- 行业: 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 ...
Rock formation shattered and crisscrossed with fissures and fractures. Compare: broken ground
Industry:Mining
Rock formations that will not stand in the walls of an underground opening without support, such as that offered by cementation, casing, or timber.
Industry:Mining
Rock formations, usually in coal mines, that contain a relatively high proportion of methane. In descensional ventilation, the buoyancy pressure of the methane opposes the ventilating pressure, with a tendency for cavities to contain combustible gases of high concentration. The same may apply to waste cavities with no natural exit to the return.
Industry:Mining
Rock formed by the solidification of molten material that originated within the earth.
Industry:Mining
Rock formed from organic substances, esp. those of vegetable origin, such as coal, oil, resins, and bitumens.
Industry:Mining
Rock forming the ceiling of a cave passage, underground chamber, mine opening, etc.
Industry:Mining
Rock fragments of any size or shape (usually coarse and angular) derived from and lying at the base of a cliff or very steep, rocky slope. Also, the outward sloping and accumulated heap or mass of such loose broken rock, considered as a unit, and formed chiefly by gravitational falling, rolling, or sliding.
Industry:Mining
