John F. Slack
John Slack is a Scientist Emeritus with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.
Science and Products
Filter Total Items: 69
Occurrence and formation of avicennite, Tl2O3 , as a secondary mineral at the Carlin gold deposit, Nevada Occurrence and formation of avicennite, Tl2O3 , as a secondary mineral at the Carlin gold deposit, Nevada
Avicennite, Tl2O3, occurs as grains disseminated in silicified limestones in the upper part of the East ore zone of the Carlin gold deposit, Nevada. The avicennite is formed by the oxidation of carlinite, Tl2S, found in primary unoxidized carbonaceous ore immediately below the avicennite. The grains of avicennite closely resemble carlinite in size and shape. Some avicennite occurs as...
Authors
Arthur S. Radtke, Frank W. Dickson, John F. Slack
Premetamorphic hydrothermal origin of the Tungsten Queen vein, Hamme District, North Carolina, as indicated by mineral textures and minor structures Premetamorphic hydrothermal origin of the Tungsten Queen vein, Hamme District, North Carolina, as indicated by mineral textures and minor structures
The Hamme Tungsten district is a 13-km long, 2-km wide, northeast-trending belt located in northern Vance County, North Carolina and southern Mecklenburg County, Virginia (Fig. 1). The district contains the largest quartz-wolframite-type vein deposits in the United States. Over 50 tungsten-bearing veins occur in this area (Espenshade, 1947), from which more than 1 million short ton units...
Authors
Michael P. Foose, John F. Slack
The Yellow Dog peridotite and a possible buried igneous complex of Lower Keweenawan Age in the northern peninsula of Michigan The Yellow Dog peridotite and a possible buried igneous complex of Lower Keweenawan Age in the northern peninsula of Michigan
Partly serpentinized peridotite of early Keweenawan age crops out in two places along a 20-km-long zone of positive aeromagnetic anomalies in northern Marquette County, Michigan. Most of the area is mantled by Pleistocene drift and the bedrock is not exposed. Petrographic and electron microprobe studies show that the peridotite was originally a plagioclase lherzolite containing 40-50%...
Authors
John S. Klasner, David W. Snider, W.F. Cannon, John F. Slack
Science and Products
Filter Total Items: 69
Occurrence and formation of avicennite, Tl2O3 , as a secondary mineral at the Carlin gold deposit, Nevada Occurrence and formation of avicennite, Tl2O3 , as a secondary mineral at the Carlin gold deposit, Nevada
Avicennite, Tl2O3, occurs as grains disseminated in silicified limestones in the upper part of the East ore zone of the Carlin gold deposit, Nevada. The avicennite is formed by the oxidation of carlinite, Tl2S, found in primary unoxidized carbonaceous ore immediately below the avicennite. The grains of avicennite closely resemble carlinite in size and shape. Some avicennite occurs as...
Authors
Arthur S. Radtke, Frank W. Dickson, John F. Slack
Premetamorphic hydrothermal origin of the Tungsten Queen vein, Hamme District, North Carolina, as indicated by mineral textures and minor structures Premetamorphic hydrothermal origin of the Tungsten Queen vein, Hamme District, North Carolina, as indicated by mineral textures and minor structures
The Hamme Tungsten district is a 13-km long, 2-km wide, northeast-trending belt located in northern Vance County, North Carolina and southern Mecklenburg County, Virginia (Fig. 1). The district contains the largest quartz-wolframite-type vein deposits in the United States. Over 50 tungsten-bearing veins occur in this area (Espenshade, 1947), from which more than 1 million short ton units...
Authors
Michael P. Foose, John F. Slack
The Yellow Dog peridotite and a possible buried igneous complex of Lower Keweenawan Age in the northern peninsula of Michigan The Yellow Dog peridotite and a possible buried igneous complex of Lower Keweenawan Age in the northern peninsula of Michigan
Partly serpentinized peridotite of early Keweenawan age crops out in two places along a 20-km-long zone of positive aeromagnetic anomalies in northern Marquette County, Michigan. Most of the area is mantled by Pleistocene drift and the bedrock is not exposed. Petrographic and electron microprobe studies show that the peridotite was originally a plagioclase lherzolite containing 40-50%...
Authors
John S. Klasner, David W. Snider, W.F. Cannon, John F. Slack