Microstructural dynamics of central uplifts: Reidite offset by zircon twins at the Woodleigh impact structure, Australia

Abstract

Research Article| September 27, 2018 Microstructural dynamics of central uplifts: Reidite offset by zircon twins at the Woodleigh impact structure, Australia Morgan A. Cox; Morgan A. Cox * 1Space Science and Technology Centre (SSTC), School of Earth and Planetary Science, Curtin University, Perth, Western Australia 6102, Australia *E-mail: morgan.cox@student.curtin.edu.au Search for other works by this author on: GSW Google Scholar Aaron J. Cavosie; Aaron J. Cavosie 1Space Science and Technology Centre (SSTC), School of Earth and Planetary Science, Curtin University, Perth, Western Australia 6102, Australia Search for other works by this author on: GSW Google Scholar Phil A. Bland; Phil A. Bland 1Space Science and Technology Centre (SSTC), School of Earth and Planetary Science, Curtin University, Perth, Western Australia 6102, Australia Search for other works by this author on: GSW Google Scholar Katarina Miljković; Katarina Miljković 1Space Science and Technology Centre (SSTC), School of Earth and Planetary Science, Curtin University, Perth, Western Australia 6102, Australia Search for other works by this author on: GSW Google Scholar Michael T.D. Wingate Michael T.D. Wingate 2Geological Survey of Western Australia, Department of Mines, Industry Regulation and Safety, Perth, Western Australia 6004, Australia Search for other works by this author on: GSW Google Scholar Geology (2018) 46 (11): 983–986. https://doi.org/10.1130/G45127.1 Article history received: 09 May 2018 rev-recd: 10 Sep 2018 accepted: 11 Sep 2018 first online: 27 Sep 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Morgan A. Cox, Aaron J. Cavosie, Phil A. Bland, Katarina Miljković, Michael T.D. Wingate; Microstructural dynamics of central uplifts: Reidite offset by zircon twins at the Woodleigh impact structure, Australia. Geology 2018;; 46 (11): 983–986. doi: https://doi.org/10.1130/G45127.1 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 Impact cratering is a dynamic process that is violent and fast. Quantifying processes that accommodate deformation at different scales during central uplift formation in complex impact structures is therefore a challenging task. The ability to correlate mineral deformation at the microscale with macroscale processes provides a critical link in helping to constrain extreme crustal behavior during meteorite impact. Here we describe the first high-pressure-phase–calibrated chronology of shock progression in zircon from a central uplift. We report both shock twins and reidite, the high-pressure ZrSiO4 polymorph, in zircon from shocked granitic gneiss drilled from the center of the >60-km-diameter Woodleigh impact structure in Western Australia. The key observation is that in zircon grains that contain reidite, which forms at >30 GPa during the crater compression stage, the reidite domains are systematically offset by later-formed shock deformation twins (∼20 GPa) along extensional planar microstructures. The {112} twins are interpreted to record crustal extension and uplift caused by the rarefaction wave during crater excavation. These results provide the first physical evidence that relates the formation sequence of both a high-pressure phase and a diagnostic shock microstructure in zircon to different cratering stages with unique stress regimes that are predicted by theoretical and numerical models. These microstructural observations thus provide new insight into central uplift formation, one of the least-understood processes during complex impact crater formation, which can produce many kilometers of vertically uplifted bedrock in seconds. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.