Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi

Yazarlar: Simge OĞUZ SAKA, Faruk AYDIN

Konular:Mühendislik

DOI:10.28948/ngumuh.502235

Anahtar Kelimeler:NE Turkey,Late Cretaceous,Volcanism,Mineral chemistry,Geothermobarometry

Özet:    Late Cretaceous volcanic activity of the eastern Sakarya Zone (NE Turkey) that formed in two different periods (Turonian-Santonian and Late Santonian-Middle Campanian) is represented by large volume of mafic (basaltic to basaltic andesitic) and felsic (dacitic to rhyolitic) rock series  within each period. Previous studies indicate that metasomatized lithospheric mantle is suggested to be the source of the mafic volcanics whereas the mantle-derived differentiated basaltic melts which experienced with some magmatic processes are suggested to be the parent melt of the felsic rocks. However, there is no any evidence for crystallization conditions and depths of these mafic and felsic magmas formed in two different periods. To answer this question, we have used phenocryst compositions and some thermobarometric calculations to determine the P-T-D conditions of the magma reservoirs where crystallization occurred, then have used these data to reconstruct the magma plumbing system. Geothermobarometric investigation based on mineral chemistry of the main phases suggests that the late Cretaceous mafic and felsic magmas underwent a polybaric evolution history (~5.2-0.6 kbar), with crystallization processes occurring at different depths (~16-2 km) of the crust shortly before their eruptions.

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