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

D. R. Jessey and R. E. Reynolds
Figure 3-8. Salt tram; foundations in foreground; pylon on horizon. [R. E. Reynolds photo]
to the Cottonwood kilns to get more charcoal. When
the Molly Stevens burned, the Bessy Brady steam
paddle-wheeler continued running silver ingots from
Keeler and Swansea to Cartago (Day 1, MP-127.7).
The smelter produced silver ingots faster than Remi
Nedeau’s nine mule teams could carry them on the
route to Mojave. By 1873, over 30,000 ingots were
stockpiled. Enterprising miners stacked the ingots,
stretched canvas over them, and lived in shelters
made of silver bars (Millspaugh, 1971). PROCEED
SOUTH toward Keeler.
81.6 (1.5) PULL RIGHT and PARK at Owens Lake
Desiccation Monument.
STOP 3-8. Owens Lake to the south has been the
southern terminus for the Owens River for the last
800,000 years (Smith et al., 1993). Owens Lake surface
water has been claimed and diverted for human
use. Ground water is now tapped for the water supply.
Arid-land surfaces that were previously stabilized by
vegetation are increasingly susceptible to wind erosion,
causing deflation and dust storms. Since desiccation,
wind-blown dust and salt have created visibility
problems for residents of Owens Valley and military
research at China Lake in Indian Wells Valley (Reheis,
in press).
During the early 1900s the lake fluctuated
between about 20–45 feet deep and had an
area of about 174 sq miles (280 km 2) . Water
was first diverted from the Owens River
to the City of Los Angeles in 1913, and by
1926 Owens Lake was dry.
The dry bed of Owens Lake
has produced enormous
amounts of windblown dust
since the desiccation of the
lake. The lake bed is probably
the largest single source
of dust (aerosol particles
smaller than 10 microns)
in the United States, by one
estimate, 900,000–8,000,000
metric tons per year (Gill
and Gillette, 1991). Assuming
a lake-bed area of 280
km 2 and a density of 1.5-2.0
g/cm 3 for lake sediment,
erosion of this amount of
dust would lower the lake
bed by 0.2-–1.5 centimeters
per year. Micron-size dust
is regulated by California
and United States agencies because dust
particles are so small they can be inhaled
into the human respiratory system to create
health hazards. “One day [in 1995] in
Keeler, particles surged to a nationwide
record that was 23 times greater than
a federal health standard allows” (Los
Angeles Times, 12/17/96). Keeler residents
are exposed to unhealthful levels 25 days
a year. That situation occurs in Ridgecrest
10 days a year (Great Basin air agency).
“When we see the white cloud headed
through the pass, the ER and doctors’ offices
fill up with people. It’s straightforward
cause and effect” (Dr. Bruce Parker, physician
at Ridgecrest Community Hospital).
An additional health concern is inhalation
of trace metals in dust from the lake bed
Table 3-2. Fossil faunas, Owens Lake playa.
Common Name Generic Name
Bony fish Osteichthyes
Minnow Siphateles bicolor snyderi (Miller)
Owens sucker Catostomus fumeiventris Miller*
Lesser scaup Athya affinis
Meadowlark Sturnella neglecta
Botta’s gopher Thomomys bottae
Wolf Canis lupus**
Lion (medium-size) Felidae
Antelope Antilocapra sp. **
Horse Equus sp.
Large camel Camelops sp.
Bison Bison sp.
Elephant Proboscidea
(* Gerald R. Smith, p. c. to Reynolds, 3/09;
** R. Serrano, C. Shaw, p. c. to Reynolds, 3/09)
50 2009 Desert Symposium