Pseudotachylyte controversy: Fact or friction?

Abstract

Research Article| December 01, 1995 Pseudotachylyte controversy: Fact or friction? John G. Spray John G. Spray 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information John G. Spray 1Department of Geology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (12): 1119–1122. https://doi.org/10.1130/0091-7613(1995)023<1119:PCFOF>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation John G. Spray; Pseudotachylyte controversy: Fact or friction?. Geology 1995;; 23 (12): 1119–1122. doi: https://doi.org/10.1130/0091-7613(1995)023<1119:PCFOF>2.3.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 High-speed slip experiments performed on Westerly granite using friction welding apparatus reveal that comminution is an essential precursor to melting by friction. Observations of slip surfaces via analytical scanning electron microscopy (SEM) document the following sequence of events occurring in 2 s with increasing velocity (up to 2 m/s): fracture; progressive comminution; surface melting of mineral fragments; fragment-to-fragment adhesion; and, finally, production of a fragment-laden, melt-supported suspension. Explosive dehydration and melting of the epidote-group mineral allanite indicates that temperatures of at least 1000 °C were realized at the interface. This is corroborated by calculation of the temperature rise for the known operating conditions. Contrary to earlier proposals, these results show that comminution and frictional melting are complementary and not mutually exclusive processes. Depending on the velocity–shear stress–displacement relations prevailing during frictional slip, rocks produced in seismogenic zones can be predominantly comminuted wall rock or fragment-melt mixes (pseudotachylytes). This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.