{"id":2304,"date":"2019-10-02T19:49:19","date_gmt":"2019-10-02T19:49:19","guid":{"rendered":"https:\/\/www.gsnv.org\/shop\/u-pb-age-constraints-on-magmatism-and-mineralization-in-the-northern-great-basin-nevada\/"},"modified":"2020-02-24T18:16:56","modified_gmt":"2020-02-24T18:16:56","slug":"u-pb-age-constraints-on-magmatism-and-mineralization-in-the-northern-great-basin-nevada","status":"publish","type":"product","link":"https:\/\/www.gsnv.org\/shop\/u-pb-age-constraints-on-magmatism-and-mineralization-in-the-northern-great-basin-nevada\/","title":{"rendered":"U-Pb Age Constraints on Magmatism and Mineralization in the Northern Great Basin, Nevada"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"<p>A U-Pb dating study was undertaken to establish an absolute<br \/>\nage framework for intrusive rocks spatially associated with sediment-<br \/>\nhosted disseminated gold deposits in the northern Great Basin<br \/>\nof Nevada. Forty-four samples were processed, including suites<br \/>\nfrom the Goldstrike\/Meikle, Bald Mountain, Gold Acres\/Cortez,<br \/>\nJerritt Canyon and Ruby Hill areas, as well a suite of regional samples.<br \/>\nCrystallization ages have been established for twenty-six of<br \/>\nthese samples; the remainder either did not yield datable minerals or<br \/>\ndisplayed such complex U-Pb systematics that an age could not be<br \/>\nconfidently assigned. Results of the study indicate that at least four<br \/>\ndiscrete and apparently short-lived magmatic events occurred in the<br \/>\nnorthern Great Basin in Mesozoic and Early Tertiary time; these are<br \/>\ndated at ~186 Ma, ~162-156 Ma, 113-105 Ma, and 38-33 Ma. The<br \/>\nlatter three episodes are widely recognized based upon published<br \/>\ngeochronologic data. In contrast, the late Early Jurassic magmatic<br \/>\nactivity, documented in the Bald Mountain area, has not previously<br \/>\nbeen recognized this far east of the magmatic arc; the regional significance<br \/>\nand extent of this activity is unknown. A variety of ore<br \/>\ndeposits, including base metal porphyry, skarns and mantos and possibly<br \/>\ndistal disseminated sediment-hosted Au-Ag, are spatially and<br \/>\ngenetically associated with intrusions of Middle Jurassic and Early<br \/>\nCretaceous age in the Goldstrike, Bald Mountain, and Ruby Hill<br \/>\nareas. Early Tertiary magmatism is temporally associated with classic<br \/>\nCarlin-type mineralization in many districts and with distal disseminated<br \/>\nstyles of deposits in the Battle Mountain district and elsewhere.<br \/>\nWhen compared to U-Pb ages, many published K-Ar ages on<br \/>\nrelatively unaltered rock units outside of the main hydrothermal centers<br \/>\nin the northern Great Basin are shown to be reasonably reliable.<br \/>\nIn contrast, K-Ar and some Ar-Ar ages from within mineralized districts<br \/>\nhave commonly been disturbed and variably reset by the<br \/>\nhydrothermal processes.<\/p>\n","protected":false},"featured_media":4157,"comment_status":"closed","ping_status":"closed","template":"","meta":{"pmpro_default_level":""},"product_cat":[154],"product_tag":[],"_links":{"self":[{"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product\/2304"}],"collection":[{"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/comments?post=2304"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/media\/4157"}],"wp:attachment":[{"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/media?parent=2304"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product_cat?post=2304"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product_tag?post=2304"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}