Arc-continent collision and orocline formation: closing of the Central American seaway

Montes, Camilo, Bayona, G., Cardona, A., Buchs, David ORCID: https://orcid.org/0000-0001-8866-8125, Silva, C. A., Morón, S., Hoyos, N., Ramírez, D. A., Jaramillo, C. A. and Valencia, V. 2012. Arc-continent collision and orocline formation: closing of the Central American seaway. Journal of Geophysical Research: Solid Earth 117 (B4) , B04105. 10.1029/2011JB008959

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Abstract

Closure of the Central American seaway was a local tectonic event with potentially global biotic and environmental repercussions. We report geochronological (six U/Pb LA-ICP-MS zircon ages) and geochemical (19 XRF and ICP-MS analyses) data from the Isthmus of Panama that allow definition of a distinctive succession of plateau sequences to subduction-related protoarc to arc volcaniclastic rocks intruded by Late Cretaceous to middle Eocene intermediate plutonic rocks (67.6 ± 1.4 Ma to 41.1 ± 0.7 Ma). Paleomagnetic analyses (24 sites, 192 cores) in this same belt reveal large counterclockwise vertical-axis rotations (70.9° ± 6.7°), and moderate clockwise rotations (between 40° ± 4.1° and 56.2° ± 11.1°) on either side of an east-west trending fault at the apex of the Isthmus (Rio Gatun Fault), consistent with Isthmus curvature. An Oligocene-Miocene arc crosscuts the older, deformed and segmented arc sequences, and shows no significant vertical-axis rotation or deformation. There are three main stages of deformation: 1) left-lateral, strike-slip offset of the arc (∼100 km), and counterclockwise vertical-axis rotation of western arc segments between 38 and 28 Ma; 2) clockwise rotation of central arc segments between 28 and 25 Ma; and 3) orocline tightening after 25 Ma. When this reconstruction is placed in a global plate tectonic framework, and published exhumation data is added, the Central American seaway disappears at 15 Ma, suggesting that by the time of northern hemisphere glaciation, deep-water circulation had long been severed in Central America.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Earth and Environmental Sciences
Uncontrolled Keywords:	Panama Isthmus; climate change; late Pliocene; middle Miocene; orocline; seaway closure
Additional Information:	Pdf uploaded in accordance with publisher's policy at http://www.sherpa.ac.uk/romeo/issn/2169-9356/ (accessed 20/02/2014).
Publisher:	American Geophysical Union
ISSN:	2169-9356
Date of First Compliant Deposit:	30 March 2016
Date of Acceptance:	28 February 2012
Last Modified:	07 May 2023 02:26
URI:	https://orca.cardiff.ac.uk/id/eprint/44368

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