (X) 90° 70°

1 6.2 17 5.0 5.5 2 16.8 4.1 4.5 3 10.8 3.2 3.5 4 + 5 17.6 3.9 4.3 6 13.9 5.0 5.5 7 13.2 4.4 4.8 8 15.2 4.4 4.8 9 18.4 5.0 5.5

10 13.6 4.8 5.2 11 13.6 2.8 3.1 12 12.0 3.2 3.5 13 15.8 3.6 3.9 14 8.8 2.2 2.4 15 9.0 2.1 2.3 16 8.8 0.5 0.5 17 18.0 0.6 0.7 18 14,2 0.6 0.7 19 7.0 0.2 0.2

*At measurement sites of Figure 6. tin metres; see Figure 8. -In metres; calculated as shown in Figure 8 for assumed fault dips of 90° and 70°.

762 LUBETKIN AND CLARK

fairly uniform, suggesting that the boulder was completely buried before the latest pre-1872 event. If the upper scarp surface does approach some stable form as seen in the historic record, then that surface must have been above the boulder before the earlier event. Otherwise, a darker zone of varnish would likely be present over that part of the boulder exposed for a longer time. Reconstruction of profile 11 suggests a minimum value for vertical offset accompanying a pre-1872 event of about 1 m (Fig. 4).

Our estimate of the number of earthquakes recorded in the scarp assumes that all surface displacement results from sudden coseismic slip with possibly some afterslip, rather than long-term creep. We also assume that this fault experiences recurrent great earthquakes, rather than many small to moderate earthquakes accompanied by small surface slip.

We have not been able to document modern creep on either the Lone Pine fault or the Owens Valley fault, although Bonilla (1968) inferred the possibility of post-1872 creep on both. Repeated surveys show no dis-placement of the aqueduct at the Lone Pine fault (Fig. 2), in spite of local cracks in the canal liner (R. G. Wilson, Los Angeles Department of Water and Power (LADWP), 1986, personal commun.). Surveyed lines span-ning the Lone Pine fault and associated faults east of it show no fault creep from 1968 to 1986 (H. Mayeda and R. McGhie, LADWP, 1987, personal commun.). Photographic evidence and field observations also indicate a lack of creep along this fault during the past 70 to 80 yr. In addition, we could find no reports of creep offset of streets, utilities, or houses along the main Owens Valley fault trace.

COMPONENT OF HORIZONTAL SLIP

Although the scarp across the abandoned fan is testimony to a large vertical component of slip, the horizontal component at this scarp is much larger. We measured this horizontal component of slip from an offset relict

channel and an offset debris flow (LPC 3 and D, Fig. 6). The channel apparently predates the scarp and has thus been offset by three events. The debris flow is younger and has been offset by only two events. This interpretation of the relict channel and offset debris flow differs from that in earlier reports (Lubetkin, 1980; Lubetkin and Clark, 1985) and is the result of additional field study.

Offset Relict Channel

The oldest large channel developed in the fan, LPC 3 (Figs. 2, 6) is partly buried in the graben east of the scarp, but it has been cut to similar depth in both the upthrown block west of the scarp and in the rest of the abandoned fan east of the graben. Incision in the upthrown block in response to faulting is minor near the scarp. The channel does not show a major erosional response to faulting because it was probably abandoned before creation of the scarp. Although we could not readily identify the center of the channel in the graben, we estimate 12 to 18 m of right-lateral offset of the top of the north margin of the channel at the scarp (Fig. 10). The north channel wall west of the scarp, on the relatively upthrown block, is well defined; however, in the graben this wall is less distinct and has a larger uncertainty in its projection to the fault (Fig. 10). We assume that this channel shows cumulative horizontal offset from the three earth-quakes identified from analysis of the dip-slip component. If three events created the horizontal offset of this channel, the average horizontal com-ponent for each would be 4 to 6 m (Table 2).

