The Staré mesto granite: its dating and genetic implications for the Variscan magmatism of the Western Carpathians

Detailed research on a small, isolated granite body, the so-called the Staré mesto granite (SMG), has yielded different information than are known from the main body of the Bratislava massif (Malé Karpaty Mts. in Western Carpathians, Slovakia). The SMG with a known gold mineralization is exposed as a small, elongated granite body hosted within the biotite gneisses of the Pezinok Group that are missing in the main Bratislava granite massif, because of a deeper erosion level. The high-potassium content, peraluminous and magnesium character of studied SMG granites are analogous to the evolved felsic members of the main granitic body. However, new dating results, i.e., a zircon U–Th–Pb isotopic age of 363.5 ± 2.1 Ma and a monazite chemical Th–U–Pb age of 360.7 ± 2.8 Ma are different from the magmatic age of ca. 355–353 Ma determined for the main granite body of the Bratislava massif. It is suggested that melting of the SMG granite source occurred during the initial stage of the Variscan continental collision before ca. 360 Ma, while the main granitic body of the Bratislava Massif was formed in the course of the late-collision granite flare-up before ca. 355–353 Ma.