Preliminary data on the K-Ar dating of the basic rocks from the region southerly of Momchilgrad, Eastern Rhodopes, Bulgaria

Abstract

Volcanic rocks from the Eastern Rhodopes depression near to Bulgarian-Greek border are investigated. Six samples of basic altered rocks from 4 dykes and 2 larger bodies located into Kapinovo graben and Kushla volcano-tectonic structure are characterized. The K-Ar age of the basic dykes and small bodies is (31-32.5)±1.3 Ma and they are referred to the Early Oligocene (Rupelian). The time-span of the formation of the dykes corresponds as a whole to the time-span of the paroxismal volcanic events in the East Rhodope Volcanic Area.