Uniquely extensive seismite from the latest Triassic of the United Kingdom: Evidence for bolide impact?

Abstract

Research Article| June 01, 2003 Uniquely extensive seismite from the latest Triassic of the United Kingdom: Evidence for bolide impact? Michael J. Simms Michael J. Simms 1Department of Geology, Ulster Museum, National Museums & Galleries of Northern Ireland, Botanic Gardens, Belfast BT9 5AB, Northern Irel Search for other works by this author on: GSW Google Scholar Geology (2003) 31 (6): 557–560. https://doi.org/10.1130/0091-7613(2003)031<0557:UESFTL>2.0.CO;2 Article history received: 28 Nov 2002 rev-recd: 07 Mar 2003 accepted: 10 Mar 2003 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michael J. Simms; Uniquely extensive seismite from the latest Triassic of the United Kingdom: Evidence for bolide impact?. Geology 2003;; 31 (6): 557–560. doi: https://doi.org/10.1130/0091-7613(2003)031<0557:UESFTL>2.0.CO;2 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 A 2–4 m thick seismite, in places overlain by a previously unreported tsunamite, can be traced across >250,000 km2 of the outcrop and subcrop of the latest Triassic (Rhaetian) Cotham Member of the Penarth Group, United Kingdom, an extent unique for the British Phanerozoic. Its consistent thickness, intensity of deformation, and preferred orientations of slump-fold axes indicate a seismic event of M > 10 with an epicenter >600 km W or NW of central Britain. The magnitude of the event is incompatible with known terrestrial mechanisms (fault, volcano) but is consistent with a major bolide impact. A short, but unknown, interval separates the top of the Cotham Member seismite from major geochemical and biotic perturbations associated with the end-Triassic extinction, although a direct link between the seismite and these other events remains equivocal. The exceptional extent of "mega-seismites" such as this may prove a useful indicator of previously undocumented bolide impacts. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.