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Chlorine in mantle-derived carbonatite melts revealed by halite in the St.-Honoré intrusion (Québec, Canada)

2015; Geological Society of America; Volume: 43; Issue: 8 Linguagem: Inglês

10.1130/g36843.1

1943-2682

Vadim S. Kamenetsky, Roger H. Mitchell, Roland Maas, Andrea Giuliani, Damien Gaboury, L. Zhitova,

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Research Article| August 01, 2015 Chlorine in mantle-derived carbonatite melts revealed by halite in the St.-Honoré intrusion (Québec, Canada) Vadim S. Kamenetsky; Vadim S. Kamenetsky * 1School of Physical Sciences, University of Tasmania, Hobart, TAS 7001, Australia *E-mail: Dima.Kamenetsky@utas.edu.au Search for other works by this author on: GSW Google Scholar Roger H. Mitchell; Roger H. Mitchell 2Department of Geology, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada Search for other works by this author on: GSW Google Scholar Roland Maas; Roland Maas 3School of Earth Sciences, University of Melbourne, Melbourne, VIC 3010, Australia Search for other works by this author on: GSW Google Scholar Andrea Giuliani; Andrea Giuliani 3School of Earth Sciences, University of Melbourne, Melbourne, VIC 3010, Australia Search for other works by this author on: GSW Google Scholar Damien Gaboury; Damien Gaboury 4Département des sciences appliqués, Université du Québec à Chicoutimi, Chicoutimi, Québec G7H 2B1, Canada Search for other works by this author on: GSW Google Scholar Liudmila Zhitova Liudmila Zhitova 5Novosibirsk State University, Novosibirsk 630090, Russia Search for other works by this author on: GSW Google Scholar Author and Article Information Vadim S. Kamenetsky * 1School of Physical Sciences, University of Tasmania, Hobart, TAS 7001, Australia Roger H. Mitchell 2Department of Geology, Lakehead University, Thunder Bay, Ontario P7B 5E1, Canada Roland Maas 3School of Earth Sciences, University of Melbourne, Melbourne, VIC 3010, Australia Andrea Giuliani 3School of Earth Sciences, University of Melbourne, Melbourne, VIC 3010, Australia Damien Gaboury 4Département des sciences appliqués, Université du Québec à Chicoutimi, Chicoutimi, Québec G7H 2B1, Canada Liudmila Zhitova 5Novosibirsk State University, Novosibirsk 630090, Russia *E-mail: Dima.Kamenetsky@utas.edu.au Publisher: Geological Society of America Received: 01 Apr 2015 Revision Received: 29 May 2015 Accepted: 30 May 2015 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2015 Geological Society of America Geology (2015) 43 (8): 687–690. https://doi.org/10.1130/G36843.1 Article history Received: 01 Apr 2015 Revision Received: 29 May 2015 Accepted: 30 May 2015 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Vadim S. Kamenetsky, Roger H. Mitchell, Roland Maas, Andrea Giuliani, Damien Gaboury, Liudmila Zhitova; Chlorine in mantle-derived carbonatite melts revealed by halite in the St.-Honoré intrusion (Québec, Canada). Geology 2015;; 43 (8): 687–690. doi: https://doi.org/10.1130/G36843.1 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 SocietyGeology Search Advanced Search Abstract Mantle-derived carbonatites are igneous rocks dominated by carbonate minerals. Intrusive carbonatites typically contain calcite and, less commonly, dolomite and siderite as the only carbonate minerals. In contrast, lavas erupted by the only active carbonatite volcano on Earth, Oldoinyo Lengai, Tanzania, are enriched in Na-rich carbonate phenocrysts (nyerereite and gregoryite) and Na-K halides in the groundmass. The apparent paradox between the compositions of intrusive and extrusive carbonatites has not been satisfactorily resolved. This study records the fortuitous preservation of halite in the intrusive dolomitic carbonatite of the St.-Honoré carbonatite complex (Québec, Canada), more than 490 m below the present surface. Halite occurs intergrown with, and included in, magmatic minerals typical of intrusive carbonatites; i.e., dolomite, calcite, apatite, rare earth element fluorocarbonates, pyrochlore, fluorite, and phlogopite. Halite is also a major daughter phase of melt inclusions hosted in early magmatic minerals, apatite and pyrochlore. The carbon isotope composition of dolomite (δ13C = −5.2‰) and Sr-Nd isotope compositions of individual minerals (87Sr/86Sri = 0.70287 in apatite, to 0.70443 in halite; εNd = +3.2 to +4.0) indicate a mantle origin for the St.-Honoré carbonatite parental melt. More radiogenic Sr compositions of dolomite and dolomite-hosted halite and heavy oxygen isotope composition of dolomite (δ18O = +23‰) suggest their formation at some time after magma emplacement by recrystallization of original magmatic components in the presence of ambient fluids. Our observations indicate that water-soluble chloride minerals, common in the modern natrocarbonatite lavas, can be significant but ephemeral components of intrusive carbonatite complexes. We therefore infer that the parental magmas that produce primary carbonatite melts might be enriched in Na and Cl. This conclusion affects existing models for mantle source compositions, melting scenarios, temperature, rheological properties, and crystallization path of carbonatite melts. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.