Filters: Tags: Metavolcanic rocks (X)7 results (76ms)
U-Pb zircon age data from meta-igneous rocks in the Clearwater Mountains, Mount Hayes A-6 Quadrangle, Alaska
We report U-Pb zircon geochronology results for one metavolcanic and one metaplutonic rock sample from the Mount Hayes A-6 Quadrangle of central Alaska. These samples are representative of rock units assigned to the Clearwater terrane of Jones and others (1987), a sequence of greenschist-grade metavolcanic and metasedimentary rocks of poorly constrained age and tectonic origin. Our results indicate a crystallization age of 277.33 +/- 11.84 Ma for a felsic metavolcanic rock, and a 268.05 +/- 11.64 Ma crystallization age for a granitic metaplutonic unit intruding the former.
Analyses of historic U.S. Bureau of Mines rock and heavy mineral concentrate samples for geochemical trace-element and rare-earth element data--Ray Mountains and Kanuti-Hodzana uplands area, Alaska
Re-analyses of sample pulps and bulk rejects from historic USBM rock and heavy-mineral-concentrate samples were conducted by the Alaska Division of Geological & Geophysical Surveys (DGGS) as part of the State of Alaska's Strategic and Critical Minerals Assessment project, which is designed to evaluate Alaska's potential for these resources. The objective of this resource assessment is to expand the state's geochemical database by obtaining and publishing modern, quantitative geochemical analyses for historic USBM samples, where available. Highlights of this re-analysis project include heavy mineral concentrates with up 7,220 ppm Sn, 5,870 ppm Cr, and 17,000 ppm Mn.
Major-oxide and trace-element geochemical data from rocks collected in 2015 in the Tok area, Tanacross A-5, A-6, and parts of adjacent quadrangles, Alaska
The Tok project area is adjacent to the Delta mineral belt volcanogenic massive-sulfide (VMS) district, the Peak gold-silver-copper skarn, and structurally controlled gold and antimony mineralization in the Stibnite Creek and White Gold areas. The project area also includes the Noah prospect, an intrusion-related copper prospect. Whereas the Delta mineral belt has been extensively mapped and explored, the detailed mapping does not continue into the 2015 Tok project area. In this area, only reconnaissance mapping has been conducted. The combination of a lack of detailed mapping, the industry interest in the adjacent areas, and the geophysical data findings prompted the Alaska Division of Geological & Geophysical...
Geochemical major-oxide, minor-oxide, trace-element, and rare-earth-element data from rocks and streams sediments collected in 2012 in the Ray Mountains area, Beaver, Bettles, Livengood, and Tanana quadrangles, Alaska
Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a helicopter-supported geological and geochemical resource assessment project in the Beaver, Bettles, Livengood, and Tanana quadrangles from June 23 through August 5, 2012. The objectives of DGGS's resource assessment are to improve the trace-element geochemical coverage of selected watersheds; to obtain modern, quantitative geochemical analyses; to understand the petrogenesis of the granites; and to better document established mineral occurrences. Stream-sediment, pan-concentrate, and rock sampling were conducted as part of the State's Rare Earth Elements and Strategic Minerals Assessment project, which is...
Geochemical major-oxide, minor-oxide, trace-element, and rare-earth-element data from rock samples collected in 2013 in the Ray Mountains area, Bettles A-1 and A-6 quadrangles, Alaska
In 2012, the State of Alaska established its Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), to evaluate Alaska's statewide potential for SCM resources. The project is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. For decades, the Ray Mountains area of west-central Alaska has been explored for its potential mineral resources. To further assess the rare-earth-element (REE) potential of the State-selected and top-filed lands in the Ray Mountains area, mineral-resource geologists at DGGS carried out a helicopter-supported geological and...
Major-oxide and trace-element geochemical data from rocks collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016
Geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) and University of Alaska carried out a two-part geologic mapping and geochemical sampling project in the Tok River area of the Tanacross A-5 and A-6 quadrangles (June 12-26 and July 8-26). The Tok River area is adjacent to the Delta mineral belt volcanogenic massive-sulfide (VMS) district, the Peak gold-silver-copper skarn, and the structurally controlled gold and antimony mineralization in the Stibnite Creek and White Gold areas. The Tok River project area includes the Noah (also called Hona) prospect, an intrusion-related copper prospect. The combination of insufficient detailed geologic mapping, historical and current industry interest...
This 1:50,000-scale geologic map represents a compilation of the most recent geologic studies of the upper Arkansas River valley, between Leadville and Salida, Colorado. The valley is structurally controlled by an extensional fault system that forms part of the prominent northern Rio Grande rift, an intra-continental region of crustal extension. This work also incorporates new detailed geologic mapping of poorly understood areas within the map area and reinterprets previously studied areas, aided by lidar data that covers 59 percent of the map area. The mapped region extends into the Proterozoic metamorphic and intrusive rocks in the Sawatch Range west of the valley and the Mosquito Range to the east. Paleozoic...