The K-Ar and Rb-Sr isotopic systems in rocks from the Jurassic terrigenous complex of the Greater Caucasus

The behavior of K-Ar and Rb-Sr isotopic systems in clayey rocks from the Jurassic terrigenouis complex of the Greater Caucasus sampled along the Terek River is discussed. It is shown that the rocks experienced intense postdiagenetic alterations accompanied by substantial changes in mineral composition and K-Ar and Rb-Sr isotopic systems. Lateral stress is the leading factor responsible for secondary mineral and geochemical transformations of rocks in cleavage zones. Rejuvenation of the radiological age of rocks, relative to their stratigraphic age, is 100 Ma and more. The age estimate of approximately 50 Ma obtained for samples from the southern limb of the anticlinorium reflects the Paleocene-Eocene phase of tectonic activity manifested in both the Caucasus and other areas of the Mediterranean foldbelt.