The arcuate, subparallel normal faults at the eastern side of the graben offset this channel vertically, but not horizontally along strike. The channel curves to the left downstream in the graben, lending a false ap-pearance of left-lateral offset at its eastern margin (Fig. 2).

LPC 3 is the channel shown in Plate XXb of Hobbs (1910), described

Figure 10. View west along LPC 3 (Fig. 2) toward scarp of Lone Pine fault, showing 12 to 18 m of right-lateral offset of top of north wall of channel. Dashed lines in foreground show our estimate of the extreme range in likely position of top of pre-offset channel wall in the graben east of fault, projected westward to scarp. Dashed line down face of scarp is eastward projection to the base of scarp from top of channel wall that lies west of the fault; tics near base of scarp show ±1 m, our estimate of uncertainty in this projected position. Estimated offset assumes uniform and equal post-offset erosion of channel walls and continuation of pre-offset channel walls straight to the fault trace, as in our projections. W. D. Johnson photo 690, USGS Library, Denver; nearly identical to W. D. Johnson photo 686, which appears in Hobbs (1910) as Plate XXb.

LATE QUATERNARY ACTIVITY, LONE PINE FAULT, CALIFORNIA

TABLE 2. MEASURED A N D CALCULATED SLIP AT LPC 3 A N D DEBRIS FLOW, LONE PINE SCARP

763

Horizontal Dip Total Average/Event^ component* component* slipt _

Horizontal Dip Total component component slip

LPC3§

Crest of lateral 10.3 11.2 2.2 2.4 10.5 deposit

Debris flow **

Medial channel 10.5 12 1.7 1.9 10.5

11.5 5.2 5.6 1.1 1.2 5.3 5.8

>12 5.3 6 5.3 > 6

Note: data in metres.

•Measured.

•¡Calculated. SThrce events. Horizontal component measured at north wall of channel (Fig. 10); dip component taken from profile 11 (Fig. 6). **Two events. Horizontal component measured for two possible fault positions, at the base of, and at the top of, scarp; dip component measured for two possible fault dips, 70° and 90°. Dip component of medial channel not used for total slip

(see text).

there as showing 20 ft (~6 m) of right offset. Bateman (1961) challenged this interpretation because he could see neither field evidence for this offset nor find reference to it in W. D. Johnson's unpublished notes in U.S. Geological Survey (USGS) archives. Indeed Bateman (1961) quoted Johnson's unpublished statement that this scarp showed no evidence for horizontal offset. We have obtained further information from Johnson's letters to Hobbs, however. These letters form the basis for much of Hobbs' paper (Hobbs, 1910, p. 354) and are in the University of Michigan Li-brary. In his letter to Hobbs of May 29,1907, Johnson recorded "sugges-tions of lateral movement..." of this channel of " . . . about 20 feet." This part of Johnson's letter clearly is the basis for the caption of Hobbs' Plate XXb. Johnson's later statement in USGS archives is apparently wrong; it contradicts his own field observations and ours. Offset of the eroded channel margins is subtle but distinct on aerial photos and discernible in the field. An intriguing possibility is that Johnson saw a 20-ft offset of a

young, ephemeral part of the channel. A 20-ft (~6 m) horizontal offset is within our 3-event average horizontal offset of 4 to 6 m at LPC 3.

Offset Debris Flow

A debris flow complex that fills much of the northern relict channel of the fan (LPC 2, Fig. 2) has also been offset by the Lone Pine fault. This complex consists of many individual tongue-like masses of metamorphic debris derived from the Alabama Hills. These debris flows invaded the abandoned channel of LPC 2 and followed it to the scarp. One of the most recent debris flows has been offset right laterally 10.3 to 12 m and verti-cally 2.2 to 2.4 m, east side down (younger debris flow, Fig. 11) where it crosses the Lone Pine fault. Net oblique offset of this debris flow is 10.5 to >12 m (Table 2).

The common debris-flow components, such as coarse-grained lateral

Figure 11. Geologic map of offset debris flow along Lone Pine fault. Lo-cation shown on Figure 6.

