| Abstract: | Results of the isotope-geochronological studies of the Late Cenozoic magmatism of Caucasus have been considered. The Neogene-Quaternary
volcanic activity is found to have evolved during the last 15 m. y. being most intensive in the Middle-Late Pliocene. Within
separate neovolcanic areas of the Caucasus region, magmatism was of a clearly discrete character when intense eruption periods
interchanged with prolonged (up to several million years) times of quiet conditions. Four stages of young magmatism of the
Caucasus are recognized: the Middle Miocene (15–13 Ma), the Late Miocene (9–5 Ma), the Pliocene (4.5–1.6 Ma), and the Quaternary
(less than 1.5 Ma). However, for certain areas the time limits of these stages were shifted relative to each other and overlap
the whole age range from the mid-Miocene to the end of the Quaternary period. Therefore, within the collision zone, the Neogene-Quaternary
magmatism evolved almost continuously during almost the last 9 m. y., but in the time interval of 13–9 Ma in the Caucasian
segment, volcanic activity was possibly low. No evidence of directed lateral migration of volcanic activity within the entire
Caucasus region was found. At the same time, in the Lesser Caucasus the young magmatism commenced earlier (∼15 Ma), compared
to the Greater Caucasus (∼8 Ma). |
