02367nas a2200241   4500008004100000245011500041210006900156260001200225300000800237490000600245520158200251653002501833653001701858653002301875653004701898653002601945653003001971100002602001700002202027700001602049700001802065856004202083       2018                        eng d00aAge and Origin of the Mesoproterozoic Iron Oxide-Apatite Mineralization, Cheever Mine, Eastern Adirondacks, NY0 aAge and Origin of the Mesoproterozoic Iron OxideApatite Minerali  c09/2018  a3450 v83 a<p>At the Cheever Mine, located in the eastern Adirondack Mountains of the Mesoproterozoic Grenville Province, iron oxide-apatite ore forms a narrow (&lt;3 m) sheet cross-cutting metasomatically altered, magnetite-bearing, albite-rich leucogranitic host rocks of the Lyon Mountain Granite suite. Zircon from the ore and five samples of country rock were dated by Laser Ablation-Multi-Collector-Inductively Coupled Plasma-Mass Spectrometry. The ore yielded a Concordia age of 1033.6 ± 2.9 Ma while three samples of host rock yielded ages of 1036.3 ± 2.9, 1040 ± 11, and 1043.9 ± 4.1 Ma. Two additional samples of host rock yielded older ages of 1059.6 ± 3.4 and 1066.0 ± 6.3 Ma and contain zircon xenocrystic cores with <sup>207</sup>Pb/<sup>206</sup>Pb ages up to 1242 Ma. The zircons analyzed, including those separated from the ore, have characteristics typically associated with an igneous origin including size, shape, inclusions, oscillatory zoning, typical chondrite-normalized REE patterns, U contents, and U/Th ratios. This data establishes the age of the ore and alteration and a temporal, and likely genetic, connection between the ore and members of the Lyon Mountain Granite suite. A model invoking melting of Shawinigan country rocks, magmatic differentiation, and long-lived magmatic and metasomatic input along extensional fault conduits is proposed for the ore’s genesis. At the Cheever Mine, magmatic hydrothermal fluids and/or post-intrusion alteration appears not to have had a major impact on zircon, which preserves original U-Pb systematics.</p>
10aAdirondack Mountains10aCheever Mine10aGrenville Province10airon oxide-apatite deposits (IOA deposits)10aLyon Mountain Granite10aU-Pb zircon geochronology1 aChiarenzelli, Jeffrey1 aLupulescu, M., V.1 aRegan, Sean1 aSinger, Jared  uhttp://www.mdpi.com/2076-3263/8/9/345