EXPLANATION

Alluvium (Holocene)

Debris der ived f rom scarp (Holocene)

Younger debris f low (Holocene)

Medial channel deposi ts

[ | Lateral deposi ts

0 L

meters Contour Interval 1 m

Arb i t rary Datum

Older debris f low (Holocene)

Alluvial fan (Pleistocene!) — Composed primarily of glacial outwash

/ con tac t , dashed where approximately / located

top of fault scarp , A hachures point downslope

large granitic boulder

7 6 4 LUBETKIN AND CLARK

deposits and fine-grained medial channel deposits (Johnson, 1965; Jahns, 1949), are obvious and have sharp boundaries. The outer flank of the lateral deposit is not as steep as on most fresh debris flows of similar coarseness. The scarcity of matrix at the surface suggests some deflation of the lateral deposits.

The narrow graben at the base of the east-facing fault scarp conceals the immediate continuation of the lateral deposit and the medial channel, so that the offsets cannot be precisely measured. We projected the trends of the crest of the lateral deposit and the medial channel across the graben from the downthrown block to estimate their offsets, however.

We measured both the horizontal and dip-slip components of fault offset of this youngest debris flow along the crest of the southern lateral deposit and alongthe medial channel. We did not use the dip-slip compo-nent of offset of the medial channel because of possible post-offset erosion and deposition of its relatively fine material, and we did not use offset of the southern margin of the lateral deposit because of possible postdeposi-tional alteration.

The dip-slip component of offset of the debris flow indicates that it has been offset by two events. Although we cannot deduce 1872 dip slip from the scarp profile at the debris flow, 1872 dip slip at flanking locations (P 15 and 71, Fig. 6) is 0.8 to 1.6 m, about half of the dip slip of the crest of the south lateral deposit of the debris flow, 2.2 to 2.4 m. This relation-ship of dip slip indicates that two events have offset the debris flow. Horizontal offset of the debris flow, 10.3 to 12 m, also suggests two events. Average horizontal slip for two events would be 5.2 to 6 m, which is within the range of average horizontal slip of 4 to 6 m for three events at the offset channel (LPC 3) 200 m to the south (Table 2).

AGE OF THE ABANDONED FAN SURFACE

Shorelines of Pleistocene Lake Owens are older than the abandoned outwash fan. Gravelly beach deposits with some tufa coatings and low wave-cut cliffs of this lake are preserved along short reaches of the eastern flank of the Alabama Hills at a maximum elevation of 1,144 m. These shoreline features record a temporary highstand of Lake Owens. The old shoreline does not cut the surface of the abandoned fan, nor does geomor-phic or sedimentary evidence indicate that the fan was built into a lake at this high-water stand. The abandoned fan surface therefore postdates the highstand of the lake.

Lithoid tufa from the beach gravels yields a 14C age of 21,000 ± 130 yr (USGS 609, Fig. 1). We took this sample from near the stratigraphic top of the shoreline deposit. It gives an approximate age for the highstand of the lake and a maximum age for the fan surface.

14C dates from tufa can be in error because of contamination by later atmospheric carbon or the presence of older carbon in the lake water. The date, however, is consistent with the record from downstream Lake Searles and from Pleistocene lakes of the Great Basin. The continuous highstands of Lake Searles from - 2 4 to 17 ka required overflow from Lake Owens (Smith, 1976,1983; Smith and Street-Perrott, 1983), although the record from Searles Lake indicates Lake Owens also overflowed from 12 to 10 ka (Smith and Street-Perrott, 1983). In addition, Lakes Lahontan and Bonne-ville, in the Great Basin, had highstands 16.5 and 13.5 to 12.5 ka, respec-tively (Scott and others, 1983; Thompson and others, 1986; Benson and Thompson, 1987), and Lake Russell (Pleistocene Mono Lake) had its last highstand 14 to 12 ka (Lajoie and Robinson, 1982). If younger carbon has contaminated the tufa, the shoreline could possibly represent an older, early Wisconsin lake, but in the absence of additional information, we provisionally accept 21 ka as the maximum age of the surface of the abandoned Lone Pine fan.

