/
GARY S. RASMUSSEN" & ASSOCIATES /ENGINEERING GEOLOGY
1906 50. C:OMMl\:RCE:NTE:R EAST, SUITE 207 • SAN BERNARDINO, CA 92408 • C714) 888·2422 • (7141 a:z~"90!:52
September 27, 1979
Camp Teresita P:ines 22801 Big Pines Highway Wrightwood, California 92397
Attention: Ralph Hul lman
Subject: Addendum to Our Report flated August 31, 1979.
Project No. 1551-2
Reference: Engineering Geology Investigation, Dining Hall Addition, Camp Teresita Pines, 22801 Big Pines Highway, Wrigthwood, California, Our Report Dated August 31, 1979, Project No. 1551.
The following modification and additions should be made to the referenced
report in response to questions by Mr. [)avid Popplar, County of Los Angeles,
Engine'ering Geology Section.
Page 6, Linc 6. The fol_lowing sentence should be added, "The fault appears
to be at least 100 feet south of the proposed dining hall addl ti on, based
on the projection of aerial photographic lineaments observed both northwest
and southeast of the site." The last sentence of this paragraph should be
modified to, "It is remotely possible that during a major event on the
San Andreas fault, approximately 800 feet south of the proposed <lining hall .
addition, minor differential settlement or sympathetic movement of the
order of approximately \ inch per 30 feet normal to the fault could occur
along the old fault trace." '
Page 10. Tiie second pa:ragraph under Recommendations should be changed to,
"A slight poss:ibi.lity for sypmathetic movement or differential settlement
along the older, inactive fault which projects approximately l 00 feet
south of the proposed building site is possible. This potential settlement
wi 11 probably not affect the proposed dining hall addition, and the maxiJUum
expected differential settlement along the fault is expected to be of the
order of \ inch per 3_0 feet normal to the fault.-"
OCT O 2197g
Camp Teresita Pines -Addendum September 27, 1979
Project No. 1551-2
Page 10. The following sentence should be "dded to the third paragraph
under Recommendations, "The recommended setback from the steep slopes
will not affect the proposed dining hall addition."
TES:GSR/mt
Respectfully submitted,
GARY S. RASMUSSEN & ASSOCIATES, INC.
~c.S~ Thomas E. Spittler Staff Geologist
Gary S. Rasmussen Engineering Geologist, EG 925
Distribution: Teresita Pines, L.A. (5)
Los Angeles County, Engineering Geology Section (2) Attn: Dave Popplar
-2-G.ARY S. RASMUSSEN & .ASSOCIATES
STATE OF ('.Al!rORNIA-iHE R~50URcrs AGENCV EOMUNO G. Sl?OWN JR,, Ga~ntor
DEF"AR<MENT Of CONSERVATION
DIVISION OF MINES AND GEOLOGY SAN FRANCISCO DISTRICT OFFICE FERRY SUllDING
SAN fJl'ANCfSCO. CA 94111
(Ph.one 4 l!i-557-0633} AfJ-ID37
November 5, 1979
Mr. Poppler Engineering Geology Section 550 South Vermont Avenue Los Angeles, California 90020
Dear Mr. Poppler:
We are placing on open file the following reports, reviewed and approved by the City of Los Angeles in compliance with the Alquist-Priolo Special Studies Zones Act:
//-=--, ··/1.'J-.) Engineering Geology Investigation, Dining Hall Addition, (_~ Camp Teresita Pines, 22801 Big Pines Highway, Wrightwood,
California: Gary S. Rasmussen & Associates, August 31, 1979, -Project No. 1551, 15 p.
2. Geologic Reconnaissance, .39120 Bouquet Canyon Road, Leona Valley, California: Michael V. Smith, Engineering Geologist, File No. 7958-1, October 16, 1979, 7 p.
3. Fault Study, Tax Parcel Number 3052-30-26, Palmdale, California: Michael V. Smith, Engineering Geologist, File No. 78-33, November 13, 1978, 9 p.
4. Fault Study, Tax Parcel Number 3052-18-23, Palmdale, California: Michael V. Smith, Engineering Geologist, File No. 7940-1, July 26, 1979, 8 p.
For your information: Site location maps are missing for reports 2, 3 and 4 listed above.
