- 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 ...
Said of igneous rocks containing roughly equal amounts of felsic and mafic minerals, color index 40 to 70.
Industry:Mining
Said of igneous rocks having similar chemical composition but different mineralogic composition.
Industry:Mining
Said of igneous rocks in which the molecular proportion of alumina exceeds that of soda, potash, and lime combined.
Industry:Mining
Said of igneous rocks in which the molecular proportion of alumina is less than that of soda and potash combined.
Industry:Mining
Said of igneous rocks that consist of 90% to 100% mafic minerals. Compare: melanocratic; ultramafic.
Industry:Mining
Said of igneous rocks that have a common set of chemical and mineralogic features, and thus are regarded as having been derived from a common parent magma.
Industry:Mining
Said of large particles in a sedimentary rock that are not in contact with each other and are contained in a fine-grained matrix; e.g., quartz grains disseminated in limestone.
Industry:Mining
Said of layered material that exists or is introduced between layers of a different character; esp. said of relatively thin strata of one kind of material that alternates with thicker strata of some other kind, such as beds of shale intercalated in a body of sandstone. Compare: interbedded
Industry:Mining
Said of layered silicates having two-thirds of the voids in the octahedral layer filled, generally with trivalent cations. Compare: trioctahedral
Industry:Mining
Said of lead or copper ore that contains precious metals (gold and silver) but insufficient lead or copper to be smelted without the addition of richer ore.
Industry:Mining