Techniques that determine relative age provide a minimum age for the surface of the Lone Pine fan. The amount of sculpting and degree of weathering of granitic boulders, soil-oxidation color, and fan surface mor-

phology indicate a latest Pleistocene age for the surface of the abandoned Lone Pine fan. In addition, these criteria for relative dating demonstrate that the abandoned fan surface is younger than the surface of the alluvial fans west of the Alabama Hills, which we consider to be 150 to 50 ka.

Boulders larger than 0.5 m exposed on the surface of the abandoned fan show ~ 5 to 30 mm of weathering relief (Fig. 12). This relief is expressed by protruding mafic inclusions and dikes, large feldspar pheno-crysts, and by a slight bell-like configuration at the base of boulders (indi-cating greater weathering and erosion above ground). Boulders of similar granitic lithology located on the surface of fans west of the Alabama Hills show greater weathering relief of 30 to 150 mm (Fig. 12) and a more exaggerated bell shape. In contrast, those on the Holocene Lone Pine fan, east of the Alabama Hills and south of the abandoned fan, show less than 5 mm of weathering relief; inclusions and dikes commonly are flush with the surrounding boulder surfaces.

Granular disintegration of buried granitic boulders also indicates that the alluvial fans west of Alabama Hills are older than the abandoned fan of Lone Pine Creek. The fans west of Alabama Hills have a greater percen-tage of disintegrated or partially disintegrated granitic clasts, a relationship used to separate glacial deposits of different ages (Birman, 1964; Burke and Birkeland, 1979). From 5% to 50% of the subsurface granitic clasts at six locations in the fan deposits west of the Alabama Hills are at least slightly disintegrated, whereas fewer than 5% of the subsurface granitic clasts of the abandoned fan in soil pits are slightly disintegrated.

The degree of weathering of the fans west of the Alabama Hills suggests that they are contemporary with moraines of the Tahoe glaciation (ca. 150 to 50 ka; Burke and Birkeland, 1979; Dorn and others, 1987) of the eastern Sierra Nevada. This agrees with the conclusions of Knopf (1918) and Richardson (1975). The criteria of relative age are internally consistent and indicate that the abandoned Lone Pine fan is distinctly younger than the fans west of the Alabama Hills.

We consider the abandoned Lone Pine fan to be contemporary with the younger (Tioga) glaciation, which ended about 10 ka (Adam, 1967; Mezger and Burbank, 1986). Weathering on this fan is similar to that on deposits of the Tioga glaciation along the eastern slope of the Sierra Nevada. The modern channel of Lone Pine Creek has incised nearly 20 m into the head of the abandoned fan and about 10 m into the upstream terraces. This major incision suggests that Lone Pine Creek had the dis-charge and competence of glacial or final glacial conditions at the time of abandonment. Yet the relatively small size of the modern fan of Lone Pine Creek precludes a large content of primary outwash. These observations indicate that abandonment was near the end of the Tioga glaciation. Because large amounts of outwash would have been produced up to the end of the Tioga glaciation, we consider that most of the fan surface is relatively young, probably closer to 10 ka than to 21 ka.

Although the youngest channel on the fan, LPC 2, continued to be active after the first faulting event, LPC 2 is a late feature of the fan. Its channel and associated deposits cover less than about 5% of the fan surface west of the scarp. Hence most of the fan surface was constructed before LPC 2 came into relatively brief use before abandonment.

Thus the tufa-dated shoreline, the regional record of Pleistocene lakes, and relative weathering strongly indicate that the faulted surface of the abandoned fan of Lone Pine Creek is between 10 and 21 ka, probably closer to 10 ka.

