MAJOR-ELEMENT GEOCHEMISTRY OF THE SILENT CANYON-BLACK MOUNTAIN PERALKALINE VOLCANIC CENTERS, NORTHWESTERN NEVADA TEST SITE: APPLICATIONS TO AN ASSESSMENT OF RENEWED VOLCANISM

摘要

The Silent Canyon and Black Mountain volcanic centers are located in the northern part of the Nevada Test Site. The Silent Canyon volcanic center is a buried cauldron complex of Miocene age (13-15 m.y.). Black Mountain volcanic center is an elliptical-shaped cauldron complex of late Miocene age.nThe lavas and tuffs of the two centers comprise a subalkaline-peralkaline association. Rock types range from quartz normative subalkaline tracheae and hyalite to peralkaline comedies. The Gold Flat Member of the Thirsty Canyon Tuff (Black Mountain) is a pantellerite.