Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and
Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt;...
Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and
Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt;...
Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and
Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt;...
Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and
Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt;...
The Coyote Hills are located about 46 kilometers north-northwest
of Lakeview, Oregon, within the Basin and Range physiographic province.
These hills represent a complex volcanic center of bimodal
calc-alkaline igneous activity.
The oldest rocks recorded in the Tertiary succession are horn-blende-
bearing andesite and aphanitic basalt flows, laharic breccias,
conglomerates,...
Full Text:
Mineral Deposits of the
Coyote Hills Mining District, Lake County, Oregon
by
Thomas Holbeck Thomas
A
One important cool-season perennial grass seed crop grown in Oregon is fine fescue (Festuca rubra L.). Open-field burning has been used for many decades to manage pests, cycle nutrients, and stabilize yield, in fine fescue seed fields, especially as stands age. Legislative restrictions currently limit open-field burning to 6,070 hectares...
The northwest-trending Neogene Tualatin basin in northwestern Oregon is a pull-apart
basin with approximately 750 m of post-middle Miocene structural relief. Gently
tilted uplands capped by Columbia River Basalt Group surround the synclinal basin on all
sides. Integrated gravity, aeromagnetic, and seismic reflection data indicated that the
basin is underlain...
The northwest-trending Neogene Tualatin basin in northwestern Oregon is a pull-apart
basin with approximately 750 m of post-middle Miocene structural relief. Gently
tilted uplands capped by Columbia River Basalt Group surround the synclinal basin on all
sides. Integrated gravity, aeromagnetic, and seismic reflection data indicated that the
basin is underlain...
The northwest-trending Neogene Tualatin basin in northwestern Oregon is a pull-apart
basin with approximately 750 m of post-middle Miocene structural relief. Gently
tilted uplands capped by Columbia River Basalt Group surround the synclinal basin on all
sides. Integrated gravity, aeromagnetic, and seismic reflection data indicated that the
basin is underlain...
The northwest-trending Neogene Tualatin basin in northwestern Oregon is a pull-apart
basin with approximately 750 m of post-middle Miocene structural relief. Gently
tilted uplands capped by Columbia River Basalt Group surround the synclinal basin on all
sides. Integrated gravity, aeromagnetic, and seismic reflection data indicated that the
basin is underlain...