CaltechAUTHORS
  A Caltech Library Service

Bulk arc strain, crustal thickening, magma emplacement, and mass balances in the Mesozoic Sierra Nevada arc

Cao, Wenrong and Paterson, Scott and Saleeby, Jason and Zalunardo, Sean (2016) Bulk arc strain, crustal thickening, magma emplacement, and mass balances in the Mesozoic Sierra Nevada arc. Journal of Structural Geology, 84 . pp. 14-30. ISSN 0191-8141. http://resolver.caltech.edu/CaltechAUTHORS:20160422-140516408

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20160422-140516408

Abstract

Quantifying crustal deformation is important for evaluating mass balance, material transfer, and the interplay between tectonism and magmatism in continental arcs. We present a dataset of >650 finite strain analyses compiled from published works and our own studies with associated structural, geochronologic, and geobarometric information in central and southern Sierra Nevada, California, to quantify the arc crust deformation. Our results show that Mesozoic tectonism results in 65% arc-perpendicular bulk crust shortening under a more or less plane strain condition. Mesozoic arc magmatism replaced ∼80% of this actively deforming arc crust with plutons requiring significantly greater crustal thickening. We suggest that by ∼85 Ma, the arc crust thickness was ∼80 km with a 30-km-thick arc root, resulting in a ∼5 km elevation. Most tectonic shortening and magma emplacement must be accommodated by downward displacements of crustal materials into growing crustal roots at the estimated downward transfer rate of 2–13 km/Myr. The downward transfer of crustal materials must occur in active magma channels, or in “escape channels” in between solidified plutons that decrease in size with time and depth resulting in an increase in the intensity of constrictional strain with depth. We argue that both tectonism and magmatism control the thickness of the crust and surface elevation with slight modification by surface erosion. The downward transported crustal materials initially fertilize the MASH zone thus enhancing to the generation of additional magmas. As the crustal root grows it may potentially pinch out and cool the mantle wedge and thus cause reduction of arc magmatism.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/j.jsg.2015.11.002DOIArticle
http://www.sciencedirect.com/science/article/pii/S019181411530047XPublisherArticle
Additional Information:© 2016 Elsevier Ltd. Received 15 June 2015, Revised 29 October 2015, Accepted 3 November 2015, Available online 15 January 2016.
Subject Keywords:Finite strain; Crustal thickening; Magma emplacement; Mass balance; Mesozoic Sierra Nevada arc
Record Number:CaltechAUTHORS:20160422-140516408
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160422-140516408
Official Citation:Wenrong Cao, Scott Paterson, Jason Saleeby, Sean Zalunardo, Bulk arc strain, crustal thickening, magma emplacement, and mass balances in the Mesozoic Sierra Nevada arc, Journal of Structural Geology, Volume 84, March 2016, Pages 14-30, ISSN 0191-8141, http://dx.doi.org/10.1016/j.jsg.2015.11.002. (http://www.sciencedirect.com/science/article/pii/S019181411530047X)
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:66420
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:22 Apr 2016 21:08
Last Modified:22 Apr 2016 21:08

Repository Staff Only: item control page