Open AccessRelict cryogenic structures in the landscapes of Orenburg region, Russia
Author(s) -
A. G. Ryabukha,
Irina Streletskaya,
D. G. Polyakov,
И. В. Ковда,
I. G. Yakovlev
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/817/1/012093
Subject(s) - permafrost , thermokarst , pleistocene , ice wedge , geology , pseudomorph , loess , pedogenesis , holocene , wedge (geometry) , geomorphology , glacial period , geochemistry , paleontology , physical geography , earth science , geometry , soil science , soil water , geography , oceanography , quartz , mathematics
The evidence of Neo-Pleistocene and possibly Holocene paleopermafrost was found in Orenburg region, Russia. Large polygons are clearly visible in relief, which indicate the existence of continuous low-temperature frozen rocks in the past. We found and studied the structure of the ground wedges formed in sediments of different composition and genesis. Ground wedges in loess-soil formations indicate several stages of permafrost expansion at the end of the Neo-Pleistocene. Freezing of ground was accompanied by the formation of polygonal-wedge ice and initially-ground wedges. During the warming periods the permafrost melted and pedogenesis restarted together with active thermokarst processes and formation of pseudomorphs along the wedge ice.