Peri-Amazonian, Avalonian-type and Ganderian-type terranes in the South Carpathians, Romania: The Danubian domain basement

The Danubian domain basement of the South Carpathians, Romania, comprises two Neoproterozoic continental crustal fragments, the Drăgşan and Lainici-Păiuş terranes, which were sutured by the closure of an intervening oceanic domain, the Tişoviţa terrane. Magmatic and detrital zircons extracted from an orthogneiss, four granitoid plutons, two metasedimentary units, and a Liassic sandstone were dated by zircon U/Pb LA-ICP-MS. The Făgeţel augen gneiss from the Drăgşan terrane basement yielded an age of 803.2 ± 4.4 Ma, the oldest well-constrained crystallization age reported from the Romanian Carpathians basement. The Tismana, Şuşiţa, Novaci and Olteţ granitoid plutons, which intrude the Lainici-Păiuş terrane basement, yielded ages of 600.5 ± 4.4, 591.0 ± 3.5, 592.7 ± 4.9, and 588 ± 2.9 Ma, respectively. The Tismana granitoid age of 600 Ma and the youngest detrital zircon ages of 637–622 Ma from a metaquartzite within the Lainici-Paiuş terrane, constrain the deposition of the metaquartzite protolith to ca. 620–600 Ma. The 803 Ma age represents an old Pan-African age, whereas the younger Neoproterozoic ages suggest Pan-African/Cadomian thermotectonic events. Detrital and inherited zircon ages within the Drăgşan and Lainici-Paiuş terranes attest to a peri-Amazonian, Avalonian-type provenance for the Drăgşan terrane and possibly a Ganderian-type provenance for the Lainici-Păiuş terrane. The Lainici-Păiuş terrane rifted off Gondwana before the Drăgşan terrane. Both terranes were attached to Moesia during the Early Paleozoic.