Mineralogy of soils on the Baer mounds in southern Astrakhan oblast

Abstract

The methods of X-ray diffractometry, scanning electron microscopy, and energy dispersion analysis have been used in the mineralogical study of Baer mound soils in the southern part of the Astrakhan oblast. It has been established that such framework minerals as quartz and feldspars form the basis of the mineralogical composition of soils and mound deposits. It has been shown that the mound topsoils have similar mineralogy along the entire profile. Besides the essentially higher content of layered minerals, the soils at the foot of the mound and in the intermound hollow are characterized by a binomial mineralogical profile. Kaolin, chlorite, illite, illite-smectite, and smectite have been identified in the clay fraction of the soils. The processes of illitization growing down the slope and along the soil profile have been recognized in the soils.