Post–10 Ma uplift and exhumation of the northern Coast Mountains, British Columbia

Research Article| February 01, 2001 Post–10 Ma uplift and exhumation of the northern Coast Mountains, British Columbia K.A. Farley; K.A. Farley 1Division of Geological and Planetary Sciences, MS 170–25, California Institute of Technology, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar M.E. Rusmore; M.E. Rusmore 2Department of Geology, Occidental College, Los Angeles, California 90041, USA Search for other works by this author on: GSW Google Scholar S.W. Bogue S.W. Bogue 2Department of Geology, Occidental College, Los Angeles, California 90041, USA Search for other works by this author on: GSW Google Scholar Geology (2001) 29 (2): 99–102. https://doi.org/10.1130/0091-7613(2001)029<0099:PMUAEO>2.0.CO;2 Article history received: 26 May 2000 rev-recd: 12 Oct 2000 accepted: 26 Oct 2000 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 K.A. Farley, M.E. Rusmore, S.W. Bogue; Post–10 Ma uplift and exhumation of the northern Coast Mountains, British Columbia. Geology 2001;; 29 (2): 99–102. doi: https://doi.org/10.1130/0091-7613(2001)029<0099:PMUAEO>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 Apatite (U-Th)/He ages reveal three distinct periods in the exhumation history of the northern Coast Mountains (∼54°N). A well-developed helium partial retention zone indicates little or no exhumation between ca. 30 and 10 Ma. Beginning at 10 Ma and extending to at least 4 Ma the range underwent steady but slow exhumation of ∼0.22 mm/yr, after which the exhumation rate increased by at least 70%. An 85-km-long He age traverse across the orogen at sea level shows that vertical offsets on post-10 Ma faults are minor. Furthermore, the sea-level He ages (14–2.8 Ma) inversely correlate with local mean elevation along the traverse. These data suggest that the Coast Mountains first appeared as a significant topographic feature only within the past few million years. This history is not consistent with suggestions that uplift of the range resulted from formation of the Queen Charlotte basin in early-middle Miocene time. We speculate that intense erosion by alpine and continental glaciation after 2.5 Ma triggered isostatic uplift and creation of the modern topography of the Coast Mountains. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.