Geology of the Duncan Canal shear zone:Evidence for Early to Middle Jurassic deformation of the Alexander terrane, southeastern Alaska

Research Article| October 01, 1990 Geology of the Duncan Canal shear zone:Evidence for Early to Middle Jurassic deformation of the Alexander terrane, southeastern Alaska WILLIAM C. MCCLELLAND; WILLIAM C. MCCLELLAND 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar GEORGE E. GEHRELS GEORGE E. GEHRELS 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar Author and Article Information WILLIAM C. MCCLELLAND 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 GEORGE E. GEHRELS 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1990) 102 (10): 1378–1392. https://doi.org/10.1130/0016-7606(1990)102<1378:GOTDCS>2.3.CO;2 Article history First Online: 01 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 WILLIAM C. MCCLELLAND, GEORGE E. GEHRELS; Geology of the Duncan Canal shear zone:Evidence for Early to Middle Jurassic deformation of the Alexander terrane, southeastern Alaska. GSA Bulletin 1990;; 102 (10): 1378–1392. doi: https://doi.org/10.1130/0016-7606(1990)102<1378:GOTDCS>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 SocietyGSA Bulletin Search Advanced Search Abstract The Duncan Canal shear zone, central southeastern Alaska, disrupts and penetratively deforms Devonian, Pennsylvanian, and Upper Triassic strata of the lexander terrane. The deformation is interpreted to have occurred within a regime of right-lateral shear during Early or Middle Jurassic time. Clastic and volcanic rocks correlated with the Upper Jurassic and Lower Cretaceous strata of the Gravina belt lack the fabrics characteristic of the deformed Alexander terrane strata and are inferred to unconformably overlie the shear zone. Deformational fabrics of mid-Cretaceous age observed in the Gravina rocks locally truncate and deform the shear-zone strata. Dextral strike-slip faults of Late Cretaceous and (or) Tertiary age that disrupt and modify fabrics of the shear zone are interpreted to accommodate some of the displacement observed on the Clarence Strait fault.The Duncan Canal shear zone extends southward to the Mosman Inlet region on Etolin Island where it projects beneath Jura-Cretaceous Gravina strata. In Duncan Canal and Mosman Inlet, the shear zone evolved within the Alexander terrane and does not coincide with any recognized terrane boundaries. Since the Duncan Canal shear zone is restricted to the currently exposed eastern margin of the Alexander terrane, the shear zone is interpreted to reflect deformation along the eastern margin of the Alexander terrane. 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.