Korgal pegmatite field (Korghal; Kurghal), Nuristan District, Nuristan Province (Nurestan Province; Nooristan Province; Nuristan), Afghanistan
|Latitude & Longitude (WGS84):||35° 4' 4'' North , 70° 18' 21'' East|
|Latitude & Longitude (decimal):||35.0677777778, 70.3058333333|
|Other regions containing this locality:||Asia|
The deposits consist of Cs-Rb-Li-Ta-Nb-rich pegmatite veins, embedded in proterozoic crystalline schist and garnet-sillimanite-biotite gneiss (Bariand & Poullen 1978). Individual veins are hundreds of meters long and up to 50 m thick. The Kurghal pegmatite, for which the field is named, was mined for some time around 1995. Among other species, it produced green tourmaline (Orris & Bliss, 2002).
The grid reference is centered on the field.
|Proterozoic541 - 2500 Ma||Proterozoic intrusive and metamorphic terranes|
Intrusive and metamorphic terranes
Mixtures of metamorphic and intrusive or plutonic rocks, tracts known as crystalline, migmatitic terranes, moderately to highly metamorphosed rocks of unknown origin with or without intrusions. This classification is inherently prone to variable interpretation, as other compilers might distinguish some packages by their metamorphic or gneissic protoliths, and the associated age ranges may be more variable.
|Siderian2300 - 2500 Ma||Early Paleoproterozoic gneiss|
Early Paleoproterozoic two-mica, biotite, biotite-amphibole, garnet-biotite, garnet-sillimanite-biotite, pyroxene-amphibole, plagiocalse, and cordierite gneiss; schist, migmatite, quartzite, marble, amphibolite.
References for regional geology:
Data provided by Macrostrat.org
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
Doebrich, J.L., R.R. Wahl et al. Geologic and mineral resource map of Afghanistan. isbn: 9781411318038. USGS Open-File Report 2006-1038.
12 valid minerals.
Orris, G.J., and Bliss, J.D. (2002): Mines and Mineral Occurrences of Afghanistan. United States Geological Survey Open-File Report 02-110.