pgs.+643-647+notes

=**Mineral Resources and Igneous Processes**= =Mineral Resources and Metamorphic Processes= =Weathering and Ore Deposits=
 * most important accumulations of metals produced by igneous processes
 * mineral resources result from processes that concentrate desirable materials to the extent that extraction is economically feasible
 * Magmatic Segregation**
 * igneous processes that generate metal deposits are straight forward
 * magmatic segregation is important in late stages of the magnetic process
 * **pegmatites-** very course-grained igneous rock, typically granite
 * Diamonds**
 * important mineral with an igneous origin
 * used extensively as abrasives
 * originate at depths of nearly 200km
 * Hydrothermal Solutions**
 * hot watery solution that escapes from a mass of magma during the latter stages of crystalliztion
 * **vein deposits**- a mineral filling a fracture or fault in a host rock
 * **disseminated deposit-** any economic mineral deposit in which the desired mineral occurs as scattered particles in the rock but in sufficient quantity to make the deposit an ore
 * role of metamorphism in producing mineral deposits is frequently tied to igneous processes
 * extent to which host rock is altered depends on the nature of the intruding igneous mass as well as the nature of the host rock
 * resistant materials may show very little alteration
 * most common metallic mineral associated with metamorphism are zinc, lea, copper, iron
 * regional metamorphism can also generate useful mineral deposits
 * weathering creates many important mineral deposits by concentration minor amounts of metals that are scattered through unweathered rock into economically valuable concentrations
 * **secondary enrichment-** concentration of minor amounts of metals that are scattered through unweathered rock into economically valuable concentrations by weathering processes