論文

査読有り
2015年3月

Dating of lithospheric buckling: Ar-40/Ar-39 ages of syn-orocline strike-slip shear zones in northwestern Iberia

TECTONOPHYSICS
  • Gabriel Gutierrez-Alonso
  • ,
  • Alan S. Collins
  • ,
  • Javier Fernandez-Suarez
  • ,
  • Daniel Pastor-Galan
  • ,
  • Emilio Gonzalez-Clavijo
  • ,
  • Fred Jourdan
  • ,
  • Arlo B. Weil
  • ,
  • Stephen T. Johnston

643
開始ページ
44
終了ページ
54
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.tecto.2014.12.009
出版者・発行元
ELSEVIER SCIENCE BV

Orogenic curvature is a ubiquitous feature of mountain belts, and the plate tectonic and geodynamic setting responsible for the development of curved orogens is a subject of debate. In order to distinguish between different models of orocline formation it is necessary to tightly constrain the absolute timing of oroclinal development. However, determining the absolute (isotopic) timing of oroclinal bending is challenging. The most direct method available to constrain the time interval during which an orocline formed is to obtain absolute age constraints on fabrics generated within syn-orocline strike-slip shear zones that accommodated rotations around a vertical axis during the development of crustal or lithospheric scale orogenic curvature. Here we present a data set of Ar-40/Ar-39 ages obtained from five shear-zones, some of which display curved traces parallel to the Cantabrian Orocline structural grain in NW Iberia and are interpreted to have been generated coevally to it The Ar-40/Ar-39 ages were obtained by laser-rastering induced step-heating on single muscovite crystals that grew synkinematically during shearing. All five samples yielded ages that cluster tightly at 308 +/- 3 Ma providing direct evidence for the age of oroclinal bending. This age is consistent with the age constraints obtained from paleomagnetic and structural data that place the onset of oroclinal bending in Moscovian times. Our Ar-40/Ar-39 age determinations therefore provide a reliable absolute constraint on the age of buckling of the Variscan orogen around a vertical axis and provide further evidence that oroclinal bending is unrelated to Variscan convergence/collision or the subsequent extensional collapse of the mountain belt. (C) 2014 Elsevier B.V. All rights reserved.

Web of Science ® 被引用回数 : 57

リンク情報
DOI
https://doi.org/10.1016/j.tecto.2014.12.009
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000350836000004&DestApp=WOS_CPL
URL
http://www.scopus.com/inward/record.url?eid=2-s2.0-84923092013&partnerID=MN8TOARS
URL
http://orcid.org/0000-0002-0226-2739

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