TLB/fnl
cc: A-P file ( ~)
Sincerely yours,
TRINDA L. BEDROSSIAN Office of the State Geologist RG 3363
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[~] Plan approved subject to conditions below Submit plans for te-ch~ck
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Remarks:
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I I I I I I I I I I I I I I I I I I I
ENGINEERING GEOLOGY INVESTIGATION DINING HALL ADDITION
CAMP TEREClTA PINES 22801 JUG PINES HIGHWAY WRlGHTl~OOD, CALIFORNIA
August 31, 1979
Project No. 1551
P mp a red for
Camp Terecita Pines 22801 Big Pines Highway Wrightwood, California
I I I I I I
I I I I I I I I I I
•• I
GARY S. RASMUSSEN & ASSOCIATES /ENGINEERING GEOLOGY
1!)06 so. COMME:RCENTER EAST, SUITE 20'7 • SA.N El!::RNARDINO, CA 92408 ~ (714) eee-242.2. • (714) 825·90~.2
August 31, 1979
Camp Tereci ta f'i.nes 22801 Big Pines Highway Wrightwood, California 92397
Att: Ralph Hullman
Project No. 1551
Subject: Dining Hall Addition, Camp Terecita Pines, 22801 Big Pines Highway, Wrightwood, California.
An engineering geology investiga.tion of the proposed dining hall addition for
Camp Terecita Pines has been conducted at your request. The purpose of our
investigation was to determine the geology of the area and to assess any poten
tial geologic hazards to the proposed rebuilding of the dining hall addition.
We understand the new dining hall will be built on the existing foundation.
The former dining hall, built on the same foundation apparently collapsed in
February 1974 due to snow and wind loads. Camp Tereci ta Pines is located on
the north side of Big Pines Highway, east of Jackson Lake, in the Big Pines
recreation area of the Angeles National Forest. The camp is on the north facing
slope of the San Gabriel Mountains, in the NE \ of Section ·33, T4N, RSW, S. B. B. L.
f,M. The proposed dining hall addition for the camp is approximately 800 feet
north of Big Pines llighway and 1,800 feet east of Jackson Lake. The location
of the proposed dining hall addition is shown on the geologic index map on Page
2.
A geologic field investigation of Camp Terecita Pines was conducted on August
24, 1979. In addition, our invesl:igation included review of black and white
aerial photographs, flown in 1928, and color infrared photographs, flown in
1978; review of pertinent geologic literature; and review of significant seismic
data, including recorded, historic earthquakes. No subsurface exploration was
conducted for this study.
The area near the site was covered with a mature growth of pine, fir, and oak
trees at the time of our investigation. Man-made improvements in the camp in
clude the cabins, swimming pool, bathing area, chapel, stage, and dining room;
and the entrance and service road for the camp.
I I I I I I I I I I I I I I I I I I I
-2-
GEOLOGIC INDEX MAP Camp Tcrecita Pines
Big Pines Recreational Area Angeles National Forest
Legend
@ Landslide
Qal Qoa be
ps
---
Younger alluvium Older alluvium
Gary S. Rasmussen & Associates, Inc.
I I I I I I I I I I I I I I ,. I I ,I I
Camp Terecita Pines Dining Hall Addition - Wrightwood August 31, 1979
GEOLOGIC SETTING
Project No. 1551
The camp is situated on the north side of a long ,linear valley of the San Andreas
.rift zone. The proposed dining ha.11 addition to Camp Terecita Pines is located
approxi.mately 800 feet north of the most recent break of the active San Andreas
fault as mapped by Ross (1969) and approximately 50 to 100 feet north of the
Alquist-Pri.olo Special Studies Zone as designated by the California Division of
Mines and Geology (Alquist-Priolo Special Studies Zone Map of the Mescal Creek
quadrangle).
In this general region, the area south of the San Andreas fault is characteristi
cally underlain by white mica, quartz, feldspar, schist, with lesser amounts of
chlorite schist, quartzite, and talc-actinolite rock. North of the San Andreas
fault zone diorite, quartz monzoni te, gneiss and .myloni tic gneiss are the most
common rocks encountered. A thin sliver of the Miocene Punchbowl formation is
mapped along the north side of the San Andreas fault (Noble, 1953) but it was
not encountered during our investigation. Old, inactive faults parallel the San
Andreas fault both north and south of its main trace (Noble, 1953 and Dibblee,
1968a, 1968b, 1970, 1975) in this area,
Large scale landsliding is common within the Pelona Schist, and very Jarge land
slide-mudflows have caused considerable p.roperty loss within the town of Wrightwood,
approximately 8 miles to the southeast. Small-scale landslides are also quite
common in the vicinity, and Camp Mctaka, which is approximately 1,800 feet south
east of the site, :is currently being damaged by a landslide along the east fork
of Mescal Creek. The landslides in the area are caused by high levels of p1·eci-
pi tat:ion and/or seismic shaking affecting areas of high relief (Morton and Campbell,
1978, Kojan, 1979).
