GENESIS OF CLAY MINERALS IN PRE-CAMBRIAN METAMORPHOSED SEDIMENTARY ROCKS

Rok, strany: 1993, 93 - 99

The presence of high-alumina minerals such as kyanite, sillimanite etc. in Pre-Cambrian schists (or gneisses) is often treated as resulting from the metamorphism of terrigeneous kaolinite in sedimentary rocks. This implies the existence of kaoline weathering crusts. The study of Late Archean to Early Proterozoic residual rocks of the weathering crust indicates, however, that they are of montmorillonite-illite or chlorite-illite composition. The association of high-alumina minerals with carbonic matter (in the case of Early Proterozoic high-alumina concretion schists of the Kola Peninsula, Baltic Shield), as well as the geochemical peculiarities in the distribution of REE and other microelements in the rocks in question, their position in the section, and thermodynamic calculations of kaolinization for various minerals suggest an authigenic, diagenetic origin and subsequent metamorphism for kaolinite and clay concretions.

ISO 690:

G. Shchipakina, I. 1993. GENESIS OF CLAY MINERALS IN PRE-CAMBRIAN METAMORPHOSED SEDIMENTARY ROCKS. In Geologica Carpathica Clays, vol. 2, no.2, pp. 93-99.

APA:

G. Shchipakina, I. (1993). GENESIS OF CLAY MINERALS IN PRE-CAMBRIAN METAMORPHOSED SEDIMENTARY ROCKS. Geologica Carpathica Clays, 2(2), 93-99.