Analysis of clay minerals in Hungarian loesses on the basis of the clay mineral map of soils in Hungary [antikvár]

ANALYSIS OF CLAY MINERALS IN HUNGÁRIÁN LOESSES ON THE BASIS OF THE CLAY MINERAL MAP OF SOILS IN HUNGARY P. STEFANOVUS ABSTRACT The clay mineral map of soils (Fig. 2) provided data for analysis of the the mineral composition of loess as a parent material. It was found tiiat the ratio of illite and chlorite,and smectite and vermiculite variés from region to region. The amount of chlorite increases in the Alpine region while the ratio of smectites increases in the vicinity of andesite mountains and, in regions bordering Pannonian deposits. In the international literature loesses are usually described by their grain size distribution, the amount and ratio of heavy minerals and the distribution of carbonates. Studies on the amounts and qualities of clay minerals are much fewer in number, although these depend partly on the rock conditions of the source area of windblown dust and partly on the diagenesis during loess formation. In order to contribute new data to the classification of loesses, we have selected from the clay mineral map of soils, our information base, profiles in which field description indicated loess as a parent material. After evaluation régiónál patterns, worthy of mention were obtained. When constructing the ciay mineral map of soils a number ot mineralogical, colloidical and pedological analyses were made. Here the results of x-ray diffraction examinations of oriented samples from the clay component are shown for certain representative sainples. The sampling sites are mapped on Fig. 1 and data in Tablc 1. The X-ray diffraction analyses were carried out in the Central Research lnstitute for Chemistry of the Hungárián Academy of Sciences, while the evaluation of curves and the disclosure of spatial relationships were undertaken by ourselves.