SITE GEOLOGY
The proposed dining hall addition for Camp Terecita P:ines lies on a relatively
planar surface which slopes downward to the north, approximately 10 degrees. In
a relatively undisturbed area south of the proposed dining hall addition, the
-3-0-ARY S. RASMUBSE:N' &. ASSOCIATES
I I I I I I I I ·I I I I I I I I I I I
Camp Terecita Pines Dining Hall Addition - Wrightwood August 31, 1979
Project No. 1551
surface clasts include a majority of white mica-quartz-feldspar Pelona Schist,
with lesser amounts of chlorite bearing schist, retrograde Pelona Schist mylonite,
quartzite, diorite, amphiboli te gneiss, and rare quartz monzoni te. The majority
of Pelona Schist clasts have well developed planar foliation, however, a few
clasts were observed which exhibit kink banding. Within the canyon along the
east side of the camp, tabular clasts of the Pclona Schist were observed near
the top portion of the formation where they lie parallel to the ground surface.
Most of the clasts are angular to subangular, however, a minor amount of rounding
has apparently occurred. Based on these observations, we infer that the material
on which the proposed din.i ng hall addition to Camp Tereci ta Pines is to be con
structed is of alluvial and not mud flow orig.in.
The material within the mudflows emanating from Heath Canyon and Sheep Canyon rn
the Wrightwood area is almost exclus.ively composed of Pelona Schist detritus
which is angular, unsorted, and randomly arranged as to orientation of tabular
clasts. The landslide-mudflows in the Wrightwood area are three-stage cyclic
events (Morton & Campbell, 1978). The first stage is large-scale landslidi.ng at
the head of major canyons (Sheep and Heath Canyons). The second stage is smaller
scale landsliding of the first stt•ge landslide mass. The third stage is the mud
flow. Mudflows arc the most destructive and costly to the Wrightwood area of all
three stages of the failures. They occur when the broken up material of the second
phase slides become saturated with water during the spring thaw following periods
of high precipitation, thereby resulting in a cohesionless mass. Although numerous
small -scale landslides were observed on the aerial photographs on the steep slopes
south of Camp Terecita Pines, none were of the scale of the first-cycle landslide
within Heath Canyon and Sheep Canyon. The landslides, as opposed to mudflows,
within the Pelona Schist are generally moved only short distances at low velocities
(Morton and Campbell, 1978). The closest steep sloping mass of Pelona Schist
to the proposed dining hall addition to Camp Tereci ta Pines is located approxi
mately 1,000 feet to the south. Based on the above and on field observations
landsliding does not appear to be a significant hazard to the proposed addition.
One small-scale debris slide was observed on the camp property approximately 600
feet north of the proposed dining hall addition. At this location, the very steep
-4-GARY S. RASMUSSE:N & ASSOCIATES
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Camp Terecita Pines Dining Hall Addition, Wrightwood August 31, 1979
Project No. 1551
north facing stream bank is failing by intermittent shallow debris slides. This
slide, located adjacent to the chapel and stage, will probably some day affect
those two structures. The rate of advance of this slide should be monitored by
camp personnel.
A faint, west-northwest trending l.ineament was observed on aerial photographs
projecting toward the site. This lineament was not observed across the alluvium
under the site, docs not affect the surface grading of the alluvial material, nor
was it observed affecting very old, dissected landslide masses to the southeast
of the site. There is no evidence that the geomorphology of the camp has been
affected by the fault. Field investigation revealed that this lineament is a
fault affecting the bedrock southeast and northwest of the camp. Although no
subsurface investigation was undertaken for this study, the west bank of the
stream, which is incised approximately 30 to 35 feet into both the alluvium on
the west and the bedrock on the east, was examined for fault related features.
Al though much of the bank exposing alluvium was covered with slope wash and
colluvium, no indications of a fault or fault related features were observed
along the projection of the bedrock fault, where it was observed to the south-
east.
