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Figure 2. Panoramic view of one end of the U. S. Army Corps of Engineers Applegate Dam project, in which sand
and gravel, Oregon's major mineral commodity, is being utilized as fill. When completed, the dam will be 242 ft high
and 1,200ft long and will contain 3 million cubic yards of fill. The tall concrete structure on the left is the intake tower
for the dam. The downstream side of the dam is to the right.
The dark strip in the center of the photograph is the impervious clay core that is being compacted. The core
extends into a notch cut in the bed rock, thereby keying the entire dam into bed rock. Lighter areas on both sides of
'he core are composed of crushed gravel. The outer layer of the dam will be made of coarser material.
Major mineral commodities being used in the dam are clay, cement, and sand and gravel. As (he sand and gravel
is processed for use as concrete aggregate and fill, the gold content is also recovered. By the end of 1979, $285,000 of
gold had been recovered. (Composite photo courtesy U.S. Army Corps of Engineers)
INDUSTRIAL MINERALS
Sand and gravel and stone accounted for 62 percent
of the total value of Oregon's 1979 mineral products
(Figure 2), as compared with 65 percent in 1978. A
major tightening of the rock-material resource supply
for the Portland area occurred when the Portland
Development Commission purchased the Rivergate
Rock Products Company quarry (point 4) for $3.65
million. Because the quarry operation would have conflicted
with that of a new silicon wafer plant nearby,
drilling.and blasting were stopped at the end of October.
All equipment and stockpiles of crushed stone are to be
removed by May 1980.
Deposits of sand and gravel and stone are nonrenewable
and are rapidly being depleted or removed
from minin'g by urbanization. As the demand increases
and su pply shrinks, the price will inevitably rise. Careful
planning, however, will extend the useful life of the
deposits. The Department continued its rock-material
program to help such planning by publishing Special
Paper 5, Analysis and Forecasts of the Demand for
Rock Materials in Oregon, by Friedman and others
(1979). The paper provides forecasts for the State and
several substate areas and for the commodities of sand
and gravel and stone. The study also gives forecasting
methodologies that can be used by the planner at the
local level.
Diatomite, composed of the siliceous skeletons of
microscopic aquatic plants called diatoms, was mined,
processed, and sold for pet litter, fertilizer filler, insecticide
carrier, and floor sweep absorbent by American
Fossil, Inc., at its diatomite operation (point 5) in
Christmas Valley, Lake County. During 1979, the
operation was sold to Oil-Dri West, who obtained industrial
revenue bond financing totaling $1.5 million
from the Oregon Economic Development Council for
the purchase and expansion of the operation.
The Oregon Portland Cement Company completed
construction of its new cement plant (point 6) near
Durkee, Baker County. Test runs began in early
November. The new plant, with a capacity of about
500,000 tons of cement per year, is twice as large as the
one it replaced at Lime. Limestone for the plant comes
from a nearby quarry.
Blue Mountain Lime Company purchased the limestone
deposits and a treatment plant formerly owned by
Chemical Lime Company. The plant is located about
5 mi north of Baker, in Baker County, and the
limestone deposits (point 7) are in the Elkhorn Mountains
about 10 mi to the west. The Chemical Lime Company
operated fairly continuously between 1958 and
1970, producing chemical-grade lime and lime products
for the metallurgical and construction industries. The
Blue Mountain Lime Company now has developed
small markets for ground limestone for agricultural purposes,
such as soil additives and feed supplements. It is
utilizing high-quality limestone which, because it was
undersize (minus ~ in.), was stockpiled during the
Chemical Lime Company operation. Equipment for
OREGON GEOLOGY, VOL. 42, NO.3, MARCH 1980
45