Record Details
Eocene extension in Idaho generated massive sediment floods into the Franciscan trench and into the Tyee, Great Valley, and Green River basins
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Eocene extension in Idaho generated massive sediment floods into the Franciscan trench and into the Tyee, Great Valley, and Green River basins |
| Names |
Dumitru, Trevor A.
(creator) Ernst, W.G. (creator) Wright, James E. (creator) Wooden, Joseph L. (creator) Wells, Ray E. (creator) Farmer, Lucia P. (creator) Kent, Adam J.R. (creator) Graham, Stephan A. (creator) |
| Date Issued | 2012-11-06 (iso8601) |
| Note | To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Geological Society of America and can be found at: http://www.geosociety.org/. |
| Abstract | The Franciscan Complex accretionary prism was assembled during an similar to 165-m.y.-long period of subduction of Pacific Ocean plates beneath the western margin of the North American plate. In such fossil subduction complexes, it is generally difficult to reconstruct details of the accretion of continent-derived sediments and to evaluate the factors that controlled accretion. New detrital zircon U-Pb ages indicate that much of the major Coastal belt subunit of the Franciscan Complex represents a massive, relatively brief, surge of near-trench deposition and accretion during Eocene time (ca. 53-49 Ma). Sediments were sourced mainly from the distant Idaho Batholith region rather than the nearby Sierra Nevada. Idaho detritus also fed the Great Valley forearc basin of California (ca. 53-37 Ma), the Tyee forearc basin of coastal Oregon (49 to ca. 36 Ma), and the greater Green River lake basin of Wyoming (50-47 Ma). Plutonism in the Idaho Batholith spanned 98-53 Ma in a contractional setting; it was abruptly superseded by major extension in the Bitterroot, Anaconda, Clearwater, and Priest River metamorphic core complexes (53-40 Ma) and by major volcanism in the Challis volcanic field (51-43 Ma). This extensional tectonism apparently deformed and uplifted a broad region, shedding voluminous sediments toward depocenters to the west and southeast. In the Franciscan Coastal belt, the major increase in sediment input apparently triggered a pulse of massive accretion, a pulse ultimately controlled by continental tectonism far within the interior of the North American plate, rather than by some tectonic event along the plate boundary itself. |
| Genre | Article |
| Topic | Oregon Coast Range |
| Identifier | Trevor A Dumitru, WG Ernst, James E Wright, Joseph L Wooden, Ray E Wells, Lucia P Farmer, . . . Stephan A Graham. (2013). Eocene extension in idaho generated massive sediment floods into the franciscan trench and into the tyee, great valley, and green river basins. Geology, 41(2), 187. doi:10.1130/G33746.1 |
