Named for ophitic clinopyroxene basalt exposed at type locality near Tims Peak, SE/4 sec.34 T21S R40E, Malheur Co, OR. Forms prominent plateau in northern part of Monument Peak district; also occurs in Malheur Gorge district. Thickness is 10 to 250 ft as one or several flow units. Overlies Butte Creek Volcanic Sandstone (new); underlies Wildcat Creek Welded Ash-Flow Tuff (new) or Junction Formation. Correlation chart shows age to be Pliocene (Clarendonian).
Source: GNU records (USGS DDS-6; Menlo GNULEX).
Mapped in northeast corner of Burns 1x2 deg quad, OR. Is medium- to dark-gray, fine-grained and diktytaxitic basalt. Maximum thickness is 400 ft. Overlies Hunter Creek Basalt. Age is Miocene and Pliocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
(advance copy). Unit is geographically extended into report area (Jonesboro 7.5-min quadrangle, Malheur County, Oregon). Age is (middle) Miocene based on radiometric age data (12.4 Ma) and regional stratigraphic relations.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
(advance copy). Unit is extended into report area (South Mountain 7.5-min quadrangle, Malheur Co., OR). Age is middle Miocene.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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