@ARTICLE{Birkenmajer_Krzysztof_Late_1992, author={Birkenmajer, Krzysztof and Frankiewicz, Jerzy K. and Wagner, Marian}, volume={vol. 13}, number={No 2}, journal={Polish Polar Research}, pages={71-90}, howpublished={online}, year={1992}, publisher={Polish Academy of Sciences}, publisher={Committee on Polar Research}, abstract={Anthracite coal matter fills irregular voids in dolostones of the Upper Proterozoic Höferpynten Formation in the Hornsund area, south Spitsbergen. The coals are of organic origin, as indicated by a variety of coal-petrographic studies, and by association with algal structures. They probably derived from bitumina accumulated in voids of dolostone at an early diagenelic stage. The degree of coalification (graphitization) is high but diversified, suggesting several coalification stages, probably related t o successive metamorphic events. The oldest changes may correspond to initial stage of t h e greenschist-amphibolite phase of regional metamorphism, with temperatures of over 500°C and pressure of over 20,000 MPa . Multiphase graphite crystallites which occur in t h e coal are mainly fibrous. There are also crystallites which precipitated from gaseous phase, and pyrolitic graphite; they may have originated due to action of mesothermal solutions which had produced ore-bearing veins.}, type={Article}, title={Late Proterozoic anthracite coals from the Hornsund area, south Spitsbergen}, URL={http://www.journals.pan.pl/Content/111082/PDF-MASTER/1992-2_071-090.pdf}, keywords={Arctic, Spitsbergen, Late Proterozoic, anthracite coal}, }