Quaternary Volcanic Activity in the Greater Caucasus: A Review of Elbrus, Kazbek and Keli Volcanoes

摘要

Our work provides as review of Quaternary volcanic activity in the Greater Caucasus. In particular, we have focused our attention on the Elbrus (northern slope of the main range of the Greater Caucasus), Kazbek (central sector of the Greater Caucasus) and Keli (southern slope of the main range of the Greater Caucasus) volcanoes. After conducting detailed isotope-geochronological, geological and petrological-mineralogical studies regarding the above volcanic centres, we have been able to document multiple phases of volcanic activity: ⅰ) five phases have been defined for the Elbrus volcanic centre: Ⅰ - 950-900 ka (andesite-basalts, trachyandesites and dacites), Ⅱ - 800-700 ka (ignimbrites, rhyodacites, dacites and andesites), Ⅲ - 225-170 ka (dacites), Ⅳ - 110-70 ka (dacites) and Ⅴ phase - less than 35 ka (dacites); ⅱ) four phases have been defined for the Kazbek centre: Ⅰ - 460-380 ka (basaltic andesites and andesites), Ⅱ - 310-200 ka (latest phase - andesites and dacites, earliest phase - basaltic trachyandesites, basaltic andesites, and dacites), Ⅲ - 130-90 ka (latest phase - dacites, earliest phase -andesites and trachyandesites), Ⅳ - less than 50 ka (andesites and dacites); ⅲ) for the Keli centre, three phases have been defined: Ⅰ - 245-170 ka (dacites, rhyolites and andesite-dacites), Ⅱ - 135-70 ka (earliest phase - dacites and rhyolites, latest phase - dacites, rhyolites, andesites and trachyandesites), Ⅲ - less than 30 ka (dacites and andesites). Owing to the Holocene age of the latest phases of volcanic activity, these volcanic centres ought to be regarded as potentially active (dormant).