Zespoły minerałów tlenkowych i ich znaczenie w odczytaniu genezy skał masywu suwalskiego
Abstract
ASSEMBLAGES OF OXIDE MINERALS AND THEIR IMPORTANCE FOR THE GENESIS OF ROCKS OF THE SUWAŁKI MASSIF (NE POLAND)
Summary
Three assemblages of oxide parageneses were distinguished in rocks of the Suwalki Massif: (1) magnetite with many outside phases, with ilvospinel, lenses of Mg-Fe spinels, secondary ilmenite lamellae and ilmenite with individual magnetite and Mg-Fe spinel lamellae as well as pleonaste characteristic of ores and ore norites; (2) magnetite with indyvidual ilmenite lamellae and Mg-Fe spinel lenses, and ilmenite without outside phases characteristic of monzonites, diorites, gabbro-norites and norites; (3) magnetite with individual ilmenite lamellae and ilmenite with individual magnetite and Fe-Mg spinel lamellae and many hematite lenses, characteristic of diorites and anorthosites as well as ore schlieren in anorthosites. These assemblages depend on temperature and oxygen pressure in magma and rocks. Modified geological thermometer of K.J. Spencer and D.H. Lindsley from 1981 indicates that the first assemblage was formed in temperature of minimum 720°C and in the lowest oxygen temperature, and the subsequent assemblages in the higher oxygen pressure and lower temperature. The history of alterations of oxide parageneses indicates the magmatic origin of the rocks studied.
Summary
Three assemblages of oxide parageneses were distinguished in rocks of the Suwalki Massif: (1) magnetite with many outside phases, with ilvospinel, lenses of Mg-Fe spinels, secondary ilmenite lamellae and ilmenite with individual magnetite and Mg-Fe spinel lamellae as well as pleonaste characteristic of ores and ore norites; (2) magnetite with indyvidual ilmenite lamellae and Mg-Fe spinel lenses, and ilmenite without outside phases characteristic of monzonites, diorites, gabbro-norites and norites; (3) magnetite with individual ilmenite lamellae and ilmenite with individual magnetite and Fe-Mg spinel lamellae and many hematite lenses, characteristic of diorites and anorthosites as well as ore schlieren in anorthosites. These assemblages depend on temperature and oxygen pressure in magma and rocks. Modified geological thermometer of K.J. Spencer and D.H. Lindsley from 1981 indicates that the first assemblage was formed in temperature of minimum 720°C and in the lowest oxygen temperature, and the subsequent assemblages in the higher oxygen pressure and lower temperature. The history of alterations of oxide parageneses indicates the magmatic origin of the rocks studied.