Mineraloška i geokemijska studija metamorfnih stijena u okolici volframsko–zlatonosnog ležišta Blagojev Kamen, Srbija : diplomski rad

Fourteen samples of metamorphic rocks were collected in the vicinity of Blagojev Kamen in East Serbia with the main goal to determine mineralogical and petrological characteristics of the rocks. The area belongs to East Serbian Carpatho Balkanides, a part of the orogenic belt that stretches through Romania, Serbia and Bulgaria, and curves around the Moesian Platform. The mineral composition of metamorphic rocks was determined by polarisation microscopy and chemical composition by mass spectrometry and atomic emission spectrometry (ICP–MS and ICP–AES). According to their petrographic characteristics, rocks were determined as hornfels and schists. The cordierite–quartz–epidote–chlorite–actinolite hornfels was formed by contact–metamorphism related to Variscan granitoids which intruded the metamorphic basement of Kučaj terrane near the sampling location. The rest of the rocks belong to low and medium grade Barrovian mineral assemblages, characterized by zonal distribution of the index–minerals: chlorite, epidote, biotite, amphibole and garnet. The observed Barrovian metamorphic sequence was compared to the regional Barrovian metamorphism of the northern part of Tisza–Dacia Mega Unit where it borders with Moesian Platform. Using the major, minor and trace elements data precursors and geotectonic environment of protolith formation were determined. Albite–epidote–chlorite–amphibole schist, epidote–chlorite–feldspar–amphibole schist and chlorite–epidote–albite–amphibole schist originate from basalt andesite or subalkaline basalt and garnet–quartz–chlorite–amphibole–albite schist originates from andesite. Albite–epidote–chlorite–amphibole schist, epidote–chlorite–feldspar–amphibole schist and chlorite–epidote–albite–amphibole schist show characteristics of normal to enriched MORB. Garnet–quartz–chlorite–amphibole–albite schist shows characteristics of volcanic arc basalts and within plate tholeiites to calc–alkaline basalts.Četrnaest uzoraka metamorfnih stijena prikupljeno je u okolici Blagojevog Kamena u istočnoj Srbiji, s glavnim ciljem odredbe mineraloških i petroloških značajki stijena. Područje pripada Istočno Srpskim Karpato–balkanidima, dijelu orogenskog pojasa koji se prostire kroz Rumunjsku, Srbiju i Bugarsku, a okružuje Mezijsku platformu. Polarizacijskom mikroskopijom utvrđen je mineralni sastav metamorfnih stijena, a kombinacijom masene spektrometrije i atomske emisijske spektrometrije (ICP–MS i ICP–AES) određen je kemijski sastav stijena. Prema svojim petrografskim karakteristikama, stijene su određene kao hornfels i škriljavci. Kordijerit–kvarc–epidote–klorit–aktinolitski hornfels nastao je kontaktnim metamorfizmom vezanim uz intruzije variscijskih granitoida koji su intrudirali u metamorfnu podlogu Kučaj terena u blizini mjesta uzorkovanja. Ostatak stijena pripada Barrow–vljevoj metamorfnoj sekvenci niskog i srednjeg stupnja, koje karakterizira zonalni raspored indeks–minerala: klorit, epidot, biotit, amfibol i granat. Uočeni metamorfni slijed Barrow–vljevog tipa uspoređen je s regionalnim Barrow–vljevim metamorfizmom na sjevernom dijelu mega jedinice Tisza–Dacia gdje graniči s Mezijskom platformom. Koristeći podatke o glavnim, sporednim i elementima u tragovima moguće je odrediti protolite i tektonski smještaj nastanka protolita. Albit–epidot–klorit–amfibolski škriljavac, epidot–klorit–feldspat–amfibolski škriljavac i klorit–epidot–albit–amfibolski škriljavac nastali su iz bazalta odnosno andezita ili subalkalnog bazalta, a granat–kvarc–klorit–amfibol–albitski škriljavac iz andezita. Albit–epidot–klorit–amfibolski škriljavac, epidot–klorit–feldspat–amfibolski škriljavac i klorit–epidot–albit–amfibolski škriljavac nastaju iz normalnih do blago obogaćenih bazalta srednjeoceanskih hrptova. Granat–kvarc–klorit–amfibol–albitski škriljavac nastaje iz protolita koji pokazuje svojstva bazalta vulkanskog luka i toleita unutar ploča do kalc–alkalnih bazalta