Deciphering the magma storage conditions and preeruptive processes at Cumaçay: a Plio-Quaternary volcanic eruption center in Eastern Anatolia, Turkey

Turkish Journal of Earth Sciences

article

ÖZDEMİR, YAVUZ¹  ÖZDEMİR, AYHAN² 

[1] Department of Geological Engineering, Van-Yüzüncü Yıl University;Institute of Natural and Applied Sciences Van-Yüzüncü Yıl University

关键词: Eastern Anatolia;    magma plumbing system;    thermobarometry;    mineral chemistry;   

DOI  :  10.55730/1300-0985.1837

学科分类：地球科学(综合)

来源: Scientific and Technical Research Council of Turkey - TUBITAK

【 摘 要 】

We investigate the geology and petrology of Cumaçay, one of the Plio-Quaternary eruption centers of postcollisional volcanism in Eastern Turkey, using a combination of geochronology, bulk-rock geochemistry, thermobarometry, and thermodynamic simulations. Our new K-Ar ages reveal an age of 3.5-0.97 Ma for the eruptive products, which spread around an area of approximately 1000 km2. Mineral-melt equilibria for olivine, orthopyroxene, clinopyroxene, and plagioclase allow estimation of crystallization pressures, and temperatures indicate two separate crustal storage of crystallization at 14-28 km and 5-15 km. The temperature estimation from diverse methods ranges from 954 °C to 1224 °C. Thermodynamic modelings using Magma Chamber Simulator (MCS) at a representative pressure (5 kbar) imply that the assimilation and crustal contamination (AFC) resulted in evolved melts with various SiO2 contents at mid to lower crustal depths. Calculated wide range of temperatures, compositional variety from evolved members, and MCS recharge simulation at a representative pressure (2.5 kbar) reveal that the magma mixing between contrasted melts characterizes the final chemical dispersal of the erupted lavas.

【 授权许可】

Unknown