Calcite twinning constraints on late Neogene stress patterns and deformation mechanisms in the active Zagros collision belt

Abstract

Research Article| March 01, 2007 Calcite twinning constraints on late Neogene stress patterns and deformation mechanisms in the active Zagros collision belt O. Lacombe; O. Lacombe 1Université P. et M. Curie-Paris 6, Laboratoire de Tectonique, UMR 7072 CNRS, Paris, France Search for other works by this author on: GSW Google Scholar K. Amrouch; K. Amrouch 1Université P. et M. Curie-Paris 6, Laboratoire de Tectonique, UMR 7072 CNRS, Paris, France Search for other works by this author on: GSW Google Scholar F. Mouthereau; F. Mouthereau 1Université P. et M. Curie-Paris 6, Laboratoire de Tectonique, UMR 7072 CNRS, Paris, France Search for other works by this author on: GSW Google Scholar L. Dissez L. Dissez 27/99 Wellington Street, Bondi, NSW 2026, Australia Search for other works by this author on: GSW Google Scholar Geology (2007) 35 (3): 263–266. https://doi.org/10.1130/G23173A.1 Article history received: 14 Aug 2006 rev-recd: 13 Nov 2006 accepted: 20 Nov 2006 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation O. Lacombe, K. Amrouch, F. Mouthereau, L. Dissez; Calcite twinning constraints on late Neogene stress patterns and deformation mechanisms in the active Zagros collision belt. Geology 2007;; 35 (3): 263–266. doi: https://doi.org/10.1130/G23173A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Mechanically induced calcite twins in veins and host rocks of Late Cretaceous to Miocene age in Iran have been used to determine regional Arabia-Eurasia collisional stresses. A late folding stress regime with a compression oriented 025° (±15°) has been identified across the Zagros belt and the southern Iranian Plateau. This late Neogene stress pattern agrees with the current stress field determined from the focal mechanisms of basement earthquakes and suggests that the Hormuz salt décollement poorly decouples the basement and cover stress fields. Our data show that the collisional state of stress has been relatively constant since ca. 5 Ma. The magnitudes of the stresses obtained from the twinning analysis are unexpectedly low, and, to a first approximation, they are constant across the Zagros simply folded belt. This result supports an overall mechanism of buckling of the detached Zagros cover. Internal viscous-plastic processes help to relieve stress within this cover, thus lowering its seismogenic potential. Beyond these regional implications, this study underlines the potential of paleostress analyses in constraining both the tectonics and the mechanics of ancient and active foreland fold belts. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.