{"id":2288,"date":"2019-10-02T19:48:47","date_gmt":"2019-10-02T19:48:47","guid":{"rendered":"https:\/\/www.gsnv.org\/shop\/new-perspectives-on-the-geology-and-origin-of-the-northern-nevada-rift\/"},"modified":"2020-02-24T18:16:49","modified_gmt":"2020-02-24T18:16:49","slug":"new-perspectives-on-the-geology-and-origin-of-the-northern-nevada-rift","status":"publish","type":"product","link":"https:\/\/www.gsnv.org\/shop\/new-perspectives-on-the-geology-and-origin-of-the-northern-nevada-rift\/","title":{"rendered":"New Perspectives on the Geology and Origin of the Northern Nevada Rift"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"<p>ABSTRACT<br \/>\nThe northern Nevada rift is a term applied to a prominent,<br \/>\nnorth-northwest-trending aeromagnetic anomaly that extends about<br \/>\n500 km from near the Nevada-Oregon border to southeast Nevada.<br \/>\nIts surface trace is marked in places by an alignment of middle<br \/>\nMiocene volcanic and hypabyssal rocks and epithermal gold-silver<br \/>\nand mercury deposits that formed during west-southwest-east-northeast<br \/>\ndirected extension. On regional aeromagnetic maps, the rift<br \/>\nappears as a narrow positive anomaly that probably reflects the presence<br \/>\nof abundant intrusive mafic rocks emplaced mostly between<br \/>\nabout 16.5 and 15 Ma. The rift may correspond in part to a pre-<br \/>\nCenozoic deep crustal structure that was reactivated during the late<br \/>\nCenozoic. Thermal bulging and shallow intrusion of mafic magmas<br \/>\nrelated to the Yellowstone hot spot near McDermitt led to the inception<br \/>\nof the rift at about 16.5 Ma and rapid propagation of the rift to<br \/>\nthe south. The northern Nevada rift evolved in a manner similar to<br \/>\nthe Mid-Continent rift of North America and dissimilar to many<br \/>\nintracontinental rifts, such as the long-lived Rio Grande rift.<br \/>\nHowever, duration of rifting along the northern Nevada rift was<br \/>\nshort (mostly between about 16.5 to 15 Ma), the total amount of<br \/>\nextension of the crust along the rift was generally less than a few<br \/>\nkilometers, and the amount of subsidence was generally less than 1<br \/>\nkilometer. Interbedded sedimentary deposits generally are uncommon<br \/>\nalong the rift, and the total volume of igneous rocks erupted<br \/>\nalong the rift also was small.<br \/>\nThree distinct groups of middle Miocene igneous rocks are<br \/>\nassociated with the rift: an early group of mafic (basalt to andesite)<br \/>\ncompositions and later groups of trachydacite and rhyolite compositions.<br \/>\nThe early mafic magmas probably were related to the<br \/>\nYellowstone hot spot and were derived from upper mantle magmas.<br \/>\nThe more silicic compositions probably represent lower crustal melts<br \/>\nthat may have formed as a result of hot-spot-related deep crustal heating.<br \/>\nAll magmas had low oxygen fugacities and low water contents.<\/p>\n","protected":false},"featured_media":4076,"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\/2288"}],"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=2288"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/media\/4076"}],"wp:attachment":[{"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/media?parent=2288"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product_cat?post=2288"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.gsnv.org\/wp-json\/wp\/v2\/product_tag?post=2288"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}