Geologo

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Mining Terms
 
AGGLOMERATE: A chaotic assemblage of coarse angular volcaniclastic material extruded by a volcano.
ANDESITE: Dark, fine grained extrusive rock. Fine grained equivalent to diorite.
ANOMALY: a deviation from uniformity or regularity, a local feature distinguishable in geophysical or geochemical measurement.
BASALT: Dark coloredfine grained rock usually from volcanic origin.
BATHOLITH: A large, generally discordant igneous mass that penetrated the earth’s crust. It could be exposed over a large area or buried under overlaying rocks.
BRECIATED: Rock structure marked by an accumulation of angular fragments, or an ore texture showing mineral fragments without noticeable rounding.
CHLORITE: A platy mica mineral commonlyassociated with alteration of the rock minerals by hydrothermal activity.
CONCESSION (MINERAL CONCESSION): mineral rights given by the Government for mineral exploration or exploitation within a specific surface area regardless of surface ownership. In areas where the ground is covered under a Colombian “Reserva Forestal”, there has to be a “Sustraccion de Concesion” (removing the Reserva Forestaldesignation from the area covered by the concession) before any mining or mayor surface disturbance is made.
CRETACEOUS: The final period of the Mesozoic Era which covers the time span between 135 and 65 million years ago.
DEPARTMENT: A political administrative division of a country that has a central Unitarian government.
DEVELOPMENT: work carried out for the purpose of opening up a mineraldeposit and making the actual extraction possible.
DIABASE: a dark colored basic intrusive rock. Sometimes is used in the field when the exact composition of the rock cannot be determined. The main minerals forming the rock are pyroxenes.
DIORITE: medium grained, gray colored igneous rock (intrusive rocks cool within the earth’s crust, as opposed to extrusive, or volcanic, rocks which cool at theearth’s surface).
DIP: the angle at which a vein, structure or rock bed is inclined from the horizontal as measured at right angles to the strike.
DRIFT:  Term used to indicate underground opening developed along the length of a vein. 
ELECTRUM: A naturally occurring alloy of gold and silver (argentiferous gold) containing more than 20% silver.
EOCENE: an epoch of the Early Tertiary Period ofthe earth’s history from 55 to 38 Million years ago.
EPITHERMAL: term applied to hydrothermal deposition of mineral deposits within about one kilometer of the earth’s surface.
EXPLORATION: work involved in searching for ore by geological mapping, geochemistry, geophysics, drilling, and other methods.
FOOTWALL: the underside of a fault, ore body or mine working. It is the wall rock beneath aninclined vein or fault.
GEOSYNCLINE: A mobile down warping of the crust of the earth in a basin where volcanic and sedimentary rocks accumulate to thickness of thousands of meters.
GEOCHEMISTRY: study of relative and absolute abundances of chemical elements and atomic species (isotopes) in rocks, soils, water, or atmosphere.
GEOPHYSICS: study of the earth by quantitative physical methods.GRANODIORITE: coarse grained, grey colored igneous rock containing more quartz than the finer grained diorite.
GREENSTONE: a field term applied to any dark-green altered or metamorphosed basic igneous rock such as basalt or diabase.
HANGINGWALL: the upper side of a fault, ore body or mine working. It is the wall rock above an inclined vein or fault.
HECTARE: metric measure of area, equivalent to2.47105 acres or 0.003861 square miles.
HORNFELS: a fine grained rock composed of a mosaic of equidimensional grains without preferred orientation and typically formed by contact metamorphism.
HYDROTHERMAL: pertaining to hot water, especially with respect to its action in dissolving, re-depositing, and otherwise producing mineral changes within the earth’s crust.
IGNEOUS: refers to a rock or...