LATE QUATERNARY RECURRENCE INTERVALS AND SLIP RATES

The fault offset and postulated earthquake history recorded by the scarp permit us to calculate average late Quaternary recurrence intervals and slip rates, although we have not dated individual events. Three slip events since 10 to 21 ka give minimum and maximum average recurrence

LATE QUATERNARY ACTIVITY, LONE PINE FAULT, CALIFORNIA 765

A < > cc LU

co en <

DC

z (n cc LU a - j

3 o CD

Z U J O IT

ABANDONED LONE PINE FAN

SURFACE

100-,

50-

0 1 0 0 i

50'

0 100

50-

0 100

50

0

1 0 0 -

50-

0

1

= 1 30 60 90

FAN SURFACE WEST OF ALABAMA HILLS -

FAN SURFACE WEST OF ALABAMA HILLS -

SUBDUED MORPHOLOGY DISTINCT MORPHOLOGY

30 60 90 120 150 180

MAXIMUM WEATHERING RELIEF IN MILLIMETERS

B

Figure 12. Maximum weathering relief of granitic boulders on fan sur-faces near Lone Pine. A. Graphs presenting the measurements of maxi-mum weathering relief on at least 50 granitic boulders at each test site (1 to 10). Weathering relief measurements are grouped into 30-mm increments. B. Locations (1 to 10) of boulder-weathering test sites. See Figure 1 for explanation of symbols.

intervals along the Lone Pine fault of 5,000 and 10,500 yr. The 5,000-yr interval assumes that most of the fan surface was deposited about 10 to 15 ka, and the first earthquake happened shortly before abandonment at 10 ka. The next pre-1872 event then occurred about 5 ka. The 10,500-yr interval assumes that most of the fan was deposited about 21 ka, just before the first earthquake. The next pre-1872 event then occurred about 10.5 ka, just after abandonment. We favor the shorter recurrence interval.

Scarp morphology suggests that the calculated recurrence intervals are reasonable. The maximum slope for the youngest pre-1872 scarp ranges from 30° to 38° and is distinctly less than the maximum slope angle for the 1872 portion of the scarp ( - 7 0 ° to 90°). The time required to modify the scarp formed in the last pre-1872 rupture event to its 1872 shape is the true interval between those two events. The interval between those slip events appears to be much longer than the 115 yr since the 1872

earthquake, on the basis of differences in maximum slope angles and evidence of low erosion rates on gentler slopes. The actual erosion rate, and its variations with time and slope, are unknown; hence this time interval cannot be directly measured.

We combine the range of recurrence interval with the range of aver-age total slip/event2 from Table 2, 4.3 to 6.3 m, to estimate the range of slip rates allowed by our data (Clark and others, 1984). The extremes of

2 Although we use the full dip-slip component to estimate the number of events and recurrence, the slip-rate calculation should use a smaller dip-slip component, because our measurements are from one side of a shallow graben (Fig. 2). Net dip slip across this graben is possibly as little as one-half of the dip slip reported here for its west side. Because the horizontal component dominates net slip, however, and in view of the large uncertainties in our age estimates, the effects of this uncertainty in graben depth on slip rate are not significant.

766 LUBETKIN AND CLARK

these ranges yield slip rates between 0.4 and 1.3 mm/yr. Because we think the fan surface is probably closer to the minimum rather than the maxi-mum age, we favor the larger values in this range.

RELATIONSHIP OF THE LONE PINE FAULT TO THE OWENS VALLEY FAULT ZONE

Because the Lone Pine fault is only one of several strands within the Owens Valley fault zone, the late Quaternary average recurrence interval for major earthquakes, the range of slip rates, and the nature of slip for the Lone Pine fault do not necessarily represent activity for the entire fault zone. Information on relationships among the various faults in the zone, and on changes in these relationships with time, are necessary for a com-plete analysis. The information we now have, however, allows us to make some preliminary estimates about behavior of the fault zone.

