Specific features of clay minerals in ancient crusts of weathering of various rocks

Abstract

The most important typomorphic indications of clay formations in the studied crusts of weathering are as follows: a) omnipresent dioctahedral hydromica (2М1) in the crust of weathering of terrigenous-carbonate rocks and its association in the most mature profiles with kaolinite of relatively ordered structure, than of kaolinite, having been formed at the expense of other rocks; b) constant availability of trappean formation (tuffs, tufogene rocks, dolerites) in sections of crusts of weathering together with di- and trioctahedral montmorillonite, as well as disordered vermiculite-montmorillonite mixed-layered formation, to this or that degree disordered kaolinite, associated in the crust of weathering of tufogene rocks with halloysite (at complete absence of micaceous minerals in the products of weathering); c) the content in the crust of weathering of kimberlites together with polycationic montmorillonite of a significant quantity of trioctahedral chlorite (packets δ and δ'), serpentine (structural types A and B) and altered to various degree phlogopite, including related with it hydromica 1M.