About conditions of formation of some agate deposits of Transcaucasia

Abstract

In geological literature the conditions of formation of agate deposits are covered very one-sidedly. Most of the published works devoted to the genesis of agate mainly consider the mechanism of chalcedony filling of voids in rocks and formation of agate banding. However, search criteria are necessary for finding agate deposits, which can be developed only on the basis of clear ideas about the conditions of deposit formation. The host rocks for all agate deposits in Transcaucasia are volcanogenic formations, mainly of andesite composition. Agate deposits of the Akhaltsikhe region of the Georgian SSR are localized either in glassy andesite covers or in the thickness of andesite tuffobreccia and tuffoconglomerates. In terms of age, the rocks belong to the upper middle, lower upper Eocene ...