20.500.12556/DiRROS-31346 Geodynamic evolution of the Northernmost Dinarides revealed by the petrogenesis of Mid-Triassic calc-alkaline volcanic rocks This paper presents mineralogical, petrological, geochemical, and Sr–Nd isotopic data on volcanic rocks from the Northwestern Croatian Triassic Rift Basin, which is a locally aborted back-arc rift system of the Paleotethys. The dataset also includes their isotopic ages, along with the biostratigraphic ages of all interbedded sedimentary rocks. These volcano-sedimentary successions represent the northernmost parts of the Dinarides. The obtained 40Ar/39Ar isotopic age (243±1.8 Ma) indicates the Late Anisian age of the basaltic eruption and is somewhat consistent with the obtained Early Ladinian biostratigraphic ages of the interbedded sedimentary rocks. The initial εNd varies between −0.08 to +1.90, while the initial 87Sr/86Sr varies in a wide range from 0.704765 to 0.709248. The investigated Late Anisian to Early Ladinian calc-alkaline/shoshonitic basaltic lavas were formed through: (i) low-degree partial melting (5–14 %) of a shallow (spinel stability facies; max. depth ~33 km) magma source region in the subcontinental lithospheric mantle and (ii) fractional crystallisation in a partially open magmatic system. The magma generation also involved: (i) melts from the subducted slab, which is likely linked to the ancient, subducted oceanic crust of the Paleotethys, (ii) less abundant, previously subducted continental crustal material – sediments recycled in the mantle wedge, and (iii) a negligible contribution from depleted or an ocean-island, basalt-like mantle. These conditions suggest that the magma formed through a complex process during magma ascent through tectonically weakened crustal zones. Although the intense effusive volcanic activity during the Middle Triassic in the Northwestern Croatian Triassic Rift Basin lasted for a relatively short period (~3–4 Myr; Bithynian–Fassanian), its geodynamic evolution was complex and can be attributed to: (i) the subduction of the Paleotethyan lithosphere associated with an ensialic volcanic arc developed in an active continental margin setting, and (ii) the processes of continental rifting along the mid-Triassic margins of the Adria Plate, i.e., Greater Adria. These processes represent the beginning of rifting, which affected a greater area on the Balkan Peninsula as well. Middle Triassic calc-alkaline volcanism basalt suite northernmost segment of the Dinarides NW Croatia and E Slovenia true false true Angleški jezik Ni določen Neznano 2026-07-29 11:18:59 2026-07-29 11:18:59 2026-07-30 03:49:45 0000-00-00 00:00:00 2026 0 0 str. 307-329 no. 4 vol. 77 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-06-30 551.1/.4 1335-0552 10.31577/GeolCarp.2026.16 283202051 06300844GeolCarp_2026_307-329.pdf 06300844GeolCarp_2026_307-329.pdf 1 C76701C7D5F9B657432D6FA820EBEB0B b2a142395590812df9a15cf8bd86f267aee16861b38d5ad58829fd2ec2c5c74e ff1eb213-8b2e-11f1-923b-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=48488 06300844GC-77-4-Slovenec_FigsS1-S2.zip 06300844GC-77-4-Slovenec_FigsS1-S2.zip 1 49F92CE248BED5F1DF021A1FCC42DC94 04fdfdfc63b2b0bcc3a737d9bfa8f4c70708eaa044e0f6d66c413f65ea8f1a7f 5914c1ba-8b2f-11f1-923b-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=48489 06300844GC-77-4-Slovenec_TablesS1-S5.zip 06300844GC-77-4-Slovenec_TablesS1-S5.zip 1 8BCC4A8855CB07564E2582F62B3967AE 011a867deed611100316b649a0a3f1238f0e152ffaf177e68679821a22300409 6f57f624-8b2f-11f1-923b-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=48490 Geološki zavod Slovenije 0 0 0