- Industry: Mining
- Number of terms: 33118
- Number of blossaries: 0
- Company Profile:
The U.S. Bureau of Mines (USBM) was the primary United States Government agency conducting scientific research and disseminating information on the extraction, processing, use, and conservation of mineral resources.
Founded on May 16, 1910, through the Organic Act (Public Law 179), USBM's missions ...
An obsolete term for blende, a zincblende or the sulfide of zinc (sphalerite), which has the luster and often the color of common resin and yields a white streak and powder.
Industry:Mining
An obsolete term for decomposition of organic matter under conditions of insufficient oxygen.
Industry:Mining
An obsolete term synonymous with porphyry. The term was originally used to distinguish porphyries that contain plagioclase phenocrysts from those that contain alkali feldspar phenocrysts.
Industry:Mining
An obsolete term variously used to denote a volcanic rock and selenian sulfur.
Industry:Mining
An obsolete type of magnetometer used for mapping high-amplitude magnetic anomalies. It consists of a magnetized needle pivoted to rotate freely in a vertical plane, with an adjustable weight on the south side of the magnet.
Industry:Mining
An obsolete water-raising apparatus consisting of a swinging frame carrying a double series of troughs ascending in zigzag lines, and so adjusted to each other that as the frame rocks in either direction water may be passed to a higher level.
Industry:Mining
An obsolete, nucleonic coal-sensing instrument that can measure the thickness of coal left on the roof or floor of a seam after the passage of a mining machine. The principle used is the measurement of the density of the strata underlying the machine by a gammaray backscattering unit. Gamma rays from a radioactive source are scattered in all directions by the atomic particles in the coal and rock. The amount of scattered radiation eventually reaching the Geiger counter is, approx., inversely proportional to the density of the scattering medium; i.e., more radiation will come back from coal than from rock. Thus, as the amount of coal between the source and the underlying rock changes, so the amount reaching the Geiger counter and the counting unit (the ratemeter) will change, and consequently the output of the meter can be calibrated in terms of the thickness of the floor coal. This instrument has been replaced by a natural-gamma coal thickness sensor.
Industry:Mining
An obstruction inside a bit, reaming shell, or core barrel consisting of impacted core fragments or drill cuttings, which prevents entry of core into the core barrel.
Industry:Mining
