Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Petrology of crystalline rocksin the geothermal borehole GTPV-LT1 in Litoměřice
Abstract
Exploratory well GTPV-LT1 was drilled in the North Bohemian town Litoměřice during 2006-2007 and reached the depth of 2110 m. The well penetrated Upper Cretaceous and Permo-Carboniferous complexes including ignimbrite of rhyolite composition at the base of Carboniferous at depths 780-910 m. The base of sedimentary complexes lies at depth 910-940 m. The basement (below ca 940 m) is composed of monotonous metamorphic complex dominated by mica schist rich in garnet, staurolite and kyanite. The garnet in the schist shows two-stage growth with Ca-poor garnet I, which is overgrown by skeletal rims of Ca-richer garnet II. Mineral assemblages, chemical composition of rock-forming minerals and characteristic two-stage zoning of garnet indicate that the crystalline rocks studied belong to the Teplá Crystalline Complex (NW edge of Bohemian terrane).