The Lone Pine fault shows a large vertical component of recent displacement in the region where the main Owens Valley trace does not. A prominent east-facing scarp marks the main Owens Valley trace from near the north end of the adjacent Lone Pine fault to the north end of the Alabama Hills (Fig. 1). The Lone Pine fault apparently accommodates local vertical displacement along the Owens Valley fault zone. This rela-tionship does not necessarily indicate that the two faults rupture concur-rently, but that the vertical component of displacement has been consistently distributed between them in late Quaternary time.

TOTAL 1872 SLIP, HOLOCENE SLIP RATE, AND RECURRENCE FOR THE OWENS VALLEY FAULT ZONE

Adding the estimated 1872 horizontal component of slip along the Lone Pine fault, 4 to 6 m (Table 2), to the measured 1872 horizontal component of slip on the Owens Valley fault in Lone Pine of 2.7 to 4.9 m (9 to 16 ft, Bateman, 1961; Hobbs, 1910) gives a maximum 1872 horizon-tal-slip component approximately between 7 and 11 m for the Owens Valley fault zone at Lone Pine. Adding all or part of the dip-slip compo-nent of 1872 on the Lone Pine fault (1 to 2 m) does not significantly increase the total slip. This combined strike slip across the fault zone is large. It is comparable to the maximum strike slip of ~9.5 m reported for the great Fort Tejon earthquake of 1857 on the San Andreas fault (Sieh, 1978).

If we assume further that the Lone Pine fault characteristically rup-tures at the same time as the Owens Valley fault, as it did in 1872, we can calculate a Holocene horizontal-slip rate for the Owens Valley fault zone at Lone Pine. Dividing the assumed characteristic total horizontal-slip com-ponent of 7 to 11 m at Lone Pine by the average recurrence interval for such an earthquake, 5,000 to 10,500 yr, gives an average horizontal-slip rate of 0.7 to 2.2 mm/yr. This slip rate is near the average historic right-lateral displacement rate of about 3 to 7 mm/yr measured geodetically by Savage and others (1975) for 1928 to 1974 and by Savage and Lisowski (1980) for 1974/1975 to 1979 between bench marks that span Owens Valley. This rate is also about the same as the maximum reported for normal faults of the Sierran range-front northwest of Owens Valley and is near the known maximum for any dextral strike-slip or normal fault of this region (Clark and others, 1984).

ACKNOWLEDGMENTS

This report is based on Lubetkin (1980) and Lubetkin and Clark (1985), with additional field investigations in 1985 and 1986, assisted by K. K. Harms and S. K. Pezzopane. Lubetkin's original field work was funded in part by the Shell Fund of Stanford University. We conferred

extensively with Sarah Beanland of New Zealand Geological Survey about her work in Owens Valley. We have benefited from discussions with P. C. Bateman, M. G. Bonilla, A. R. Gillespie, R. H. Jahns, K. R. Lajoie, D. P. Schwartz, G. I. Smith, and R. E. Wallace; and reviews by M. G. Bonilla, S. J. Martel, K. E. Sieh, and R. J. Weldon.

R E F E R E N C E S C I T E D

Adam, D. P., 1967, Late-Pleistocene and Recent palynology in the central Sierra Nevada, in Cushing, E. J., and Wright, H. E., Jr., eds., Quaternary Paleoecology: INQUA Congress VII, Proceedings 7, Yale University Press, p. 275-301.

Bateman, P. C., 1961, Willard D. Johnson and the strike-slip component of fault movement in the Owens Valley, California earthquake of 1872: Seismological Society of America Bulletin, v. SI, p. 483-493.

Beanland, Sarah, and Clark, M. M., 1987, The Owens Valley fault zone, eastern California, and surface rupture associated with the 1872 earthquake [abs.]: Seismological Society of America, Seismological Research Letters, v. 58, p. 32.

Benson, L. V., and Thompson, R. S., 1987, Lake-level variation in the Lahontan Basin for the past 50,000 years: Quaternary Research, v. 28, p. 69-85.

