Petrography and geochemistry of granitoids and related rocks from the pre-Neogene basement of the Slavonia-Srijem Depression (Croatia)

The pre-Neogene basement of the Slavonia-Srijem Depression (eastern Croatia) is composed various types igneous, metamorphic and sedimentary rocks. Here we present petrography geochemistry a heterogenous group represented by two alkali granite, syenite, rhyolite orthogneiss. granite type 1 has an A-type geochemical affinity: ferroan character, high content, concentration rare earth elements (REE3+), Rb, Zr, Nb Y, low CaO, MgO, P2O5, Ba, Sr Eu contents. syenite similar characteristics, but displays enrichment in K, which could be consequence feldspar zircon accumulation. 2 differs from having lower K2O accompanied higher Na2O concentrations, possibly resulting alteration or different parental magma/evolutionary process. are distinguished both their magnesian Y less pronounced negative anomaly, as well LREE/HREE. orthogneiss differences major element chemistry compared to 1, trace REE patterns. granites characterized Y/Nb<1.2, indicating ocean island basalt-like source, while originated melting crustal, probably metasedimentary source. belong Late Cretaceous magmatism Sava Zone, significantly Zone other rocks investigated this study.