Cenozoic flare-up in the Eastern Iran magmatic belt: the dynamic link between closure of the Neotethyan ocean and magmatic events in the Lut Block


Raeisi D., Babazadeh S., Santosh M., Zhao M., Chiaradia M., SHAFAEİ MOGHADDAM H., ...Daha Fazla

International Geology Review, cilt.68, sa.2, ss.109-136, 2026 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 68 Sayı: 2
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1080/00206814.2025.2578453
  • Dergi Adı: International Geology Review
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Geobase
  • Sayfa Sayıları: ss.109-136
  • Anahtar Kelimeler: Eastern Iran magmatic belt (EIMB), Lut Block, Magmatic flare-up, Neotethyan Ocean, Roll-back
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

In this study, we focus on the Cenozoic magmatic suites in the Lut Block, a segment of the EIMB. The investigated plutonic rocks in the Lut Block, ranging in age from 47 to 37 Ma, encompass a wide compositional range from mafic to felsic, displaying medium to high-K calc-alkaline affinities. Epsilon Nd values in the investigated rocks range between −2.8 and +2.8, and the initial Sr isotope ratios is constrained to 0.7045‒0.7065. The age-corrected Pb isotopic compositions display ratios of2 0 6 Pb/2 0 4 Pb between 18.01 and 18.46, 2 0 7 Pb/2 0 4 Pb from 15.49 to 15.57, and2 0 8 Pb/2 0 4 Pb ranging from 38.19 to 38.47. Isotopic–incompatible trace elements modelling reveals the contribution of up to 2.5% sediment-derived melt and approximately 7% to as little as 2% assimilation of continental crust. A broader perspective on the Lut Block geochronological–isotopic data reveals a transitional shift in magmatism from the eastern (e.g. Bajestan; ~ 82 Ma) to the western (e.g. NW Gonabad, Gazu, Kajeh, and Vaghi; ~80 Ma to ~60 Ma) segments, peaking in magmatism during ~45 to ~38 Ma. This shift in magmatism may be associated with a change in the subduction mechanism of the Neo-Tethyan slab beneath Central Iran, transitioning from a low-angle dip to a higher dip following slab roll-back and the tilting of the lithospheric mantle along Eastern Iran. We hypothesize partial melting of phlogopite-bearing mantle sources metasomatized by sediment melts within the pre-collisional tectonic context, contributing to the widespread Eocene high-K magmatism throughout the Lut Block.