Birkeland, P. W., 1974, Pedology, weathering and geomorphological research: New York, Oxford University Press, 285 p. Birman, J. H., 1964, Glacial geology across the crest of the Sierra Nevada, California: Geological Society of America

Special Paper 75,80 p. Bonilla, M. G., 1968, Evidence for right-lateral movement on the Owens Valley, California, fault zone during the

earthquake of 1872, and possible subsequent fault creep: Conference on Geological Problems of the San Andreas Fault System, Proceedings, Stanford University Publications in the Geological Sciences, v. 11, p. 4-5.

Burke, R. M., and Birkeland, P. W., 1979, Réévaluation of multiparameter relative dating techniques and their application to the glacial sequencealongtheeastern escarpment of the Sierra Nevada, California: Quaternary Research, v. 11, p. 21-51.

Carver, G. A., Slemmons, D. B., and Glass, C. E., 1969, Surface faulting patterns in Owens Valley, California: Geological Society of America Abstracts with Programs for 1969, v. 1, no. 3, p. 9-10.

Clark, M. M„ Harms, K. K„ Lienkaemper, J. J„ Harwood, D. S„ Lajoie, K. R„ Matti, J. C , Perkins, J. A , Rymer, M. J., Sarna-Wojcicki, A. M., Sharp, R. V., Sims, J. D., Tinsley, J. C., and Ziony, J. I., 1984, Preliminary slip-rate table and map of late-Quaternary faults of California: U.S. Geological Survey Open-File Report 84-106.

Dora, R. I., Bamforth, T. A., Cahill, T. A., Dohrenwend, J. C , Turrin, B. D„ Donahue, D. J., Jull, A.J.T, Long, A., Macko, M. E., Weil, E. B., Whitley, D. S., and Zabel, T. H., 1986, Cation-ratio and accelerator radiocarbon dating of rock varnish on Mojave artifacts and landforms: Science, v. 231, p. 830-833.

Dom, R. I., Turrin, B. D., Jull, A.J.T., Linick, T. W., and Donahue, D. J., 1987, Radiocarbon and cation-ratio ages for rock varnish on Tioga and Tahoe moraina! boulders of Pine Creek, eastern Sierra Nevada, California, and their paleoclimatic implications: Quaternary Research, v. 28, p. 38-49.

Gilbert, G. K., 1884, A theory of the earthquakes of the Great Basin, with a practical application: American Journal of Science, 3rd series, v. 27, p. 49-53.

Hobbs, W. H., 1910, The earthquake of 1872 in the Owens Valley, California: Beitrage zur Geophysik, v. 10, p. 352-385. Jahns, R. H., 1949, Desert floods: Engineering and Science Monthly, v. 12, no. 8, p. 10-14. Johnson, A. M., 1965, A model for debris flow [Ph.D. thesis]: University Park, Pennsylvania, The Pennsylvania State

University, 248 p. Knopf, A., 1918, A geologic reconnaissance of the Inyo Range and the eastern slope of the southern Sierra Nevada,

California: U.S. Geological Survey Professional Paper 110,130 p. Lajoie, K. R., and Robinson, S. W., 1982, Late Quaternary glacio-lacustrine chronology, Mono Basin, Calif.: Geological

Society of America Abstracts with Programs, v. 4, p. 179. Lubetkin, L.K.C., 1980, Late Quaternary activity along the Lone Pine fault, Owens Valley fault zone, California [M.S.

thesis]: Stanford, California, Stanford University, 85 p. Lubetkin, L.K.C., and Clark, M. M., 1985, Late Quaternary activity along the Lone Pine fault, eastern California, in Stein,

R. S., and Bucknam, R. C., eds., Proceedings of Workshop XXVIII on the Borah Peak, Idaho earthquake: U.S. Geological Survey Open-File Report 85-290, p. 118-140.

