New zircon ages on the Cambrian–Ordovician volcanism of the Southern Gemericum basement (Western Carpathians, Slovakia): SHRIMP dating, geochemistry and provenance

• Published in: International journal of earth sciences : Geologische Rundschau 2017-09, Vol.106 (6), p.2147-2170
• Main Authors: Vozárová, Anna, Rodionov, Nickolay, Šarinová, Katarína, Presnyakov, Sergey
• Format: Article
• Language: English
• Subjects: Cambrian; Cores; Earth and Environmental Science; Earth Sciences; Fragments; Geochemistry; Geological time; Geology; Geophysics/Geodesy; Heredity; Melting; Mineral Resources; Niobium; Ordovician; Original Paper; Provenance; Quality; Radiometric dating; Rock; Sedimentary rocks; Sedimentology; Structural Geology; Subduction; Tantalum; Volcanic activity; Volcanism; Volcanoes; Zircon; Zirconium
• ISSN: 1437-3254; 1437-3262
• DOI: 10.1007/s00531-016-1420-2

The Southern Gemericum basement in the Inner Western Carpathians, composed of low-grade volcano-sedimentary rock complexes, constitutes a record of the polyphase Cambrian–Ordovician continental volcanic arc volcanism. These metavolcanic rocks are characterized by the enrichment in K, Rb, Ba, Th and Ce and Sm relative to Ta, Nb, Hf, Zr, Y and Yb that are the characteristic features for volcanic arc magmatites. The new SHRIMP U–Pb zircon data and compilation of previously published and re-evaluated zircon ages, contribute to a new constrain of the timing of the Cambrian–Ordovician volcanism that occurred between 496 and 447 Ma. The following peaks of the volcanic activity of the Southern Gemericum basement have been recognized: (a) mid-late Furongian at 492 Ma; (b) Tremadocian at 481 Ma; (c) Darriwilian at 464 Ma prolonged to 453 Ma within the early Upper Ordovician. The metavolcanic rocks are characterized by a high zircon inheritance, composed of Ediacaran (650–550 Ma), Tonian–Stenian (1.1–0.9 Ma), and, to a lesser extent, Mesoproterozoic (1.3 Ga), Paleoproterozoic (1.9 Ga) and Archaean assemblages (2.6 Ga). Based on the acquired zircon populations, it could be deduced that Cambrian–Ordovician arc crust was generated by a partial melting of Ediacaran basement in the subduction-related setting, into which old crustal fragments were incorporated. The ascertained zircon inheritances with Meso-, Paleoproterozoic and Archaean cores indicate the similarities with the Saharan Metacraton provenance.