Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing

Research Article| April 01, 1991 Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing John C. Behrendt; John C. Behrendt 1U.S. Geological Survey, Federal Center, MS 964, Box 25046, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Alan Cooper Alan Cooper 2U.S. Geological Survey, 345 Middlefield Road, MS 999, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Author and Article Information John C. Behrendt 1U.S. Geological Survey, Federal Center, MS 964, Box 25046, Denver, Colorado 80225 Alan Cooper 2U.S. Geological Survey, 345 Middlefield Road, MS 999, Menlo Park, California 94025 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1991) 19 (4): 315–319. https://doi.org/10.1130/0091-7613(1991)019<0315:EORCUO>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation John C. Behrendt, Alan Cooper; Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing. Geology 1991;; 19 (4): 315–319. doi: https://doi.org/10.1130/0091-7613(1991)019<0315:EORCUO>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 SocietyGeology Search Advanced Search Abstract The Cenozoic West Antarctic rift system, characterized by Cenozoic bimodal alkalic volcanic rocks, extends over a largely ice-covered area, from the Ross Sea nearly to the Bellingshausen Sea. It is bounded on one side by a spectacular 4- to 5-km-high rift-shoulder scarp (maximum bedrock relief 5 to 7 km) from northern Victoria Land-Queen Maud Mountains to the Ellsworth-Whitmore-Horlick Mountains. Jurassic tholeiites crop out with the late Cenozoic volcanic rocks along the section of the Transantarctic Mountains from northern Victoria Land to the Horlick Mountains. The Cenozoic rift shoulder diverges here from the Jurassic tholeiite trend, and the tholeiites are exposed discontinuously along the lower elevation (1-2 km) section of the Transantarctic Mountains to the Weddell Sea.Various lines of evidence, no one of which is independently conclusive, lead us (as othershave also suggested) to interpret the following. The Transantarctic Mountains part of the rift shoulder (and probably the entire shoulder) has been rising since about 60 Ma, at episodic rates of ∼1 km/m.y., most recently since mid-Pliocene time, rather than continuously at the mean rate of 100 m/m.y. Uplift rates vary along the scarp, which is cut by transverse faults. We speculate that this uplift may have climatically forced the advance of the Antarctic ice sheet since the most recent warm period. We suggest a possible synergistic relation between episodic tectonism, mountain uplift, and volcanism in the Cenozoic West Antarctic rift system and waxing and waning of the Antarctic ice sheet beginning about earliest Oligocene time. 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.