No absolute method of dating the alluvium under the site was available for this
study. The alluvium is interpreted as being Pleistocene in age, based on the
following evidence. The closest material south of the San Andreas fault which
has a geomorphic expression similar to that of the older alluvium under the site
is located approximately 2,000 to 3,000 feet to the northwest, within the drainage
on the west side of Jackson Lake. This suggests that the older alluvium has
been offset, in a right-lateral manner a minimum of approximately 2,000 to 3,000
feet since its deposition. Sieh (1978) suggests an offset rate for this portion
of the San Andre"s fault of 3. 7 cm per year based on his investigation of this
porti,on of the San Andreas fault (Sieh, 1971). Using the 3. 7 cm per year offset
rate, the suggested offset equivalents across the San Andreas fault would indicat:e
an age of between 16,SOO years and 24,700 years for the deposition of the alluvium
under Camp Terecita Pines. It is, however, possible that the source of the alluvium
under the site was from a canyon farther to the northwest, which would indicate
-S-O.AR¥ $,RASMUSSEN & ASSOCIATES
I I I I I I I I I I I I I I I I I I I
Camp Terecita Pines Dining Hall Addition, Wrightwood August 31, 1979
Project No. 1551
an even older age for the material. Based on the evidence that the fault in the
bedrock apparently does not offset the alluvial material under the camp, the
old dissected landslides to the southeast of the camp have not been offset by
the fault, and the fault does not exhibit a geomorphic expression through the
older alluvium, it appears that the fault is inactive, presenting minimal hazard
to the site from a surface rupture standpoint. It is remotely possible that during
a major event on the San Andreas fault, approximately 800 feet south of the pro
posed dining hall addition, minor differential settlement or sympathetic movement
could occur along the old fault plane, therefore, we suggest that the addition
be designed to w.ithstand minor tensional cracking.
SEISMIC SETTING
The west-northwest trending San Andreas fault zone, located approximately 800 feet
south of the proposed ·dining hall addition for Camp Terecita Pines, is the most
significant tectonic feature in the area. Other active faults of significance
in the area are the San Jacinto fault and the Cucamonga fault.
Other active faults are located in the general region, hut they are considered less
significant to the site. than the above mentioned faults because of their greater
distance and/or lower probability of having a significant earthquake occur along
them which m:ight affoct the proposed dining hall addition. A summary of the major
faults and their distances from the site is shown in the following table;
FAULT
San Andreas
San Jac.i.nto
Cucamonga
SEISMIC HISTORY
DISTANCE FROM SITE (MILES)
800 feet SSW
6 SE
15 s
The San Andreas, San Jacinto, and Cucamonga fault zones are all considered to be
active faults. The San Andreas fault has been seismically quiet along its south
central reach ln southern Cali fomia in recent times. The last significant earth-
-6-GARY$. RASMUSSEN & ..ASSOCIATES
I I I I I I I I I I I I I I I I I I I
Camp Terecita Pines Dining Ilall Addition, Wrightwood August 31, 1979
Project No. 1551
quake along it was the great Port Tejon earthquake of 1857, centered near Port
Tejon, north of Gorman, which ruptured the ground surface along the fault 800
feet southwest of the dining hall. The San Andreas fault in this area has a
pattern of almost no movement for long periods of time (160± years, Sieh, 1977)
followed by a sudden release of large amounts of energy and related surface
rupture. The Port Tejon earthquake had an estimated Richter magnitude of 8\+
(Sieh, 1978) which is comparable to the 1906 San Francisco earthquake. A minor
earthquake on 28 August, 1979 with a Richter magnitude of 3.5 was centered within
approximately 5 miles of the site. No ground rupture was associated with this
earthquake.
Numerous earthquakes between Richter magnitude 6.0 to 7.0 have occurred along the
length of the San Jacinto fault zone between the San Gabriel Mountains and Mexico
during historic times. Since 1890, an earthquake within this magnitude range
has occurred somewhere along the fault a.t least once every 5 to 6 years (Lamar,
et.al., 1973). Several of these earthquakes were centered in the Lytle Creek
area, approximately 8 miles from the site.
