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Timing of anatexis in metapelites from the Adirondack lowlands and southern highlands: A manifestation of the Shawinigan orogeny and subsequent anorthosite-mangerite-charnockite-granite magmatism

2006; Geological Society of America; Volume: 118; Issue: 11-12 Linguagem: Inglês

10.1130/b25927.1

1943-2674

M. J. Heumann, M. E. Bickford, Barbara M. Hill, J. M. McLelland, Bruce Selleck, Michael J. Jercinovic,

Geology and Paleoclimatology Research

Research Article| November 01, 2006 Timing of anatexis in metapelites from the Adirondack lowlands and southern highlands: A manifestation of the Shawinigan orogeny and subsequent anorthosite-mangerite-charnockite-granite magmatism Matthew J. Heumann; Matthew J. Heumann 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar M.E. Bickford; M.E. Bickford 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar Barbara M. Hill; Barbara M. Hill 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar James M. McLelland; James M. McLelland 2Department of Geology, Colgate University, Hamilton, New York 13346, USA Search for other works by this author on: GSW Google Scholar Bruce W. Selleck; Bruce W. Selleck 2Department of Geology, Colgate University, Hamilton, New York 13346, USA Search for other works by this author on: GSW Google Scholar Michael J. Jercinovic Michael J. Jercinovic 3Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003-9297, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Matthew J. Heumann 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA M.E. Bickford 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Barbara M. Hill 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA James M. McLelland 2Department of Geology, Colgate University, Hamilton, New York 13346, USA Bruce W. Selleck 2Department of Geology, Colgate University, Hamilton, New York 13346, USA Michael J. Jercinovic 3Department of Geosciences, University of Massachusetts, Amherst, Massachusetts 01003-9297, USA Publisher: Geological Society of America Received: 03 Nov 2005 Revision Received: 23 Mar 2006 Accepted: 29 Apr 2006 First Online: 03 Oct 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2006) 118 (11-12): 1283–1298. https://doi.org/10.1130/B25927.1 Article history Received: 03 Nov 2005 Revision Received: 23 Mar 2006 Accepted: 29 Apr 2006 First Online: 03 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Matthew J. Heumann, M.E. Bickford, Barbara M. Hill, James M. McLelland, Bruce W. Selleck, Michael J. Jercinovic; Timing of anatexis in metapelites from the Adirondack lowlands and southern highlands: A manifestation of the Shawinigan orogeny and subsequent anorthosite-mangerite-charnockite-granite magmatism. GSA Bulletin 2006;; 118 (11-12): 1283–1298. doi: https://doi.org/10.1130/B25927.1 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 Anatectic leucogranites are common in metapelites within both the highlands and lowlands terranes of the Adirondack Mountains of northern New York State. The formation of these igneous bodies, which are folded in the lowlands and commonly mylonitized in the highlands, has been widely considered an event accompanying the ca. 1050 Ma Ottawan orogeny, during which metamorphic grade reached granulite facies in the highlands, while the lowlands experienced amphibolite facies metamorphism. Sensitive high-resolution ion microprobe (SHRIMP) analyses of zircons separated from leucosomes and melanosomes in both the southern highlands and the lowlands indicate that primary anatexis occurred ca. 1180–1160 Ma, and is thus a manifestation of heating during the earlier Shawinigan orogeny (ca. 1210–1160 Ma) and associated anorthosite-mangerite-charnockite-granite (AMCG) magmatism (ca. 1165–1150 Ma). The absence of Ottawan overgrowths on Shawinigan zircons in these leucosomes suggests that by Ottawan time the rocks were too dry for further melting or zircon growth to occur. However, electron microprobe analyses of monazites from the southern highlands reveal multiple age zones, including cores with ages of ca. 1170–1180 Ma, consistent with primary growth during Shawinigan orogenesis, complex zones formed ca. 1140–1155 Ma during AMCG magmatism, and ca. 1050–1020 Ma formed during Ottawan orogenesis and high-grade metamorphism. Throughout the Adirondacks, leucosomes and melanosomes contain older, ca. 1320 Ma, zircons that are considered to be remnant detrital zircons derived from arc rocks of the Elzevirian terrane. The apparent absence of Archean detrital zircons suggests that the protoliths of the metapelites were deposited in restricted basins that did not receive detritus from the Superior craton. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.