- 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 ...
A peculiar green and very pure glass, found as rolled pebbles. Also called bottle stone; pseudochrysolite--the latter from its resemblance to olivine. It is not solely a rock, as it may be prehistoric slag or glass.
Industry:Mining
A peculiar method of surface decay by which granite or granite gneisses are left with a corrugated or fluted surface. In a large subangular fragment of granite, one side contains a dozen of these little channels, from 1 to 4 in (2.5 to 10.2 cm) deep and from 3 to 10 in (7.6 to 25.4 cm) apart from center to center. These channels run straight down the face of the rock.
Industry:Mining
A pegmatite body characterized by pneumatolytic-hydrothermal replacement and rare minerals.
Industry:Mining
A pendulum having almost no tendency to take a definite position of equilibrium.
Industry:Mining
A penetration test in which the testing device is pushed into soil with a measurable force, as distinct from a dynamic penetration test in which the testing device is driven into the ground by blows from a standard hammer.
Industry:Mining
A peralkaline rhyolite or quartz trachyte with normative quartz exceeding 10%. It is more mafic than comendite.
Industry:Mining
A percussive boring system comprising a closed-in derrick over the crown pulley of which a steel rope is passed from its containing drum. The boring tools are suspended from the end of the rope and are moved in the hole as required by means of the drum. A walking beam, operated by a driving mechanism, gives the boring tools a rapid vibrational motion.
Industry:Mining
A percussive drill for prospecting through superficial deposits. The drill is given a short stroke, 10 to 20 cm, and rotated by hand. Water is pumped down through the hollow steel rods and escapes through openings in the chopping bit. Casing is used, and the drilling rate is from 6 to 12 m per shift.
Industry:Mining
A percussive or hammer drill in which the bit-driven mechanism is located immediately behind the drill bit and is small enough in diameter to permit it to enter and follow the bit down into the hole drilled.
Industry:Mining
