It is the reason, why geologists during last decades are concentrated on blueschist problem. Such pt conditions operate in zones of subduction, in which heavy oceanic lithosphere is mooving in the direction below the lighter continental lithosphere.īy thish way blueschist occurrences indicate very important processes in geological history. In both cases plagioclases are secondary altered.īlueschist glaucophane schist Glaucophane schists, based on their origin, represent unique rock type, which originated under very characteristic pt conditions: under high pressure and relativelly low temperature. Amphiboles from the other axe are lightgreen. For the artefact from the Velká Lomnica site bluishgreen colour in optical gama direction of amphibole is typical. Within the studied set of artefacts we found two made from amphibolites.

internetová zoznamka mužov v Trebišov Slovensko.Īmphibolites belong to often occurring rock types within the pre-cambrian and Paleozoic rock complexes, even the size of individual rock bodies is mostly small decametres and only rarely till hectometres thicknesses.

Characteristic is mostly well developed foliation and finetill medium grained character mm.

They are composed of basic plagioclases and monoclinic Ca green amphiboles.

Another area of antigorite serpentinite occurrences are Western Sudetes on the Polish territory Amphibolite Amphibolites are metamorphic rocks of medium- till high-grade metamorphic recrystallization of original rocks, to which namely basic eruptives belong. By their size we rank them among the very small till small decametres till hectometres dimensíons bodies. They are known also from the gemeric unit Paleozoic Bukovec, Vyšný Klátov, Dobšiná - Tešnárky. In the Western Carpathians they are known from the northem veporic unit located southward of the Hron river in its upper valley. ln the thin section studied the presence of coarse-flaky pseudomorphs after clinopyroxenes is detectable.īodies of antigorite serpentinites occur in complexes of metamorphic rocks. Antigorite serpentinite of discussed artefact is fine-grained, monomineralic with characteristic magnetite pigment. Massive homogeneous character of antigorite serpentinite together with its fine-grained character are the main factors of good technical properties of antigorite serpentinite used as raw material of Neolithic tools.

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