Sarykul paleosol in Southern Urals sediments (Russia)

Abstract

Sarykul paleosols in the Southern Urals (Russia) with a stable position in geological sediments are considered. The Brunhes-Matuyama boundary was found in these paleosols and they were used as a source of information on the environment. Data were obtained during the study of the Sarykul paleosols in four sections located in the mountain part of the Southern Urals on the Miass River erosion-accumulation terrace and at the eastern edge on the trans-Uralian peneplain. Saykul paleosols have a relatively thick and compact humic horizon with a tongued lower boundary. The paleosols are dark grey with high TOC content that is not usual for the Early Pleistocene paleosols. The materials showed that Sarykul paleosols formed on different parent rocks may have various characteristics of the mineral part (texture, pH, magnetic susceptibility, carbonate content, ratio of exchangeable cations), while their humic substances characteristics (humic and fulvic acid ratio, humic acid characteristics of elemental composition and structure) are very similar. Climate conditions during Sarykul paleosol formation changed from relatively warm and humid to less warm and more humid. The study of Southern Urals Sarykul paleosols has shown that they can serve as a reliable marker of the final Early Pleistocene due to their specific characteristics, not analogous to the modern soils.