The character of upper mantle/lower crust beneath the Bohemian Massif based on geochemical signatures of (ultra)mafic xenoliths in Cenozoic volcanics

The distribution of upper mantle and deep crustal (ultra)mafic xenoliths in Cenozoic volcanics of the Bohemian Massif (BM) will be studied with special reference to compositional and textural variations and metasomatic effects in the upper mantle. The model occurrences selected for each rock type/association of xenoliths during a pilot study will reflect different positions within the taphrogenic structures of the BM. Geochemical data will be used for modelling of PTX conditions of the crystallization of xenoliths and the host rocks. Their subsequent thermal history will be determined using the fission tracks method. From the data obtained, depths of their origin will be estimated, and different genetic models will be formulated to explain the genesis of xenolith associations in different areas of the BM and at different positions within taphrogenic structures. These results will be combined with geophysical data (e.g., BOHEMA project) to model the deep structure of the Ohře Rift.