Neoproterozoic continental arc magmatism along the northern Gondwanan Margin: Geochemistry and U–Pb geochronology of felsic intrusions from the eastern Taurides, Southern Turkey


YAPICI N., NURLU N., GÜNEYLİ H., Sonsun H., ÜRÜNVEREN A.

Journal of African Earth Sciences, cilt.231, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 231
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.jafrearsci.2025.105781
  • Dergi Adı: Journal of African Earth Sciences
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Geobase, INSPEC
  • Anahtar Kelimeler: Cadomian orogeny, Continental arc magmatism, Eastern Taurides, Subduction-related felsic intrusions, U–Pb zircon geochronology
  • Çukurova Üniversitesi Adresli: Evet

Özet

The Eastern Taurides of southern Turkey represent a critical segment of the peri-Gondwanan margin, yet their Neoproterozoic magmatic history remains largely unconstrained. This study presents the first integrated geochemical and geochronological dataset from felsic subvolcanic intrusions—including granodiorite porphyry, tonalite porphyry, microgranodiorite, and aplite dikes—that intrude the Precambrian metasedimentary rocks of the Oruçlu Formation. Field observations reveal polyphase magmatic emplacement with features such as chilled margins, stoped metasedimentary enclaves, and post-emplacement deformation, suggesting crystallization in a tectonically active arc setting. Whole-rock geochemistry indicates metaluminous, high-K calc-alkaline signatures with enrichment in LILEs (Rb, Th, U, Pb) and depletion in HFSEs (Nb, Ta, Ti), consistent with I-type granitoids derived from a subduction-modified mantle source. Low Sr/Y ratios and the absence of adakitic signatures point to magma genesis at moderate crustal depths without garnet residue, typical of continental arc systems. A U–Pb zircon crystallization age of 642.2 ± 7.5 Ma confirms emplacement during the early Cadomian orogeny, coinciding with the onset of Proto-Tethys Ocean subduction. The Horzum felsic intrusions show close geochemical similarities to other Ediacaran–Cambrian granitoids in the Bitlis Massif, NW Turkey, and Iran, supporting the existence of a regionally extensive, Andean-type continental arc system along the northern margin of Gondwana. These results contribute to bridging a key spatial and temporal gap in the Neoproterozoic magmatic record of the Eastern Mediterranean region and provide new constraints on crustal evolution along the peri-Gondwanan margin. Despite their limited exposure and volume, these intrusions provide critical new constraints on Cadomian magmatism in southern Turkey, and establish the northern Gondwanan margin as a key locus of Neoproterozoic crustal growth in the Eastern Mediterranean region.