- 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 ...
A correction applied to observed values obtained in geophysical surveys in order to remove the effect of variations in the observations due to the topography near observation sites.
Industry:Mining
A correction applied to times of seismic reflections measured from an arbitrary time origin. The additive is normally applied for the purpose of translating the time origin to correspond to the datum elevation chosen for computation, and it is algebraic in sign.
Industry:Mining
A correction made to gravity data for the attraction of the rock between the station and the datum elevation (commonly sea level); or, if the station is below the datum elevation, for the rock missing between station and datum. The Bouguer correction is 0.01276 ph mgal/ft, or 0.04185 ph mgal/m, where p is the specific gravity of the intervening rock and h is the difference in elevation between station and datum.
Industry:Mining
A correction necessary in pendulum observations of gravity. The vibrating pendulum produces oscillations of the receiver case, of the pillar, and of the surface soil. Rather complex, coupled vibration phenomena arise and the period of the pendulum itself changes. Numerous methods have been suggested to correct for this influence or to eliminate it. Since the correction is of the order of 10 x 10<sub>-7</sub>to 40 x 10<sub>-7</sub>s on solid rock or cement and may increase to as much as 500 x 10<sub>-7</sub>s on marshy ground, it must be determined accurately.
Industry:Mining
A counterbalance to take the excess weight of the pitwork, or timber beams, in a shaft; used with the Cornish type of reciprocating pump.
Industry:Mining
A counterweighted refractory slab used as a gate or door to a small furnace or oven.
Industry:Mining
A coupling that transmits rotation in only one direction, and disconnects when the torque is reversed.
Industry:Mining