Documented evidence for large earthquakes along the Cucamonga fault has not yet
been found. However, this fault is pat·t of the Sierra Madre-Cucamonga fault
system which did move in the 1971 San Fernando earthquake of Richter magnitude
6.4. A subsurface investigation in progress by the U.S. Geological Survey has
uncovered evidence of Holocene activity along the Cucamonga fault (personal
communication, Morton, Tinsley, and McFadden, .June, 1979).
SEISMIC ANALYSIS
The most signific;mt earthquake affecting the site is likely to occur on the San
Andreas fault during the life of the proposed dining hall addition. Significant
earthquakes affecting the site are also likely to occur on both the San .Jacinto
and Cucamonga faults. A recurrence interval of approximately 160:!: years for
major earthquakes along the Sun Andreas fault is suggested by Sieh (1977) based
on his investigation of sediments along Pallet Creek, approximately 10 miles
northwest of the site. The last significant earthquake along the San Andreas
affecting thi.s site occurred on January 9, 1857. Recurrence intervals for maximum
-7-GARY $. R..ASM'U'SSEN & .ASSOCIAT~S
I I I I I I I I I I I I I I I I I I I
Camp Terecita Pines Dining Hall Addition, Wrightwood August 31, 1979
Project No. 1551
probable earthquakes along the San Jacinto and Cucamonga faults cannot yet be
determined from a statistical standpoint as recorded information on seismic
activity does not encompass a sufficient span of time, and no detailed analyses
of sediments along either of these two faults, sililar to that undertaken at
Pallet Creek by Sioh (1977), have been reported. Based on the information
available at this time, it is our opinion that a probable earthquake of Richter
magnitude S.O+ shot1ld be expected (at least 50 percent chance of occurrence
wi.thi.n the next 100 years) along the San Andreas foul t 800 feet south-southwest
of the proposed dining hall. Larger earthquakes could possibly occur on any
of these foul ts, but their probability of occurrence for that time period is
low. A Richter magnitude 8.0 earthquake along the San Andreas fault zone should
be expected to produce a maximum peak ground acceleration Jn bedrock under the
site of approximately 0.7Sg+ (Schnabel & Seed, 1973). This corresponds to a
maximum repeatab_le bedrock acceleration of 0.49g+ (Ploessel & Slosson, 1974).
These accelerations should not be used as a design value as they are maximum
accelerations in bedrock, estimated to he at least 30 to SO feet beneath the site;
rather, they should be regarded us an aid in the structural evaluation of the
proposed building.
Large earthquakes may occur on other faults in the area, but are considered less
significant to the site because of their greater distance or lower probability
of occurrence than the above.
HYDROLOGY
Streams were observed fl owing in the drainages east, north and west of the site.
These streams are currently flowing approximately 30 feet below the surface of
the alluvium on the site. No springs were observed issuing from the alluvium
within the incised drainages bounding the site. The streams within the drainages
are interpreted as being zones of infiltration of ground water, as opposed to
zones of exfUtration, because of the close proximity of the effective ground
water barrier, the San Andreas fault, above (south of) the site. Ground water
is therefore, probably at least 30 feet beneath the ground surface under the
site.
-8-GARY S. RASMUSSJi;:N &; A$$0Cl.A'I'ES
I I I I I I I I I I I I I I I I I I I
Camp Terecita Pines Dining Hall Addition, Wrightwood August 31, 1979
FLOODING
Project No. 1551
The drainages wh:i ch currently flow east, south and west of the site are somewhat
prone to flooding. However, because of the deep entrenchment of these stream
courses, flood:i ng of the building site is highly unlikely. This is further
substantiated by the occurrence of large (4 to 5-foot diameter) fir trees, esti
mated to be of the order of 300 to 500 years old, growing on terraces, approxi
mately 15 to 20 feet below the surface of the building site. Seismically induced
flooding of the drainage on the west s:i de of the camp is possible as the dam for
Jackson Lake is built directly upon the main, active trace of the San Andreas
fault. Because of the small volume of water within Jackson Lake, and the size
of the incised drainage on the west side of the site, any flooding probably
would not affect the proposed building itself.
CONCLUSIONS
Severe seismic shaking of the proposed dining hall addition can be expected
within the next 100 years. This shaking is expected to be no more severe for
this site than for other sites in the vicini tY.
A photo lineament projecting through the site was observed in the field to be
a bedrock fault, and does not affect the Pleistocene alluvium under the proposed
dining hall. This fault is considered to be inactive, presenting minimal hazard
to the site from a fu.ult rupture standpoint. However, it is possible that sym
pethetic movement or differential settlement could occur along the fault. This
apparently did not occur during the 1857 earthquake.
