- 行业: Mining
- Number of terms: 33118
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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 ...
Said of a mineral deposit (esp. of metals) in which the desired minerals occur as scattered particles in the rock, but in sufficient quantity to make the deposit an ore. Some disseminated deposits are very large. Compare: impregnated
Industry:Mining
Said of a mineral deposit confined to a single stratigraphic unit. The term can refer to a stratiform deposit, to variously oriented orebodies contained within the unit, or to a deposit containing veinlets and alteration zones that may or may not be strictly conformable with bedding.
Industry:Mining
Said of a mineral deposit formed by the process of mobilization of elements from a solid rock and their transportation and redeposition elsewhere. On a local scale, the process may be called a product of lateral secretion; on a larger scale, the deposit may be called a product of regional metamorphism.
Industry:Mining
Said of a mineral deposit in which the minerals fill the pores of the host rock. Compare: Frenkel defect; impregnated.
Industry:Mining
Said of a mineral deposit or enrichment formed near the surface, commonly by descending solutions; also, said of those solutions and of that environment. Compare: hypogene; mesogene.
Industry:Mining
Said of a mineral deposit or enrichment of mingled hypogene and supergene solutions; also, said of such solutions and environment. Compare: hypogene; supergene.
Industry:Mining
Said of a mineral displaying large spheroidal surfaces, e.g., malachite.
Industry:Mining
Said of a point group or of specific crystal forms in the isometric and tetragonal crystal systems that have but one-fourth the crystal faces generated for the equivalent crystal form in the holohedral (most symmetric) crystal class. These complimentary merohedral forms are designated plus or minus and left or right, four forms being required to show all the faces of the holohedral form because each form lacks both a center and mirror planes of symmetry.
Industry:Mining
Said of a porphyritic igneous rock having large phenocrysts in a glassy groundmass.
Industry:Mining
