Abstract
Cenozoic anorogenic volcanism of the Bohemian Massif is an integral part of the Central European Volcanic Province. Three main volcanic periods can be distinguished based on K-Ar data and known paleostress fields: (i) pre-rift (79-49 Ma), (ii) syn-rift (42-16 Ma) and (iii) late-rift (16-0.3 Ma), with the youngest period further subdivided into three episodes.
The dominant mafic rock types of all periods are of nephelinite - basanite / tephrite composition. The exceptions are suites of ultramafic rocks of the pre-rift period and of the final episode of the late-rift period.
The most voluminous are volcanic rocks of the syn-rift period occurring in the Ohře Rift Graben. The initial Sr-Nd ratios of the mafic volcanic rocks of the Bohemian Massif are characteristic of magmas derived from a sub-lithospheric mantle source.
The isotopic ratios resemble those of the HIMU mantle source.