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Late-Hercynian gold-bearing arsenic-polymetallic mineralization within Saxothuringian zone in the Polish Sudetes, Northeast Bohemian Massif
Published in Adam Piestrzyński, Mineral Deposits at the Beginning of the 21st Century, 2001
Gold-bearing sulphide mineralization occurs in different forms within quartz veins, lodes, and stockworks, or as replacement ore bodies, skarns and host rock impregnations. In Złoty Stok and Czarnów the ore-bodies are concordant with late stage high-angle NE-SW shears that occurred after emplacement of Variscan granitoids. In Klecza-Radomice and in Radzimowice deposits the ore-bearing quartz veins run parallel to W-E direction on brittle displacement on the Intra-Sudetic Fault. According to Aleksandrowski et al., (1997) this movement took place during the Upper Carboniferous – Lower Permian time. The major structural event of the Variscan evolution of the Sudetes was characterised by regional extension. The Czarnów deposit is located within the Leszczyniec shear zone that constitutes the eastern metamorphic cover of an S-type Karkonosze granite intrusion, dated at 328 ± 12 Ma (Pin et al., 1987). This deposit consists of a main quartz lode, enclosed by Lower Paleozoic calc-silicate rock with subordinate mica schist, dolomite intercalation with amphibolite that represent within-plate volcanic rocks. In Złoty Stok the metasomatic gold-bearing sulphide mineralization was due to processes in the exocontact zone of the I-type Variscan Kłodzko-Złoty Stok granodiorite massif. Younger gold-bearing stages (II and III) revealed cycles of brittle deformation and hydrothermal infill by mineralising fluids, connected with the development of the Skrzynka shear zone (Mikulski 1996). Host rocks are of blastomylonite, cataclasite, gneiss, schist and calc-silicate rocks of Lower Paleozoic age, intercalated with mafic and felsic metaintrusives and metavolcanics that underwent regional amphibolite facies metamorphism, thermally overprinted along the contact with the granitoid massif.
Lithostratigraphy of Paleozoic metasediments in southern Fiordland, New Zealand
Published in New Zealand Journal of Geology and Geophysics, 2023
Richard Jongens, Ian M. Turnbull, Andrew H. Allibone
Unfoliated to weakly foliated fine grained metasediments crop out between northeast-striking faults immediately north of the Hauroko Fault, southwest of Lake Poteriteri (Turnbull and Uruski 1995). They are dominated by interbedded psammite, pelite and calc-silicate rock, with rare marble, metachert, and amphibolite. Metamorphic minerals in the calc-silicate rock include diopside, indicating upper amphibolite facies temperatures. These metasediments are tentatively placed in the Cameron Group even though they are texturally finer grained.