Metallogenic map of volcanogenic massive-sulfide deposits in pre-Tertiary island-arc and ocean-basin environments in Nevada; Volcanogenic massive-sulfide map series

Abstract

Edited by R.L. Earhart EDITOR'S NOTEThe metallogenic map of volcanogenic massive-sulfide occurrences in Nevada is one of several planned or published preliminary and interim products of a study of the distribution and setting of volcanogenic massive sulfides in tl <s western United States. "Volcanogenic massive sulfides" refers to occurrence types that are inferred to be associated with the development of ancient volcanic arcs or with rift systems in a mainly subaqueous environment. Three types of massive-sulfide deposits are shown on this map: (1) Cyprus-type massive-sulfide deposits associated with mafic volcanic rocks of an ophiolite sequence, (2) kuroko-type massive-sulfide deposits associated with felsic and intermediate volcanic rocks of an island-arc environment, and (3) Besshi-type massive-sulfide deposits associated with oceanic sedimentary rocks of .an uncertain, but probably rift, tectonic environment.The distribution of favorable host rocks for massive-sulfide deposits and the lithotectonic terranes in which they occur are also shown on the map. The host rocks shown are not necessarily formal stratigraphic units, and they may contain several lithologic types. They are shown here to delineate areas that may be prospective for undiscovered massive-sulfide deposits.