Sediment underthrusting within a continental magmatic arc: Coast Mountains batholith, British Columbia
Name:
Pearson_et_al-2017-Tectonics.pdf
Size:
6.755Mb
Format:
PDF
Description:
Final Published Version
Publisher
AMER GEOPHYSICAL UNIONCitation
Sediment underthrusting within a continental magmatic arc: Coast Mountains batholith, British Columbia 2017, 36 (10):2022 TectonicsJournal
TectonicsRights
©2017. American Geophysical Union. All Rights Reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Though continental magmatic arcs are factories for new continental crust, a significant proportion of continental arc magmas are recycled from supracrustal material. To evaluate the relative contributions of retroarc underthrusting and trench side partial sediment subduction for introducing supracrustal rocks to the middle and lower crust of continental magmatic arcs, we present results from the deeply exposed country rocks of the Coast Mountains batholith of western British Columbia. Prior work demonstrates that these rocks underwent widespread partial melting that contributed to the Coast Mountains batholith. We utilize U-Pb zircon geochronology, Sm-Nd thermochronology, and field-based studies to document the protoliths and early burial history of amphibolite and granulite-facies metasedimentary rocks in the Central Gneiss Complex. U-Pb detrital zircon data from the structurally highest sample localities yielded similar to 190Ma unimodal age peaks and suggest that retroarc rocks of the Stikine terrane constitute a substantial portion of the Central Gneiss Complex. These supracrustal rocks underwent thrust-related burial and metamorphism at >25km depths prior to similar to 80Ma. These rocks may also be underlain at the deepest exposed structural levels by Upper Cretaceous metasedimentary rocks, which may have been emplaced as a result of trench side underplating or intraarc burial. These results further our understanding of the mechanisms of material transport within the continental lithosphere along Cordilleran subduction margins.Note
6 month embargo; Published online:16 OCT 2017ISSN
02787407Version
Final published versionSponsors
NSF [EAR-0309885, EAR-1338583]; Idaho State University; Romanian National Science funding agency UEFISCDI grant [PN-III-P4-ID-PCE-2016-0127]Additional Links
http://doi.wiley.com/10.1002/2017TC004594ae974a485f413a2113503eed53cd6c53
10.1002/2017TC004594