Ash-flow fissure vent in west-central Nevada

Abstract

Research Article| April 01, 1976 Ash-flow fissure vent in west-central Nevada E. B. Ekren; E. B. Ekren 1U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar F. M. Byers, Jr. F. M. Byers, Jr. 1U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information E. B. Ekren 1U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, Colorado 80225 F. M. Byers, Jr. 1U.S. Geological Survey, Box 25046, Denver Federal Center, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1976) 4 (4): 247–251. https://doi.org/10.1130/0091-7613(1976)4<247:AFVIWN>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation E. B. Ekren, F. M. Byers; Ash-flow fissure vent in west-central Nevada. Geology 1976;; 4 (4): 247–251. doi: https://doi.org/10.1130/0091-7613(1976)4<247:AFVIWN>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract An east-trending fissure vent filled with welded tuff is well exposed for nearly 1 km on the west flank of Gabbs Valley in northeastern Mineral County, Nevada. In its deepest exposed part, the vent is about 60 m wide. At the top of an exposure, however, where the tuff in the vent merges with an ash-flow tuff cooling unit, the vent is about 460 m wide. The abrupt widening of the vent upward through a vertical distance of only about 400 m from the base of the exposure to the top was probably accomplished by a combination of explosive action and forcible shoving aside of the country rocks.The ash-flow cooling unit continuous with the tuff in the fissure is the youngest of three genetically related units that are sporadically exposed in the vicinity of Gabbs Valley. Stratigraphic and structural relationships in the vicinity of the fissure suggest that the fissure is located on the west flank of a cauldron that is nearly completely buried in Gabbs Valley. The “vent tuff” and the underlying genetically related units in the Gabbs Valley area are highly differentiated rhyolites characterized by high silica and low Ca and Mg contents. The tuffs were erupted 25 m.y. ago at virtually the same time that other chemically and minera-logically similar tuffs were erupted farther to the east in central and east-central Nevada. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.