Эволюция русловых систем от нижнего карбона до квартера (на примере Удмуртии)

Here, paleochannels of different geological periods are considered as evolutionary links of erosional systems. The paper presents the materials of geophysical studies (land seismic survey in combination with drilling data) using the common depth point (CDP) method within the Chutyrsko-Kiengopskaya group of oil fields over an area of more than 1.8 thousand km² for the period from 1999 to 2017. As a result, a paleochannel was identified, which has a linear shape with the beginnings of meanders, more than 60 km long and from 1.5 km in the north to 2.5–4 km in the central and southern parts of the study area. The depth of the river paleovalley varied from 60 m in the northern part to 80–100 m in the central part and decreased to 35–50 m in the southern part, where it had a pronounced floodplain. It was established that the course of the paleo-river passed from north to southeast. A comparative analysis of the morphological and morphometric features of the paleochannels of the Lower Carboniferous and the Neogene-Quaternary time showed that the depth of the Pliocene incisions of modern rivers significantly exceeds the Visean, and the paleochannels of the Quaternary are close in morphometric parameters to the Lower Carboniferous. If the Paleozoic incisions can be potential hydrocarbon traps, then the Neogene-Quaternary paleochannels usually contain deposits of sand and gravel materials, serve as a source of conditioned fresh groundwater, less often alluvial placer deposits.