Columbite-Group Minerals from New York Pegmatites: Insights from Isotopic and Geochemical Analyses
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Univ Arizona, Dept GeosciIssue Date
2018-05Keywords
NYF pegmatitescolumbite-(Fe)
columbite-(Mn)
Bedford
Manhattan
Neoacadian
U-Pb columbite geochronology
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Lupulescu MV, Chiarenzelli JR, Pecha ME, Singer JW, Regan SP. Columbite-Group Minerals from New York Pegmatites: Insights from Isotopic and Geochemical Analyses. Geosciences. 2018; 8(5):169.Journal
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© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Columbite crystals from niobium-yttrium-fluorine (NYF) pegmatites lacking zircon or containing metamict cyrtolite were analyzed for major and minor elements (Electron Microprobe (EMP)), trace elements (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)), and U-Pb geochronology (Laser AblationMulti-Collector-Inductively Coupled Plasma-Mass Spectrometry (LA-MC-ICP-MS)). All four pegmatite localities sampled are hosted by the Proterozoic Fordham gneiss and/or Paleozoic Bedford gneiss (Columbite-(Fe); Kinkel and Baylis localities) and the Manhattan Schist of Lower Paleozoic age (Columbite-(Mn); Fort George and Harlem River Drive localities) and yield Neoacadian ages. The weighted average U-Pb ages are 372.2 +/- 8.2 Ma (Baylis Quarry), 371.3 +/- 7.3 and 383.4 +/- 8.9 Ma (Kinkel Quarry); 383 +/- 15 Ma (185th St. and Harlem River Drive); and 372 +/- 10 Ma (Fort George). A partial metamict zircon (cyrtolite) from the Kinkel Quarry yielded a weighted average U-Pb age of 376.9 +/- 4.3 Ma. The Neoacadian ages obtained agree with those determined by thermal ionization mass spectrometry (TIMS) for zircon from Lithium-Cesium-Tantalum (LCT) pegmatites from Connecticut and Maine. No pegmatites temporally associated with the Taconic orogeny were found. The size, lack of common Pb, uniform U concentrations across crystal cross-sections, sufficient but moderate uranium concentrations, lack of metamictization, and consistency in U-Pb isotopic ratios for columbite samples BCB-COL, NYSM #25232, and NYSM #525.8 suggests they show promise as potential standards for oxide mineral LA-MC-ICP-MS geochronological analyses, however, additional characterization using ID-TIMS would be necessary to develop as such.Note
Open access journal.ISSN
2076-3263Version
Final published versionSponsors
New York State Museum [1649254]; James Street Fund at St. Lawrence University [1649254]; National Science Foundation NSF [1649254]Additional Links
http://www.mdpi.com/2076-3263/8/5/169ae974a485f413a2113503eed53cd6c53
10.3390/geosciences8050169
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Except where otherwise noted, this item's license is described as © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.