New Info on the Origin of Bimodal Volcanism on Oregon’s High Lava Plains

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New Info on the Origin of Bimodal Volcanism on Oregon’s High Lava Plains

April’s Friday night lecture was given by a truly distinguished Oregon geologist and highlighted recent research into an area that has long intrigued geoscientists about Oregon. Dr. Anita Grunder has led a team of researchers, including PSU’s Martin Streck, exploring the possible origin of the magma that has peppered Oregon’s High Lava Plains geologic province in the last 12 million years. This magma includes both rhyolite and basalt eruptions in a swath of territory between Steen’s Mountain region to the southeast and Newberry Volcano to the northwest. 

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Speaker Mike Collins Provides Dramatic Visualizations of Hotspot Evolution

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Speaker Mike Collins Provides Dramatic Visualizations of Hotspot Evolution

Mike Collins, a retired administrator in manufacturing, and an avid mountaineering and geology enthusiast, presented his slide show “Flood Basalts, Hot Spots, and Spreading Centers and the Creation of the Western Landscape,” to a full house last month at the GSOC Friday night lecture. His show was based upon a manuscript he has produced explaining the evolution of the Western landscape in terms that non-technical people can understand. It is lavishly illustrated with scratchboard drawings that he has drawn, which take the reader back to scenes he describes in the book. 

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Rhyolites, CRBs & the Yellowstone Hot Spot — Research by Dr. Martin Streck

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Rhyolites, CRBs & the Yellowstone Hot Spot — Research by Dr. Martin Streck

Martin Streck spoke to a standing room only GSOC crowd about the work that he and a number of his graduate students have done in advancing our knowledge of the Columbia River Basalt (CRB) flows of the Miocene. His team has focused upon the rhyolite flows that occurred as a result of heating by the basalt magma that produced the CRB.

Miocene rhyolite flows in eastern Oregon have long been studied by geologists. The relationship between the rhyolitic magma and the massive amounts of CRB basaltic magma is not precisely known, although they are spatially close so infer that the rhyolite is a result either of partial melting of the crust by or fractional crystallization of the CRB magma. In fact, the spatial distribution over time of the rhyolite can give geologists ideas about the origin of the CRB magma itself.

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