Hybrid flow sills: A new mode of igneous sheet intrusion

Abstract

Research Article| April 01, 2010 Hybrid flow sills: A new mode of igneous sheet intrusion Andrew Miles; Andrew Miles * 1Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK *Current address: School of Geosciences, Grant Institute, West Mains Road, Edinburgh EH9 3JW, UK; E-mail: a.j.miles@sms.ed.ac.uk. Search for other works by this author on: GSW Google Scholar Joseph Cartwright Joseph Cartwright 2Seismic 3D Lab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Park Place, Cardiff CF10 3YE, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Andrew Miles * 1Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK Joseph Cartwright 2Seismic 3D Lab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Park Place, Cardiff CF10 3YE, UK *Current address: School of Geosciences, Grant Institute, West Mains Road, Edinburgh EH9 3JW, UK; E-mail: a.j.miles@sms.ed.ac.uk. Publisher: Geological Society of America Received: 21 May 2009 Revision Received: 20 Oct 2009 Accepted: 06 Nov 2009 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (4): 343–346. https://doi.org/10.1130/G30414.1 Article history Received: 21 May 2009 Revision Received: 20 Oct 2009 Accepted: 06 Nov 2009 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 Andrew Miles, Joseph Cartwright; Hybrid flow sills: A new mode of igneous sheet intrusion. Geology 2010;; 38 (4): 343–346. doi: https://doi.org/10.1130/G30414.1 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 Three-dimensional (3-D) seismic mapping of the Vigra sill complex has revealed a series of shallow level lobate sills. This complex was emplaced ca. 55 Ma as part of the igneous activity associated with breakup of the northeast Atlantic margin. The complex consists of discordant sheets, some of which are remarkable in that they have an axial seismic amplitude anomaly along their lengths. The anomalies are interpreted as evidence for the development of magma tubes that formed in the subsurface at depths between 200 and 400 m, and that fed the lobate sill segments. We argue that this sill complex represents a hybrid between expansion of sheets by flow and fracture propagation. These hybrid flow sills are suggested to result from magma emplacement into high-porosity and water-saturated sediments at low confining pressures, where the coalescence of flow lobes results in the formation of magma tubes capable of propagating >8 km and terminating in the formation of new flow lobes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.