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PETROGRAPHY AND RADIOACTIVITY OF FOUR PALEOZOIC MAGMA SERIES IN NEW HAMPSHIRE

1946; Geological Society of America; Volume: 57; Issue: 9 Linguagem: Inglês

10.1130/0016-7606(1946)57[797

1943-2674

Marland P. Billings, N. B. Keevil,

Geochemistry and Geologic Mapping

Research Article| September 01, 1946 PETROGRAPHY AND RADIOACTIVITY OF FOUR PALEOZOIC MAGMA SERIES IN NEW HAMPSHIRE M. P BILLINGS; M. P BILLINGS HARVARD UNIVERSITY, CAMBRIDGE, MASS. Search for other works by this author on: GSW Google Scholar N. B KEEVIL N. B KEEVIL HARVARD UNIVERSITY, CAMBRIDGE, MASS. Search for other works by this author on: GSW Google Scholar Author and Article Information M. P BILLINGS HARVARD UNIVERSITY, CAMBRIDGE, MASS. N. B KEEVIL HARVARD UNIVERSITY, CAMBRIDGE, MASS. Publisher: Geological Society of America Received: 25 Feb 1946 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1946, 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 (1946) 57 (9): 797–828. https://doi.org/10.1130/0016-7606(1946)57[797:PAROFP]2.0.CO;2 Article history Received: 25 Feb 1946 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation M. P BILLINGS, N. B KEEVIL; PETROGRAPHY AND RADIOACTIVITY OF FOUR PALEOZOIC MAGMA SERIES IN NEW HAMPSHIRE. GSA Bulletin 1946;; 57 (9): 797–828. doi: https://doi.org/10.1130/0016-7606(1946)57[797:PAROFP]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 The Ordovician (?), Silurian, and Devonian strata of New Hampshire are intruded by igneous rocks belonging to four magma series, the oldest of which is late Ordovician (?), the youngest of which is Mississippian (?). Each magma series consists of rocks ranging from gabbro, diorite, or quartz diorite to granite.Although individual specimens from a rock type within a single magma series commonly show considerable range in radioactivity, the average values show a progressive increase in radioactivity toward the granitic end of the series, which is three to four times as radioactive as the gabbro-diorite end of the series. The reason for this increase toward the granitic end of the series is not always clear, but in the White Mountain magma series this appears to be due to an increase in the amount of allanite and probably zircon. This magma series is twice as radioactive as the other magma series and considerably more radioactive than similar rocks elsewhere in North America. It is suggested that the parental basaltic magma from which the White Mountain magma series was differentiated was more radioactive than the primary magmas from which the older magma series were derived. 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.