Suchergebnisse

We present first data on the composition of melt inclusions in plagioclase and quartz crustal clasts and detailed study of plagioclase chemical zoning and mineral compositions from Bakhchysarai Late Albian tuffites. All magmatic melt compositions fall into field of high-K rhyolites. Measured water content in melt inclusions is up to 4 wt.%. Phenocrysts crystallized at the temperature within range 820-860 °C and pressure not less than 1 kbar. Bakhchysarai tuffites were formed in active continental margin geotectonical settings.

At least two outcrops of igneous rocks have been reported from the watershed of the Bodrak and Alma rivers (south-western Crimea). Previous studies suggested that these are intermediate to acidic volcanic rocks of pre-Middle Jurassic age. We compared the rocks from one of these outcrops with those from the near-contact area of the Middle Jurassic Dzhidairskiy intrusion, which is located proximally and predominantly consists of mainly of altered dolerites. It was determined found that the rocks from both locations were significantly altered as a result of the processes of acid metasomatism, down to quartz-carbonate-dikkite metasomatites. In this case, the nature of the changes and the appearance features of relatively unaffected by this metasomatism samples the most unaltered samples represented by altered dolerites are of the same type in both locations.