This investigation is devoted to assessing the hydrocarbon potential of Upper-Tulian terrigenous complex of Dnieper-Donetsk depression (DDD), and value of the role of sedimentary-paleogeomorphological criteria of petroleum exploration in these strata. As an object of research were selected sediments of productive horizon V-21, with the most perspective, in our opinion, the central part of the DDD, namely territory Sribnenska depression and its frame. The vast amount of geological and geophysical examinations of this terrigenous complex within the area (a large number of key and parametric wells that uncovered it) allow to draw conclusions about patterns of formation of traps with its deposits.

According to the core samples it was analyzed the lithology of silt-sandy sediments and argillaceous rocks that contain them. The lithological composition of productive horizon V-21 is represented by mainly of deep-water kind dark-colored flysch clayey sediments. Sandstones are composed of quartz, gray to light gray colouring, of different granularity, of massive textures, or different lamination (cross-bedding, cross-ripple, moldlike, gradational interruptedly-horizontal- bedding).

Fine-grained sandstones are dominated by size of debris material. The matrix is represented by finely and coarsely big-scaled monoclinic kaolinite, in some cases the presence of degraded hydromicas impurities or rarely - carbonate (calcite, ankerite, siderite) is marked. The origin of sandstones is apparently associated with carryover riverine sandy material into stagnant type depressive basin, and subsequent distribution and re-deposition by underwater delta, turbidity and contour currents.

Built on logging data the lithofacial-paleogeologic profiles demonstrate patterns of silt-sandy bodies distribution in the vertical section. They occupy a subordinate position, forming layers, lenses, bar shapes ranging from 5 to 20 m and alternating between layers of mudstone and limestone. According to the log-based mapping of informative sedimentological parameters the spatial distribution pattern of silt-sandy rocks of productive horizon V-21 was defined. Sedimentary-paleogeomorphological prerequisites for the formation of oil and gas traps in these deposits were analyzed by using the examples of known fields.

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