Deep structure and prospects of ore and petroleum bearing capacity of the North-Western part of the Momo-Selennyakh depression

Abstract.The article presents the results of medium-scale geological mapping of the Momo-Selennyakh depression. New data on the deep structure, ore and oil-and-gas bearing capacity of the depression were established. Reliable and presumptive signs of oil and gas content were revealed. The geologic structure of the depression, including its location in the Kolyma-Omolon superterrane bordering the Verkhoyansk fold system, was discussed. The Momo-Selennyakh depression is located within the Kolyma-Omolon superterrane, which borders the Verkhoyansk fold system. The depression was formed as a result of crustal stretching in the Late Pliocene – Early Pleistocene. It is composed of sand and gravel deposits of Miocene and Pliocene age overlain by Pleistocene glacial formations. The Selennyakh and Syuryuktyakh depressions are part of the Momo-Selennyakh depression, which is located within the Kolyma-Omolon superterrane. The Selennyakh depression has a gentle shape and is composed of Upper Jurassic sedimentary-volcanogenic formations. The basement of the depression is disrupted by faults along which the blocks moved.The Syuryuktyakh depression has a more complex structure and is composed of loose sediments of PaleogeneNeogene and Quaternary age. The basement of the depression is composed of Upper Silurian and Devonian carbonate sediments and Upper Jurassic sedimentary-volcanogenic formations. The depression was formed in the zone of the large Ulakhan fault. The results of hydrogeochemical sampling indicate the presence of hidden mineralized crushing zones associated with the Ulakhan fault. These zones have elevated contents of cadmium, boron, copper, zinc, lead, molybdenum and other metals. The presence of bituminous shales, increased content of naphthenic acids, iodine, bromine and fluorine in waters, as well as the presence of oily patches and griffons with gas emission indicate possible oil-bearing capacity of the area.