Rodingitation of Diabase Dikes in the Ophiolitic Units of Eastern Lake Van Region: Ca-Metasomatism Processes Van Gölü Doğusu Ofiyolitik Birimlerinde Diyabaz Dayklarının Rodenjitleşmesi: Ca-Metasomatizma Süreçleri
Yerbilimleri/ Earth Sciences, cilt.46, sa.3, ss.129-148, 2025 (Scopus, TRDizin)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 46 Sayı: 3
- Basım Tarihi: 2025
- Doi Numarası: 10.17824/yerbilimleri.1737790
- Dergi Adı: Yerbilimleri/ Earth Sciences
- Derginin Tarandığı İndeksler: Scopus, Geobase, TR DİZİN (ULAKBİM)
- Sayfa Sayıları: ss.129-148
- Anahtar Kelimeler: ACF diagram, Eastern Anatolia, Isocron, Metasomatism, Rodingite
- Van Yüzüncü Yıl Üniversitesi Adresli: Evet
Özet
This study investigates the mineralogical, petrographic, and geochemical characteristics of rodenjites formed through the interaction of diabase dykes with Ca-rich hydrothermal fluids within serpentinized ophiolitic units east of Lake Van. Field observations and petrographic analyses revealed that the rodenjites are characterized by mineral assemblages dominated by epidote, grossular-type garnet, chlorite, vesuvianite, prehnite, and calcite. XRD data indicate the formation of epidote-clinozoisite, chlorite, garnet, and probable actinolite phases during rodenjitization. Geochemical analyses show that, compared to the diabase protoliths, the rodenjites exhibit significantly higher contents of CaO, Fe2O3, and MgO, along with notable depletions in SiO2, Al2O3, Na2O, and K2O. Enrichments in Sr (~480 ppm) and Ba (~230 ppm) provide valuable insights into the composition of the metasomatic fluids. Isocon diagram analysis indicates an approximate 12.4% mass loss during metasomatic alteration. The positioning of the samples on the ACF diagram closely resembles that of Othris-type rodenjites from Greece, suggesting that these processes are governed by universal geochemical mechanisms. Overall the findings demonstrate that the rodenjites formed through an open-system metasomatic transformation of diabase dykes by Ca-rich hydrothermal fluids, representing a typical example of metasomatic processes within ophiolitic belts. This process also reflects the complex tectonic and geodynamic evolution of Eastern Anatolia.