Ewolucja mineralizacji kruszcowej związanej z procesem karbonatytyzacji w masywie Tajna

Abstract

Pierwotne minerały kruszcowe, do których należą: pirotyn, piryt, ilmenit, chalkopiryt, sfaleryt i galena, związane są genetycznie z matasomatozą alkaliczno-węglanową. W wyniku późniejszych przeobrażeń autometasomatycznych i hydrotermalnych powstały wtórne minerały i fazy mineralne: produkt prze obrażenia pirotynu jako pośrednia faza, mieszanina produktu pośredniego i uwodnionych tlenków żelaza. piryt, markasyt. magnetyt, hematyt, goethyt, lepidokrokit, chalkopiryt, bornit, digenit. kowelin. rutyl i leukoksen. Omówiono sekwencję procesów mineralizacji siarczkowo-tlenkowej. opisano cechy strukturalno-teksturalne zespołów mineralnych i porównano przeobrażenia z procesami opisanymi w wybranych pozycjach literatury. EVOLUTION OF THE ORE-MINERALIZATION, CONNECTED WITH THE CARBONATITIZATlON PROCESS IN THE TAJNO MASSIF Results from the Ore mineralization tests connected with carbonatites in the a1caline·ultrabasic massif of Tajno are presented. Primary Ore minerals such as pyrite, pyrrhotite, ilmenite, chalcopyrite, sphalerite, galena are genetically connected with the alkaline-carbonate metasomatosis subject to alternation. resulted in later autometasomatic and hydrothermal processes. Pyrrothite. of which a series of minerals and mineral phases developed, is subject to alternation in the highest degree. Decomposition of pyrrothite is iniciated with the intermediate phase (M.T. Einaudi, 1971) with optical characteristics aproximated ones of pyrite. with enducing of iron in a form of the hydrated ferric oxides mixtures. Re· crystallization of the intermediate phase goes next (metacrystals pyrite are forming) and a product of characteristics of magnetite originates from the hydrated ferric oxides. Sometime the pyrite metacrystals are subject to alternation into marcasite, forming lamellar texture intergrowing with sterile minerals. Magnetitc is subject to alternate into haematite in an unimportant degree, particularly on the sides of the grains. Then haematite is replaced by goethite and lepidocrocite. Pyrite of the first generation. forms in the first stage of carbonatitization (A. Dziedzic, W. Ryka, 1983) and also is subject to alternation into secondary ferric oxide of the goethite-lcpidocrocite-type. Characteristic assotiation is forming by groups of plates and slips with pyrrhotite, intermediate phase, pyrite, marcasite, and secondary ferric oxides. Cooper sulfides (chalcopyrite, bornite, digenite and covellite) occur in small numbers. they enter into the composition of groups built of products of the pyrrhotite decay. Chalcopyrite is a primary mineral. Sphalerite in two forms (marmatite and cleiophane) occurs in rather large numbers, and galena - occasionally.