APPLICATION OF LANDSCAPE INDICATORS OF GEOCRYOLOGICAL CONDITIONS IN INTERPRETATION OF GEOELECTRIC DATA
V.V. Olenchenko1, A.A. Zemlianskova2
1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
2St. Petersburg State University, St. Petersburg, Russia
Keywords: permafrost, electrical resistivity tomography, ground penetrating radar survey, talik, resistivity, cryosphere, phytoindication, bioindication
Abstract
The use of phyto- and bioindicators for interpreting geoelectric data in the study of permafrost sections is substantiated. The research used electrical resistivity tomography and ground-penetrating radar methods in various climatic and geocryological conditions from the Tien Shan to the Magadan region. In each region, specific landscape features of geocryological conditions were identified and compared with geoelectric sections or ground-penetrating radar data. Certain types of larch stands in Central Yakutia and birch stands in Transbaikalia together with data on high rock resistivity indicate the presence of permafrost with reduced temperature. In the northeast of Russia, poplars and willows (chosenia) grow in the area of talik zones, which allows interpreting areas of low electrical resistivity of rocks under them as taliks rather than the areas with pyritization or increased clay content. In the Tien Shan, a correlation was established between the electrical resistivity of a rock glacier and its age indicated by the size of Rhizocarpon sp. lichens. In mountainous areas, anomalies of low resistivity in places, where large anthills are concentrated, indicate the deep occurrence of permafrost table or open taliks in fault zones. Thus, taking into account landscape indicators of geocryological conditions helps us to reduce the ambiguity of geological interpretation of geoelectric data.
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