Research Article| September 01, 1966 Geomagnetic Polarity Epochs: Pribilof Islands, Alaska ALLAN COX; ALLAN COX U. S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar DAVID M HOPKINS; DAVID M HOPKINS U. S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar G BRENT DALRYMPLE G BRENT DALRYMPLE U. S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar Author and Article Information ALLAN COX U. S. Geological Survey, Menlo Park, California DAVID M HOPKINS U. S. Geological Survey, Menlo Park, California G BRENT DALRYMPLE U. S. Geological Survey, Menlo Park, California Publisher: Geological Society of America Received: 23 Aug 1965 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1966, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1966) 77 (9): 883–910. https://doi.org/10.1130/0016-7606(1966)77[883:GPEPIA]2.0.CO;2 Article history Received: 23 Aug 1965 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation ALLAN COX, DAVID M HOPKINS, G BRENT DALRYMPLE; Geomagnetic Polarity Epochs: Pribilof Islands, Alaska. GSA Bulletin 1966;; 77 (9): 883–910. doi: https://doi.org/10.1130/0016-7606(1966)77[883:GPEPIA]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 SocietyGSA Bulletin Search Advanced Search Abstract A comparison was made between geologic, radiometric, and paleomagnetic methods of dating and stratigraphic correlation on the Pribilof Islands of Alaska. Age relationships based on geomorphology and paleontology agree with those determined using potassium-argon dating and paleomagnetic reversals, permitting the following synthesis of the geologic and geomagnetic history of the Pribilofs: The two islands formed during two pulses of volcanism separated by about 1 m.y. St. George Island was formed during the earlier pulse, which lasted from 2.2 to at least 1.6 m.y. ago. During this short interval of 0.6 m.y. the geomagnetic field changed polarity from an initial reversed direction to a normal direction and then back again to a reversed direction. The normal flows, which are both underlain and overlain by reversed flows, have ages between 2.0 and 1.8 m.y. They were extruded during the Olduvai normal event, a relatively brief interval of worldwide normal geomagnetic polarity within the otherwise reversed Matuyama polarity epoch, which lasted from 2.5 to 0.7 m.y. ago. A second pulse of volcanism, which began about 1 m.y. after the first, produced St. Paul Island. This pulse has continued for the past one third m.y., an interval of normal polarity.Fossiliferous marine sedimentary rocks deposited during the Beringian marine transgression are covered on St. George Island by a reversely magnetized pillow lava 2.14 ± 0.08 m.y. old. Fossiliferous marine sedimentary rocks deposited during a transgression younger than the Anvilian and older than the Kotzebuan transgressions are bracketed at the Einahnuhto Bluffs, St. Paul, between normally magnetized lava flows and are less than 0.4 and more than 0.1 m.y. old. 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.
No takes yet. Share an insight, caveat, or question.
Cox et al. (1966) studied this question.