Landscape Evolution at an Active Plate Margin - Biological Science ...

end in a dextral shear system that extends from the
Indian Wells Valley northward into the Owens Valley.
This results in northwest-directed transtension, which
is accommodated by normal and strike-slip faulting.
This necessitates that the Owens Valley fault must
extend southward from Diaz Lake in the Alabama
Hills, beneath the sediments of Owens Lake, to the
eastern side of the Coso Range where it steps west to
the Little Lake fault. If so, the tectonic setting would
be analogous to southern Death Valley, where basalts
have been emplaced along the Black Mountain
detachment formed by a right step in the Furnace
Creek-Southern Death Valley fault zone.
Return to the vehicles and Hwy 395, bearing left at
the cattle guard.
101.3 (0.2) Stop at pavement, watch for cross traffic.
TURN LEFT (north) on Hwy 395.
101.5 (0.2) Little Lake on the right is a spring-fed lake
augmented by a low dam.
101.9 (0.4) Continue past the turnoff to Little Lake
Ranch (private duck hunting club) to the right. Red
Hill (the scoria cone just north of the turnoff) is
straight ahead. Red Hill is one of the youngest volcanic
features in the Coso volcanic field. It is thought to
be no older than 10,000 B.P. and may have last experienced
a flank eruption within the last 1000 years. The
flank eruption is marked by a small crater that lies
on the northwest side of the cinder cone and is best
seen traveling south on Hwy 395. CEMEX currently
operates the Red Hill Quarry on the south flank of
the cinder cone. They have a small crusher plant that
produces a fine scoria aggregate used for road cinders
and in the manufacture of cinder block, as well as
larger-sized material utilized for landscaping.
104.6 (2.7) Continue past a right (east) turn at Cinder
Road to Fossil Falls BLM campground. Continue
north on Hwy 395. The Fossil Falls campground and
interpretive nature walk lie a short distance along this
road. Fossil Falls gets its name from the basalt outcrop
that marked an active waterfall or rapids in the
Owens River during times of a wetter climate. The last
major overflow of water from the Owens River into
China and Searles Lakes probably occurred about
4,000 years ago (Bates, this volume). The potholes in
the basalt attest to the water’s velocity. The basalt here
is typical of the Little Lake Basalt, with prominent
olivine phenocrysts.
109.4 (4.8) Coso Junction Rest Stop. Trees and greenery
to the west at 9:00 mark the trace of the SNFF.
D. R. Jessey and R. E. Reynolds
Three lines to the west are: upper, old LADWP aqueduct
(1913); center, Southern Pacific railroad to Lone
Pine; lower, new LADWP aqueduct (1967).
112.3 (2.9) Northeast at 1:30 you can see an ancient
landslide that blocked the drainage of the Owens
River. The river subsequently cut through the toe of
the slide and resumed its normal channel.
112.4 (0.1) Dunmovin.
112.9 (0.5) Continue past a right turn to the Haiwee
Power Plant.
116.2 (3.3) Continue past a right turn on Haiwee
Road leading to the reservoir. Haiwee Reservoir,
to the east, marks the southernmost “lake” in the
LADWP system for the eastern Sierra. Two intakes,
one constructed in 1913 and the second in 1970, draw
water from the reservoir. From this point southward
to Los Angeles, the Owens River flows only in aqueducts.
The high peak on the Sierra crest at 10:00 is
Olancha Peak (el. 12,122 ft).
117.1 (0.9) Haiwee Canyon Road is on the left.
119.2 (2.1) Continue past Lakeview Road. Vegetation
marks the SNFF scarp (west).
120.9 (1.7) Sage Flat Road junction. Continue on
Hwy 395.
122.1 (1.2) North Haiwee Road crosses spurs of the
S. P. railroad that served during construction of the
LADWP aqueduct.
122.8 (0.7) Cross the LADWP aqueduct.
124.1 (1.3) Continue past a right turn to Cactus Flat.
124.5 (0.4) Continue past a left turn to Walker Creek
Road and a wild burro refuge.
125.5 (1.0) The historical marker commemorates the
Farley Olancha mill site. Look east to the Plio-Pleistocene
basalt of the Darwin volcanic field that drapes
the south end of the Inyo Mountains. The basalt covers
Paleozoic sedimentary rocks and metamorphosed
Mesozoic volcanics and sediments.
126.0 (0.5) Continue past the junction with CA 190
and continue north on Hwy 395 toward Lone Pine.
CA 190 heads east across the Darwin Plateau and
Panamint Valley before descending into Death Valley.
127.5 (1.5) The Crystal Geyser bottled water plant
is on the right. This plant began producing bottled
water in 1990. Since then, two additional plants have
16 2009 Desert Symposium