Record Details

Geology and structure of the Brothers Fault Zone in the central part of the Millican SE quadrangle, Deschutes County, Oregon

ScholarsArchive at Oregon State University

Field Value
Title Geology and structure of the Brothers Fault Zone in the central part of the Millican SE quadrangle, Deschutes County, Oregon
Names Tucker, Elizabeth Ruth (creator)
Lawrence, Robert (advisor)
Date Issued 1975-08-14 (iso8601)
Note Graduation date: 1976
Abstract The thesis is a structural and petrographic study of approximately
23 square miles in the Millican SE quadrangle, Deschutes
County, Oregon. The area lies along the Brothers fault zone.
Bedrock in the area is of Pliocene to Recent age and consists
of an older basaltic unit with an associated dacite, a younger dacite,
and a younger basaltic unit. The older basaltic unit and both dacites
have been severely faulted. The younger basaltic unit has filled in
topographic lows and is relatively undeformed.
The dominant faults in the area are en echelon high-angle
normal faults trending N. 40°W. with vertical displacements up to
600 feet. Cross faults with smaller displacements trend N. 45°E.
The normal faults are Reidel and conjugate Reidel shears and are
interpreted as the surface expression of a deep-seated right lateral
displacement. The fault zone displaces units of Miocene to Pleistocene
age and is considered to have been active during that time.
Genre Thesis/Dissertation
Topic Geology -- Oregon -- Brothers Fault Zone
Identifier http://hdl.handle.net/1957/45824

© Western Waters Digital Library - GWLA member projects - Designed by the J. Willard Marriott Library - Hosted by Oregon State University Libraries and Press