Asymmetric lithospheric extension: The role of frictional plastic strain softening inferred from numerical experiments

Research Article| March 01, 2002 Asymmetric lithospheric extension: The role of frictional plastic strain softening inferred from numerical experiments Ritske S. Huismans; Ritske S. Huismans 1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada Search for other works by this author on: GSW Google Scholar Christopher Beaumont Christopher Beaumont 1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Ritske S. Huismans 1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada Christopher Beaumont 1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada Publisher: Geological Society of America Received: 31 May 2001 Revision Received: 29 Oct 2001 Accepted: 26 Nov 2001 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (3): 211–214. https://doi.org/10.1130/0091-7613(2002)030<0211:ALETRO>2.0.CO;2 Article history Received: 31 May 2001 Revision Received: 29 Oct 2001 Accepted: 26 Nov 2001 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 Ritske S. Huismans, Christopher Beaumont; Asymmetric lithospheric extension: The role of frictional plastic strain softening inferred from numerical experiments. Geology 2002;; 30 (3): 211–214. doi: https://doi.org/10.1130/0091-7613(2002)030<0211:ALETRO>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 Plane-strain thermomechanical finite element model experiments of lithospheric extension are used to investigate the effects of strain softening in the frictional plastic regime on the asymmetry of extension. Strain softening is considered in cases where the crust is either strongly or weakly coupled to the mantle, and as the extension velocity varies from 0.3 to 30 cm/yr. In the absence of strain softening, extension is symmetric (SS mode). When strain softening takes the form of a reduction in the internal angle of friction with increasing strain, lithospheric extension may be asymmetric at a lithospheric scale (AA mode), or exhibit crustal asymmetry concomitant with mantle symmetry (AS mode). The different styles depend on the relative control of the system by the frictional plastic and ductile layers, which promote asymmetry and symmetry, respectively. High extension velocities and weak ductile crust-mantle coupling tend to suppress the fundamental asymmetry induced by frictional strain softening. This is because they, respectively, increase the effective strength of the lower lithosphere and decrease the control by frictional plasticity. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.