Paleosol sequence, Pliocene red clay sequence and sand or sandy sediments (Fig. Ideal and simplified profile of red clay sites in Hungary. Schematic map showing the study areas of red clay sediments in Hungary, modified after Horvath and Bada. It consists of mainly three types of sediments from upper to the lower: Quaternary loess-įig. These sections are of Pliocene and Early Pleistocene age. The investigated sections selected for this study are located mainly on the foothills of Hungarian mountains (Fig. This paper deals with geochemical analysis of the red clay formation in the Carpathian Basin and evaluates chemical weathering intensities. The older one (red clay) was formed in the Early and Middle Pliocene. The youngest red paleosol (or reddish clay) is of Early Pleistocene age. Litho-, bio-, chemo- and magnetostratigraphic data show that they were formed in different periods. Important key formations in the Late Cenozoic stratigraphy are the red (silty) clays in the Carpathian Basin. Furthermore chemical weathering was studied using geochemistry. The most significant progress made on the red clay research worldwide is that sedimentology, geochemistry, geomorphology and field survey all demonstrate a windblown origin for the red clay, like the overlying Pleistocene and Holocene loess. Complex investigations including geology, geo-morphology, mineralogy and geochemistry were carried out only a few authors like Schweitzer and Szoor and Kovacs. Many geologists draw parallels between red clays and bauxites. Different views on the formation, properties and distribution of red clays have been published by several authors. In the past decade little attention has been paid to the red clay in the Carpathian Basin. Very little work had previously been done in this topic in Hungary. CHEMICAL WEATHERING INTENSITY OF THE LATE CENOZOIC "RED CLAY" DEPOSITS IN THE CARPATHIAN BASINĭepartment of Geology, University of Pecs, Ifjüsag ütja 6, Pecs, H-7624 Hungary e-mail address: Received August 10, 2006