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The Portland Basin: A (big) river runs through it

January 1, 2009

Metropolitan Portland, Oregon, USA, lies within a small Neogene to Holocene basin in the forearc of the Cascadia subduction system. Although the basin owes its existence and structural development to its convergent-margin tectonic setting, the stratigraphic architecture of basin-fill deposits chiefly reflects its physiographic position along the lower reaches of the continental-scale Columbia River system. As a result of this globally unique setting, the basin preserves a complex record of aggradation and incision in response to distant as well as local tectonic, volcanic, and climatic events. Voluminous flood basalts, continental and locally derived sediment and volcanic debris, and catastrophic flood deposits all accumulated in an area influenced by contemporaneous tectonic deformation and variations in regional and local base level.

Publication Year 2009
Title The Portland Basin: A (big) river runs through it
Authors Russell C. Evarts, Jim E. O'Connor, Ray E. Wells, Ian P. Madin
Publication Type Article
Publication Subtype Journal Article
Series Title GSA Today
Index ID 70003358
Record Source USGS Publications Warehouse
USGS Organization Geology and Geophysics Science Center; Oregon Water Science Center