The Washougal Mining District is approximately 50 km (30
miles) northeast of Vancouver, Washington, along the western
slopes of the Cascade Range. Although the district has produced
the unostentatious amount of $572 in metals since 1903, the presence
of porphyritic intrusions, hydrothermal alteration, breccia pipes,
and base-metal mineralization typical of...
Timber management of coastal watersheds in southwest Oregon has
been complicated by the need to protect anadromous fish habitat from
accelerated stream sedimentation resulting from management activity.
The rugged terrain of the Elk and Sixes River basins is underlain by
the complex geological province of the Klamath Mountains, in which...
HARNEY COUNTY HISTORY PROJECT
AV-Oral History #469
Interviewee: Eileen O'Keeffe McVicker
Interviewer: Karen Nitz
Subject: Homesteading on the South End of Steens Mountain
Date: October 16, 2008
Place: Chester & Helen Felt Recording Room, Harney County Library, Burns, Oregon
The middle Eocene Tillamook Volcanics form the oldest rock unit in the Elsie-lower Nehalem River area. K-Ar age determinations and age constraints imposed by foraminiferal and calcareous nannofossil assemblages of overlying sedimentary strata indicate an absolute age of about 42 Ma for the uppermost Tillamook Volcanics. Major oxide values indicate...
Speckled dace (Rhinichthys osculus) is a small cyprinid that is geographically widespread throughout western North America, and the most frequently occurring sh in Oregon. Because of the genetic and morphological variation in this species across its range, it has been referred to as a "species complex" and no revision to...
Five distinct lithologic units compose the Tertiary rocks in the Tillamook Head - Necanicum Junction area of the northern Oregon Coast Range. They are: the late Eocene to early Miocene Oswald West mudstones, the middle Miocene Angora Peak sandstone and
Silver Point mudstone members of the Astoria Formation, and the...
Surface and subsurface data are combined to determine the structure of the western half of the Simi fault system in the Las Posas and Camarillo Hills area. Cretaceous to Eocene sedimentary rocks, present only in the subsurface, are overlain by late Eocene to early Miocene nonmarine stata (Sespe Formation) and...