Images

A thick lens of biotite-rich rock, interlayered with thick beds of cross-bedded meta-sandstone + scapolite of the Gunsight Formation of the Lemhi Group in the Lemhi sub-basin of the Mesoproterozoic Belt Basin. The biotite-rich rock is exposed in a prospect pit above the Sweet Repose mine adit.

Blocks of biotitic meta-sandstone from the lower part of the Gunsight Formation, and drill core from the underlying banded siltite unit of the Apple Creek Formation, lying on the dump of the lower workings of the Copper Queen mine, southeast of the Blackbird cobalt-copper mine area.

Outcrop of the banded siltite unit of the Apple Creek Formation, east of the Slippery Gulch fault, and south of the Blackbird cobalt-copper mine area, in the Salmon River Mountains of east-central Idaho.

Quartz vein in biotite-rich rock in the Gunsight Formation of the Mesoproterozoic Lemhi Group. Bluish green copper-bearing minerals coat the quartz vein. Pale pinkish cobalt bloom and white caliche coat adjacent biotite-rich wallrock.

Cross-bedded sandstone of the Gunsight Formation of the Mesoproterozoic Lemhi Group. These beds are interpreted as products of alluvial sedimentation in a deltaic setting.

Figure 3. Secondary electron images of elongate amphibole bundles from the sink fractions of commercial expanded vermiculite ore.

Photo showing intense acid-sulfate hydrothermal alteration on Red Mountain No. 2, Silverton CO. View is looking to the west across Corkscrew Gulch. 

This setup is used for processing water-quality samples at Sowats Point on the Kaibab Plateau.

This view is from Sowats Point on the Kaibab Plateau, looking southwest towards Kanab Creek.

Supergene chrysocolla zone in the Ray porphyry copper mine.

Potash ore is mined at a depth of about 1500 m through a solution mining process. Examination of the world's largest potash producing basin was part of a global assessment of undiscovered.

Stratigraphic studies of Quaternary alluvium provides resource data to the U.S. aggregate industry.

Mine Blast at Silver Bell Mine, Arizona.

Gordon Haxel (USGS, Flagstaff) explains the Jurassic geology of the Baboquivari Mountains, Arizona. Kitt Peak, Arizona, November 2009. Bob Powell (USGS, Tucson) holds the map.

Long-distance shot of headframe in Miami-Globe mining district.

Cathedral Spires in the Black Hills of South Dakota.

Native copper. The USGS studies processes that form copper deposits and reports global production and consumption.

Taking notes on a silicified ridge at Goldfield, Nevada. Silicified ridges are typically associated with epithermal gold deposits.

Kaolinite hill in Cuprite, Nevada is one the premier calibration sites for imaging spectrometers used in mineral mapping.

Deposit of iron-cemented stream gravel (ferricrete) with embedded wood fragments that can be age dated using radiocarbon to determine the age of the ferricrete deposit. Knowing the age of the ferricretes helps scientists determine if the associated enrichment of metals in streams occurred before or after mining in the watershed started.

Mineral Creek watershed in southwestern Colorado has natural and mining-related sources of contamination. In the background of this photo is a large naturally occurring seep that discharges acidic, metal-rich water to a tributary of Mineral Creek.