Martel, S. J., 1984, Late Quaternary activity on the Fish Springs fault, Owens Valley fault zone, California [M.S. thesis]: Stanford, California, Stanford University.

Martel, S. J., Harrison, T. M., and Gillespie, A. R., 1987, Late Quaternary vertical displacement rate across the Fish Springs fault, Owens Valley, California: Quaternary Research, v. 27, p. 113-129.

Mezger, L., and Burbank, D., 1986, The glacial history of the Cottonwood Lakes area, southeastern Sierra Nevada: Geological Society of America Abstracts with Programs, v. 18, p. 157.

Oakeshott, G. B., Greensfelder, R. W„ and Kahle, J. E„ 1972, 1872-1972 . . . one hundred years later: California Geology, v. 25, p. 55-61.

Richardson, L. K., 1975, Geology of the Alabama Hills, California [M.S. thesis]: Reno, Nevada, University of Nevada. Richter, C. F., 1958, Elementary seismology: San Francisco, W. H. Freeman, 768 p. Savage, J. C., and Lisowski, M., 1980, Deformation in Owens Valley, California: Seismological Society of America

Bulletin, v. 70, no. 4, p. 1225-1232. Savage, J. C., Church, J. P., and Prescott, W. H., 1975, Geodetic measurement of deformation in Owens Valley,

California: Seismological Society of America Bulletin, v. 65, no. 4, p. 865-874. Schwartz, D. P., and Coppersmith, K. J., 1984, Fault behavior and characteristic earthquakes: Examples from the

Wasatch and San Andreas fault: Journal of Geophysical Research, v. 89, p. 5681-5698. Scott, W. E., McCoy, W. D., Schroba, R. R., and Rubin, M., 1983, Reinterpretation of exposed record of the last two

cycles of the Lahontan Basin, western United States: Quaternary Research, v. 20, p. 261-285. Sieh, Kerry, 1978, Slip along the San Andreas fault associated with the great 1857 earthquake: Seismological Society of

America Bulletin, v. 68, no. 5, p. 1421-1448. Slemmons, D. B., and Cluff, L. S., 1968, Historic faulting in Owens Valley, California: Geological Society of America,

Special Paper 121, Abstracts for 1968, p. 559-560. Smith, G. I., 1976, Paleoclimatic record in the upper Quaternary sediments of Searles Lake, California: Paleolimnology of

Lake Biwa and the Japanese Pleistocene, v. 4, p. 577-603. 1983, Core KM-3, a surface-to-bedrock record of late Cenozoic sedimentation in Searles Valley, California: U.S. Geological Survey Professional Paper 1256,23 p.

Smith, G. I., and Street-Perrott, F. A., 1983, Pluvial lakes of the western United States, in Wright, H. E-, Jr., ed., Late-Quaternary environments of the United States: Minneapolis, University of Minnesota Press, v. 1, chap. 10, p. 190-212.

Smith, R.S.U., 1979, Holocene offset and seismicity along the Panamint Valley fault zone, western Basin and Range province, California: Tectonophysics, v. 52, p. 411-415.

Thompson, R. S., Benson, L., and Hattori, E. M., 1986, A revised chronology for the last Pleistocene lake cycle in the central Lahontan basin: Quaternary Research, v. 25, p. 1-9.

Townley, S. D., and Allen, M. W., 1939, Descriptive catalogue of earthquakes of the Pacific Coast of the United States 1769-1928: Seismological Society of America Bulletin, v. 29, p. 1-297.

Wallace, R. E., 1977, Profiles and ages of young fault scarps, north-central Nevada: Geological Society of America Bulletin, v. 88, p. 1267-1281.

Whitney, J. D„ 1872, The Owens Valley earthquake: Overland Monthly, v. 9, p. 130-140,266-278. Zoback, M. L., and Beanland, Sarah, 1986, Stress and tectonism along the Walker Lane belt, western Great Basin [abs.]:

EOS (American Geophysical Union Transactions), v. 67, p. 1225.

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