How the Harcuvar Mountains metamorphic core complex became cool: Evidence from apatite (U-Th)/He thermochronometry

Abstract

Research Article| November 01, 2004 How the Harcuvar Mountains metamorphic core complex became cool: Evidence from apatite (U-Th)/He thermochronometry Timothy J. Carter; Timothy J. Carter 1School of Earth Sciences, University of Melbourne, Parkville, Victoria 3010, Australia Search for other works by this author on: GSW Google Scholar Barry P. Kohn; Barry P. Kohn 1School of Earth Sciences, University of Melbourne, Parkville, Victoria 3010, Australia Search for other works by this author on: GSW Google Scholar David A. Foster; David A. Foster 2Department of Geological Sciences, University of Florida, Gainesville, Florida 32611, USA Search for other works by this author on: GSW Google Scholar Andrew J.W. Gleadow Andrew J.W. Gleadow 3School of Earth Sciences, University of Melbourne, Parkville, Victoria 3010, Australia Search for other works by this author on: GSW Google Scholar Geology (2004) 32 (11): 985–988. https://doi.org/10.1130/G20936.1 Article history received: 22 Jun 2004 rev-recd: 04 Aug 2004 accepted: 06 Aug 2004 first online: 03 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 Timothy J. Carter, Barry P. Kohn, David A. Foster, Andrew J.W. Gleadow; How the Harcuvar Mountains metamorphic core complex became cool: Evidence from apatite (U-Th)/He thermochronometry. Geology 2004;; 32 (11): 985–988. doi: https://doi.org/10.1130/G20936.1 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 Apatite (U-Th)/He (AHe) data from ∼60 km of exposed footwall in the Harcuvar Mountains metamorphic core complex, Arizona, reveal a higher-precision late-stage cooling history than previously reported for this complex and others in the region. Progressively younger AHe ages recorded with distance along the slip direction show two distinct trends separated by a sharp inflection. At structurally shallower levels, ages decrease from ca. 23 to 15 Ma toward the northeast, defining an estimated slip rate of 2.6 +0.1/–0.2 km/ m.y. Samples from the structurally deepest ∼35 km of footwall yield concordant ages of ca. 15 Ma (±2σ error limits). The effects of mineralizing fluids, advection of isotherms toward the surface, and flexure-induced erosion are considered, but are unlikely to have influenced the ages. Therefore, it is suggested that the fault slip rate must have increased ca. 15 Ma to a rate of ∼30 km/m.y. Evidence for an increased slip rate ca. 15 Ma has also been observed in other metamorphic core complexes nearby, and this increase is attributed to the thermal effects of a slab-free window on the extending lithosphere. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.