Because of its position, the proposed building is not prone to being inundated
by landslides or debris flows. A small-scale debris slide is located in the far
northern portion of the site, along the steep stream bank, near the chapel a.nd
the stage.
Liquefaction is not expected to be a problem because of the coarse, poorly sorted
natore of the sediments, their probable Pleistocene age and high density, and
-9-G.ARY $. RASMUSSEN &. ASSOClA'I'ES
I I I I I I I I I I I I I I I I I I I
Camp Terecita Pines Dining Hall, Wrightwood August 31, 1979
Project No. 1551
the estimated minimum depth to ground water of at least 30 feet.
Flooding and se·i smically Jnduccd flooding is not expected to be a hazard to the
building because of the deeply incised drainages on the cast, north and west.
RECOMMENDATIONS
A Richter magnitude 8 .. 0 earthquake is expected along the San A:nd.reas fault zone
(800 feet south-southwest of the proposed dining hall addition); therefore, we
recommend human occupancy structures be designed accordingly.
A slight possibility for syinpethetic movement or d.i fferential settlement along
the older, inactive fault which projects near the building is possible; there-
fore, we suggest this be taken into consideration during the design of the proposed
addition,
Because of the debris slide fai.lure along the northern margin of the camp, we
recommend a minimum setback for human occupancy structures from the top of
slopes above existing incised drainages should be the greater distance calculated
from the following two methods: 1) A 2: 1 (horizontal to vertical) plane,
extending upward from the toe of the steep slopes, If several oversteepened
slopes exist on any one slope, the setback shoul cl be the farthest from the
top of tho slope (see Enclosure l); 2) A horizontal distance equal to J, the
vertical height (distance from tho top edge of the steep slope to bottom of
drainage). The Soils Engineer may impose greater restrictions and recommended
setbacks based on slope stability analysis using actual shear parameters, how
ever, the recommended setback (greater of the two possibilities) is considered
to be a minimum from a geologic st<>ndpoint.
Much of Camp Tcrcci ta Pines south of the proposed dining hall add:i tion lies
within an A:lqui st-Priolo Special Studies Zone as illustrated on the index map
on page 2; therefore, we recommend that no human occupancy structures be planned
for that portion of the site unless a detailed subsurface investigation is under
taken by an engineering geologist in accordance with the Alquist-Priolo Special
-10-GARY $. R.A$:t.!!t,;T$SEN & A$$0C.t.ATE$
I I I I I I I I I I I I I I I I I I I
camp Terecita Pines Dining Hall Addition, Wrightwood August 31, 1979
Studios Zones Act.
Project No. 1551
Please feel free to contact us if you have any questions regarding this report.
TES:GSR/rc
Respectfully submitted,
GARY S. RASMUSSEN & ASSOCIATES
~c.S~ Thomas E. Spittler Staff Geologist
Gary S. Rasmussen Engineering Geologist, EG 925
Enclosures; 1: Slope Setback Illustration 2: References
Distribution: John Fortune and Associates (5) Tcrecita Pines, Inc. (1)
-11-GARY$. E.1\.SWUSSEN &. ASSOCIATES
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------
Slope Setback Illustrations
ground surface~
ground surf;lcc-......._
2;1
f'NCLOSlJRE l
J1.iini1num rcconuncnded set buck
GARY S. R~SMUSSEN & ASSOCIATES, INC. Project No. 1551
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REFERENCES
Allen, C.R., Saint Amand, P., Richter, C.F., and Nordquist, J.M., 1965, Relationship between seismicity and geologic structure in the southern California region: Seismological Society of America Bulletin, V. 55, No. 4, p. 753-797.
Bennett, .J.H., and Rodgers, P.A., 1975, Crustal Movement Investigations along the San Andreas fault in southern California, in COMG Special Report 118, p. 53-60.
Bolt, B. A., 1970, Causes of earthquakes, Earthquake Engineering, Prenticellall, Englewood Cliffs, Ch. 3, pp. 21-47.-
Bonilla, M.G., 1970, Surface fault.ing and related effects in earthquake engineering, .!Jarthqmike l!ngin.cering, Prentice-Hall, Englewood Cliffs, Ch. 3, pp 47-74.
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