On the different origins of structural deformations of sediments in a hydroplastic environment

Abstract

In the past decade, there has been increased interest in periglacial phenomena, resulting in numerous descriptions of structural deformations in Quaternary sediments in Poland, mainly interpreted as effects of Pleistocene frost processes. Studies in the Carpathians have shown that similar deformations can occur under subaqueous conditions due to gravitational flows of hydroplastic sediments, their water saturation, and low cohesion, as observed, for example, in Rożnowskie Lake. Subaqueous sediments also develop involution structures, such as flow casts and load casts, formed by the loading of layers with different grain sizes. The author emphasizes the need for caution when interpreting fossil intra-layer deformations in Pleistocene sediments, as the external similarity of forms with different origins may lead to incorrect conclusions about their periglacial origin.