The effects of pH and time on the formation of hydroxy-Al, Fe,
and Mg interlayer were compared for montmorillonite and vermiculite.
The stability of interlayers was evaluated by sequentially increasing
the severity of dissolution treatments and by subjecting the inter-layers to an HC1 treatment. The interlayer formation and stability
were...
Soils developed on volcanic ash exhibit several unique properties
not commonly observed in soils formed on other geologic
material. Low thermal conductivities, low volumetric heat capacities,
slow transport phenomena, excess macro-drainage and
development of unique suites of clay minerals are some properties
thought to be directly related to the vesicular...
A study was conducted to determine the mineralogy and chemical
properties of "Ando-like" western Oregon soils. The samples
were collected from 13 sites which formed mainly from basaltic
rocks, a contact metamorphic rock, sedimentary rocks, and
alluvium derived from sedimentary rock and from volcanic rock. All
samples contained small amounts...
Previous studies of pumiceous soils in Oregon indicated that
their physical and chemical properties were strongly related to the
porous nature of the pumice matrix. Soils developed on air-fall
pumice from the eruption of Mt. Mazama (Crater Lake, Oregon) had
low thermal conductivities and low volumetric heat capacities. Values
for...
Soil samples from the Mazama tephra deposit were collected
from the AC and C2 horizons at five different locations along the axis
of the main depositional lobe. The clay fraction from the samples
was recovered and studied by means of chemical, x-ray, DTA and
electron microscopy methods in order to...
Investigations were conducted to (1) determine the original
pattern of deposition and thickness of ash in the Ochoco and Blue
Mountain areas of Oregon, (2) determine if discontinuities exist in
the parent material of these soils, (3) determine the degree of mixing
of ash with other materials and evaluate reworking...