Paleoenvironmental reconstruction based on the morphology and distribution of secondary carbonates of the loess-paleosol sequence at Süttő, Hungary

Micro- and macroscale secondary carbonates were investigated from the loess-paleosol sequence of Süttő, Hungary. As secondary carbonates are formed in pedosedimentary environments, they designate how the microecosystem adapts to dust accretion. Besides pedogenic aspects, the hints of diagenesis can be tracked, especially concerning leaching effects. The main goal of this study was to make an attempt whether the distribution-related signals of secondary carbonates combined with their genetic properties can be used for paleoenvironmental reconstruction. The elaborated method is wet sieving of bulk loess/paleosol samples in order to: 1) separate secondary carbonates to describe morphological properties, partly with the help of scanning electron microscopy; and 2) provide a depth-related semiquantitative distribution. The semiquantitative distribution is ordered to the marine isotope stage units of the Süttő sequence (MIS 6 to 2). The MIS 6 section is characterized by presumably slower dust accumulation and raises the possibility of a multiphase leaching history throughout the profile. Lower dust accumulation rates with increasing aridity are assumed upwards in MIS 5. MIS 4 is typified by arid conditions and the alternation of lower and higher dust accumulations. Certain properties of paleosol development and frost deformation related to secondary carbonates can be distinguished in MIS 3. Dust accumulation rates are presumed to be consistent upwards in this section. During MIS 2, different sedimentation stages are distinguished, but generally they show a decreasing trend upwards to the modern soil. This work serves as a complementary method which may help to refine the paleoenviromental signals of the Süttő loess-paleosol sequence to determine relative sedimentary phases. The limitations of the method have to be taken into consideration, as the results are semiquantitative.