Volcanoes to Vineyards: Geologic Field Trips through the Dynamic Landscape of the Pacific Northwest

This volume contains guides for 33 geological field trips offered in conjunction with the October 2009 GSA Annual Meeting in Portland, Oregon. Showcasing the region’s geological diversity, the peer-reviewed papers included here span topics ranging from accreted terrains and mantle plumes to volcanoes, floods, and vineyard terroir. Locations visited throughout Oregon, Washington, and Idaho encompass Astoria to Zillah. More than just a series of maps, the accompanying descriptions, observations, and conclusions offer new insights to the geologic processes and history of the Pacific Northwest insights that will inspire readers to put their boots on the evidence (or perhaps sip it from a glass of Pinot!) as they develop their own understanding of this remarkable and dynamic corner of the world.
Ice and water on Newberry Volcano, central Oregon
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Published:January 01, 2009
ABSTRACT
Newberry Volcano in central Oregon is dry over much of its vast area, except for the lakes in the caldera and the single creek that drains them. Despite the lack of obvious glacial striations and well-formed glacial moraines, evidence indicates that Newberry was glaciated. Meter-sized foreign blocks, commonly with smoothed shapes, are found on cinder cones as far as 7 km from the caldera rim. These cones also show evidence of shaping by flowing ice. In addition, multiple dry channels likely cut by glacial meltwater are common features of the eastern and western flanks of the volcano. On the older eastern flank of the volcano, a complex depositional and erosional history is recorded by lava flows, some of which flowed down channels, and interbedded sediments of probable glacial origin. Postglacial lava flows have subsequently filled some of the channels cut into the sediments. The evidence suggests that Newberry Volcano has been subjected to multiple glaciations.