The Cenozoic structural evolution of a fold-and-thrust belt, northeastern Brooks Range, Alaska

Abstract

Research Article| March 01, 1993 The Cenozoic structural evolution of a fold-and-thrust belt, northeastern Brooks Range, Alaska CATHERINE L. HANKS CATHERINE L. HANKS 1Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775 Search for other works by this author on: GSW Google Scholar Author and Article Information CATHERINE L. HANKS 1Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1993) 105 (3): 287–305. https://doi.org/10.1130/0016-7606(1993)105<0287:TCSEOA>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 CATHERINE L. HANKS; The Cenozoic structural evolution of a fold-and-thrust belt, northeastern Brooks Range, Alaska. GSA Bulletin 1993;; 105 (3): 287–305. doi: https://doi.org/10.1130/0016-7606(1993)105<0287:TCSEOA>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 A Cenozoic fold-and-thrust belt in the eastern structural province of the northeastern Brooks Range exposes polydeformed lowgrade metasedimentary and metavolcanic rocks of the pre-Mississippian basement and its sedimentary cover immediately adjacent to much younger foredeep deposits. Analysis of mesoscopic and map-scale structures in the range-front region suggests that at least one pre-Mississippian deformational event was recorded in the basement sequence by north-vergent fold-and-thrust structures and associated penetrative structures. Most of later Cenozoic shortening of the pre-Mississippian rocks was accommodated by thrust duplication, with little development of penetrative mesoscopic structures. Although separated from the underlying basement rocks by a major regional décollement horizon, Cenozoic deformation in the overlying Mississippian through Lower Cretaceous cover sequence also was primarily by thrust duplication. Although local and regional structural trends within the cover sequence suggest that Cenozoic deformation was north-northwest directed, east-west Cenozoic structural trends within the pre-Mississippian rocks may reflect an inherited pre-Mississippian structural grain and/or pre-Mississippian-age structures reactivated during Cenozoic deformation.A regional balanced cross section of the eastern structural province was constructed by integrating the detailed structural data from the range-front region with subsurface data from the foredeep basin to the north and reconnaissance surface data from the interior of the range. This balanced cross section indicates that Cenozoic shortening across the region was 101 km (63 mi) over an undeformed length of 220 km (137 mi), or 46% 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.