40Ar/39Ar geochronology of Ferrar Dolerite sills from the Transantarctic Mountains, Antarctica: Implications for the age and origin of the Ferrar magmatic province

Research Article| May 01, 1997 40Ar/39Ar geochronology of Ferrar Dolerite sills from the Transantarctic Mountains, Antarctica: Implications for the age and origin of the Ferrar magmatic province T. H. Fleming; T. H. Fleming 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 Search for other works by this author on: GSW Google Scholar A. Heimann; A. Heimann 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 Search for other works by this author on: GSW Google Scholar K. A. Foland; K. A. Foland 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 Search for other works by this author on: GSW Google Scholar D. H. Elliot D. H. Elliot 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 Search for other works by this author on: GSW Google Scholar Author and Article Information T. H. Fleming 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 A. Heimann 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 K. A. Foland 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 D. H. Elliot 1Department of Geological Sciences and Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1997) 109 (5): 533–546. https://doi.org/10.1130/0016-7606(1997)1092.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation T. H. Fleming, A. Heimann, K. A. Foland, D. H. Elliot; 40Ar/39Ar geochronology of Ferrar Dolerite sills from the Transantarctic Mountains, Antarctica: Implications for the age and origin of the Ferrar magmatic province. GSA Bulletin 1997;; 109 (5): 533–546. doi: https://doi.org/10.1130/0016-7606(1997)1092.3.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 Ferrar Dolerite constitutes the hypabyssal phase of the tholeiitic Ferrar Group of Antarctica. Sills with compositions representing most of the range of geochemical variation of the Ferrar Dolerite, and separated by distances of as much as 1400 km, have been analyzed by the 40Ar/39Ar method on feldspar and biotite separates. The 40Ar/39Ar ages for five individual sills range from 176.2 to 177.2 Ma and show no significant difference. These ages reflect crystallization at 176.7 ± 1.8 Ma (where the uncertainty includes provision for systematic uncertainty in the age of the neutron-fluence monitor calibrated relative to MMhb-1 at 513.5 Ma). Combining data from these sills with previous determinations on coeval lavas and underlying pyroclastic units indicates an age of 176.6 ± 1.8 Ma for the Ferrar tholeiitic rocks as a whole. The duration of magmatic activity was less than approximately 1 m.y. By extension, other rocks in the Ferrar magmatic province, which occur from southeastern Australia, along the Transantarctic Mountains to the Theron Mountains, are inferred to have this age. The short duration of magmatic activity as well as the consistent pattern of geochemical variation and distinctiveness of the Ferrar rocks suggest that magmas were transported laterally by an extensive dike swarm which is inferred to have originated in the Weddell Sea sector of the province. 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.