engleski

Geochemistry and Petrology of Granitoids of Papuk and Psunj Mts. (Slavonia, Croatia)

Mineral composition, textural and structural features, chemical and isotopic characteristics of granitoid samples from different localities from Mt. Papuk and Mt. Psunj in Croatia were studied with the aim of their classification, identification of the magma composition, sources processes of their formation and plate tectonic settings. The main types of related gneisses and pegmatites were considered as well to better understand the relationships to the studied granitoids. The studied granitoids of Papuk and Psunj Mts. are monzogranite, granodiorite and quartz diorite. The granitoids from the Papuk Mt. divided into two-mica granitoids and K-feldspar porphyritic granitoids according to the mineralogical and also geochemical features. Two-mica granitoids have eutectic composition, mainly peraluminous character, A/CNK value equal or higher than 1.1 and correspond to the syn-collision granitoids according to Batchelor & Bowden (1985). K-feldspar porphyritic biotite monzogranite and granodiorite have transitional peraluminous to metaluminous character, A/CNK value equal or lower than 1.1 and were probably formed in post-collision uplifted environment. A/CNK molar ratio indicates mixed S/I-type origin. Granitoids from Omanovac Quarry are ferrohornblende-bearing monzogranites while the quartz diorite from the transition zone between Papuk and Krndija Mts. probably corresponds to the older granitoids occurring in Krndija Mt. The two-mica monzogranites contain maximum microcline and porphyritic ones, intermediate microcline and orthoclase as well. Pegmatite like, K-feldspar vein and pocket forming megacrysts are near maximum microcline, characterised by the absence of twinning and nonperthitic appearance of albite in the microcline host. Consequently, these K-feldspars are not pegmatitic, but precipitated from solution at low temperature. Two-mica monzogranite type was crystallised at minimum 11 km depth based on the high TiO2 content of muscovite (Miller et al., 1981), while amphibole-bearing monzogranite from Psunj Mt. was crystallised at around 2.5 kbars pressure and 740°C temperature. Appearance of primary epidote and zoned plagioclase in quartz diorite suggest higher crystallisation level and I-type origin. Correlation with the granitoids in the neighbouring areas showed that the studied granitoids from the Papuk and the Psunj Mts. have similar geochemical features with granitoids from the West Carpathians and Velence Mts. and they are supposed to have been part of the Inner Carpathian unit (Late Paleozoic and Triassic). Separation from the margin of the European Plane and significant counter-clockwise rotation led to the present position in the Tisza Megaunit.

Croatia; Papuk Mt.; Psunj Mt.; granitoids; K-feldspars; S/I-type; tectonic environment; comparison/correlation

Rješenje o priznanju inozemne visokoškolske kvalifikacije, akademski stupanj doktor prirodnih znanosti - geologija, od strane MZOŠ RH, Agencija za znanost i visoko obrazovanje, Zagreb, 26.05.2006.