Accession Number : AD0617560

Title :   WEATHERING EFFECTS ON THE STRUCTURES OF MICA-TYPE CLAY MINERALS.

Descriptive Note : Scientific rept.,

Corporate Author : COLUMBIA UNIV NEW YORK

Personal Author(s) : Guven,Necip ; Kerr,Paul F.

Report Date : FEB 1965

Pagination or Media Count : 40

Abstract : Mica-type clay minerals are subjected to an intensive weathering process in the basin of the Willard Reservoir, north of Ogden, on the playa margin of Great Salt Lake. Weathering attacks the interlayer region of the layer lattice silicates most intensively where the bonds are weakest. A continuous scattering in the lower angle region of the (001) - reflection with some sharp superimposed maxima shows the heterogeneity along the c-axis of the mica-type layers; it also shows the genetic relation between the mica-type layers with different basal spacings. The pronounced continuous scattering accompanying the (02,11) diffraction band on the Guinier photographs and the absence of (hkl) reflections show that the layer silicates in the Willard clays possess an intensive disorder in their a-b planes. The values of the b-dimensions, high SiO2/Al2O3 ratios and appreciable amounts of MgO + FeO + Fe2O3 indicate the mica-type layers are possibly derived from tetrasilicic members of dioctrahedral mica. The latter are often overlooked because of their easy alteration. (Author)

Descriptors :   (*MICA, DEGRADATION), (*CLAY MINERALS, DEGRADATION), UTAH, SOILS, SILICATES, CRYSTAL LATTICES, CRYSTAL SUBSTRUCTURE, X RAY DIFFRACTION, SILICON COMPOUNDS, ALUMINUM COMPOUNDS, MAGNESIUM COMPOUNDS, IRON COMPOUNDS, OXIDES

Distribution Statement : APPROVED FOR PUBLIC RELEASE