Lithological–Facies Features and Formation Conditions of Paleogene Zeolite-Bearing Complexes of the Eastern Ciscaucasus

Paleocene and Eocene terrigenous–siliceous complexes of the Eastern Ciscaucasus contain 18–92% zeolites represented by clinoptilolite. The studied complexes are the stratified subplatformal shallow-water subaqueous deposits with abundant authigenic silica as skeletal remains, cryptocrystalline substance, and pyroclastic material. Clinoptilolite in Paleocene–Eocene terrigenous–siliceous sediments formed from the mud solutions mainly at the expense of the labile pyroclastic material and biogenic silica. Variations in the zeolite abundance are explained by different contents of the pyroclastic material and SiO₂in the primary sediment.