URANIUM-LEAD METHOD OF AGE DETERMINATION

Abstract

Research Article| September 01, 1957 URANIUM-LEAD METHOD OF AGE DETERMINATION: PART II: NORTH AMERICAN LOCALITIES WALTER R ECKELMANN; WALTER R ECKELMANN CARTER RESEARCH LABORATORIES, TULSA. OKLAHOMA; LAMONT GEOLOGICAL OBSERVATORY, COLUMBIA UNIVERSITY, PALISADES, NEW YORK Search for other works by this author on: GSW Google Scholar J LAURENCE KULP J LAURENCE KULP CARTER RESEARCH LABORATORIES, TULSA. OKLAHOMA; LAMONT GEOLOGICAL OBSERVATORY, COLUMBIA UNIVERSITY, PALISADES, NEW YORK Search for other works by this author on: GSW Google Scholar Author and Article Information WALTER R ECKELMANN CARTER RESEARCH LABORATORIES, TULSA. OKLAHOMA; LAMONT GEOLOGICAL OBSERVATORY, COLUMBIA UNIVERSITY, PALISADES, NEW YORK J LAURENCE KULP CARTER RESEARCH LABORATORIES, TULSA. OKLAHOMA; LAMONT GEOLOGICAL OBSERVATORY, COLUMBIA UNIVERSITY, PALISADES, NEW YORK Publisher: Geological Society of America Received: 21 May 1956 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1957, 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 (1957) 68 (9): 1117–1140. https://doi.org/10.1130/0016-7606(1957)68[1117:UMOAD]2.0.CO;2 Article history Received: 21 May 1956 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation WALTER R ECKELMANN, J LAURENCE KULP; URANIUM-LEAD METHOD OF AGE DETERMINATION: PART II: NORTH AMERICAN LOCALITIES. GSA Bulletin 1957;; 68 (9): 1117–1140. doi: https://doi.org/10.1130/0016-7606(1957)68[1117:UMOAD]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 Many new isotopic age determinations by the uranium-lead method have been made on most of the important North American localities from which primary uranium minerals have been reported. With the aid of other published isotopic U-Pb age measurements the writers attempted to interpret the most probable age for each locality and to assign a reasonable uncertainty to that age. The recognition of differential lead loss, the relation of alteration to mineral type, the importance of radon leakage for young samples, and the potential analytical errors make it timely to conduct: such a re-evaluation. Among the well-established ages are: Spruce Pine district, North Carolina, 360 ± 20 m.y.; Portland, Connecticut, 265 ± 10 m.y.; Front Range, Colorado, 59 ± 5 m.y.; Black Hills, South Dakota, 1620 ± 20 m.y.; southeast Manitoba, 2650 ± 100 m.y.; Lake Athabasca, Saskatchewan, 1900 ± 50 m.y.; and the Wilber-force area, 1050 ± 20 m.y. Other probable ages are Bedford, New York, 350 m.y.; Colorado Plateau, 60 m.y.; Coeur d'Alene, 1200 m.y.; and Great Bear Lake, Northwest Territories, 1500 m.y. Although there may have been several regional metamorphic events in the Appalachian Province in the Precambrian, the post-Cambrian effects appear at only two periods centering on 260 m.y. and 360 m.y. The Grenville metamorphism appears limited to a narrow time interval about 1050 m.y. ago. The Front Range and Colorado Plateau uranium mineralization may have been one event occurring about 60 m.y. ago. 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.