Geologia Croatica, Vol. 75 No. 1, 2022.
Izvorni znanstveni članak
https://doi.org/10.4154/gc.2022.09
Petrography and geochemistry of granitoids and related rocks from the pre-Neogene basement of the Slavonia-Srijem Depression (Croatia)
Sanja Šuica
orcid.org/0000-0002-0278-7762
; INA-Industrija nafte d.d., Zagreb, Croatia
Vesnica Garašić
; Faculty of Mining Geology and Petroleum Engineering, University of Zagreb, Croatia
Alan B. Woodland
; Goethe Universität Frankfurt, Institut für Geowissenschaften, Frankfurt, Germany
Sažetak
The pre-Neogene basement of the Slavonia-Srijem Depression (eastern Croatia) is composed of various types of igneous, metamorphic and sedimentary rocks. Here we present the petrography and geochemistry of a heterogenous group represented by two types of alkali granite, granite, syenite, rhyolite and orthogneiss. The alkali granite type 1 has an A-type geochemical affinity: a ferroan character, high alkali content, high concentration of rare earth elements (REE3+), Rb, Zr, Nb and Y, and low CaO, MgO, P2O5, Ba, Sr and Eu contents. The syenite has similar characteristics, but displays enrichment in Ba, K, Eu and Zr, which could be a consequence of feldspar and zircon accumulation. The alkali granite type 2 is an A-type granite but differs from the alkali granite type 1 in having lower K2O and Rb, accompanied by higher Na2O and Sr concentrations, possibly resulting from alteration or a different parental magma/evolutionary process. The granite and rhyolite are distinguished from both types of alkali granite by their magnesian character, lower Zr, Nb and Y concentrations, less pronounced Eu negative anomaly, as well as higher Ba, Sr and LREE/HREE. The orthogneiss displays differences in major element chemistry compared to the alkali granite type 1, but has similar trace element and REE patterns. The alkali granites are characterized by Y/Nb<1.2, indicating an ocean island basalt-like source, while the granite originated from melting of a crustal, probably metasedimentary source. The A-type granites could belong to the Late Cretaceous A-type magmatism of the Sava Zone, while the granite is significantly different from the Sava Zone A-type granites as well as the other rocks investigated in this study.
Ključne riječi
A-type granite; pre-Neogene basement; Slavonia-Srijem Depression; Sava Zone
Hrčak ID:
273375
URI
Datum izdavanja:
28.2.2022.
Posjeta: 510 *