Petrographic and geochemical characteristics of metabasaltes of nappe Bork between Kobeliarovo and Vysna Slana

A short overview of the results of petrological and geochemical research of metabasaltes of several lithostratigraphic units of nappe Bork in NW part Spis-Gemer-Rudohorie Mountain is shown. This area is from a geological point of view typical by high-pressure-low temperature (HP/LT) metamorphism, represented by facies of blue shale with index mineral sodium amphibole - glaucophan. Rocks rich in glaucophan - glaucophanites are mostly formed at the expense of effusive basalt. It can be seen thanks to preserved relics intersertal or ofitic structure, but also the test results in the classification diagrams. Using a variety of discrimination diagrams we proved, that in pre-metamorphic form of HP/LT metamorphism is probably the result of tightening in subduction zone and for Hacava formation also the result of rapid exhumation. Metabasaltes of Kobeliarovo and Steinberg formations were exhumed more slowly, and consequently in their metamorphic evolution a retrograde metamorphosis into the green slate facies took place. Subduction and exhumation were associated with closing of Meliata Ocean in the Upper Jurassic (150-160 Ma). (authors)