Highly siderophile element and Os isotope systematics of the Cenozoic volcanic rocks from the Eastern Pontides, NE Turkey: Constraints on the origin and evolution of subcontinental mantle-derived magmas

Arslan M., Temizel İ., Ackerman L., Yücel C., Yazar E. A.

LITHOS, cilt.410-411, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 410-411
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1016/j.lithos.2021.106575
  • Dergi Adı: LITHOS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), Chemical Abstracts Core, Geobase, INSPEC, Pollution Abstracts
  • Anahtar Kelimeler: Highly siderophile elements, Platinum group elements, Osmium isotopes, Basalt, Cenozoic volcanic rocks, NE Turkey, PLATINUM-GROUP ELEMENTS, CHALCOPHILE METAL VARIATIONS, SULFIDE SATURATION HISTORY, SPINEL PERIDOTITE XENOLITHS, RE-OS, LITHOSPHERIC MANTLE, OSMIUM ISOTOPE, CRUSTAL CONTAMINATION, INTRAPLATE BASALTS, WEST GREENLAND
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

The Cenozoic subalkaline to alkaline volcanic rocks from the Eastern Pontides Orogenic Belt (EPOB) in NE Turkey exhibit wide range of highly siderophile element (HSE) contents and Os isotope compositions that can be related to their mantle sources and parental melt evolution. Although some Eocene rocks show signs of late-stage modification, most of the studied volcanic rocks possess primary HSE and Os systematics. The Eocene volcanic rocks have largely variable Pd-N/Ir-N (similar to 0.25-751), Pd-N/Pt-N (similar to 0.25-87) and (Os-187/Os-188)i ratios (similar to 0.113 to 0.51). The Miocene volcanic rocks have high Pd-N/Ir-N (similar to 2.6-441), low PdN/PtN (similar to 0.11-1.7) and radiogenic (Os-187/Os-188)(i) ratios ranging from-0.166 to 0.52 while the Mio-Pliocene volcanic rocks show high Pd-N/Ir-N of-7.2-29, low PdN/PtN (similar to 1.2-2.7), and only mildly radiogenic (Os-187/Os-188)i values between similar to 0.132 and 0.177. Finally, the Quaternary volcanic rocks have low Pd-N/Ir-N (similar to 2.3-3.6), PdN/PtN (similar to 0.9-1.6) and radiogenic (Os-187/Os-188)(i) values ranging from similar to 0.133 to 0.194. Overall, the primitive mantle-normalized HSE patterns of the studied volcanic rocks are characterized by PPGE (Pt, Pd) and Re enrichment with respect to IPGE (Os, Ir, Ru). The variations in HSE and radiogenic Os isotope compositions of the relatively differentiated volcanic rocks indicate that crustal assimilation played active role in their parental melt evolution, especially in the Eocene and Miocene period. Besides, the obtained HSE data also suggest that the parental magmas of all the studied volcanic rocks were generated mainly in the S-saturated conditions. The temporal and spatial HSE and Os isotope variations observed in the studied Cenozoic volcanic rocks reflect the heterogeneity of the mantle source beneath the EPOB, which could be attributed to variations in response of different fluid/melt metasomatism of the underlying SCLM.