A deep North Chukchi Trough is located in the Chukchi Sea to the north from Wrangel Island. It is filled by the Aptian-Cenozoic sedimentary cover represented by multistorey clinoform complexes. Postneocomian clinoforms of the Alaska North Slope are productive on several oil and gas fields onshore. These petroleum accumulations are associated mostly with stratigraphic traps, which makes sequence stratigraphic approach an effective tool for its prediction. Sequence stratigraphic analysis of Chukchi Sea clinoforms has been carried out by a few Russian and international specialists. This work is based on offlap break trajectory analysis allowing definition of the most valuable surfaces subdividing sedimentary successions. This resulted in identification and mapping of 18 clinothems, which were combined into 6 seismic complexes by the unity of sedimentary transport direction. Regressive stages of clinoforms progradation were interrupted by transgressions of various scales. The most extensive transgressions resulted in one seismic complex upbuilding another forming multistorey sedimentary cover of the North Chukchi Trough. The offlap break migration distance is the longest at clinothems formed after such transgressions, while it gradually decrease from the lower to upper parts of the seismic complexes. The clinothem heights are a proxy of palaeo-bathymetry of the sedimentary basin. Maximal clinothem heights correspond to the palaeo-continental shelf development in the later Cretaceous – middle Paleocene and modern continental in the Pliocene-Pleistocene. Minimal clinothem heights represent Mid-Paleogene – Mid-Neogene (?) subaqueous deltas development on the continental shelf. Clinothems oblique overlapping causes substantial spatial differences in clinothem heights. The clinothems characterise by different offlap break trajectories, which are mostly either progradation to aggradation or aggradation to progradation. This is one of the interpretation criteria to distinguish between low and high systems tracts correspondingly. Straight and jigsaw types of offlap break trajectories are a more detailed characteristic of the trajectories. The jigsaw trajectory testifies for the formation of the transgressive systems tracts within clinothems. Based on the analysed factors, the sedimentary cover is subdivided into low, high, and transgressive composite systems tracts.
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