Yenisei–Khatanga Composite Tectono-Sedimentary Element, northern east Siberia

Abstract

AbstractThe Yenisei–Khatanga Composite Tectono-Sedimentary Element (CTSE) is located between the Siberian Craton and the Taimyr–Severnaya Zemlya Fold and Thrust Belt. The total thickness of the Mesoproterozoic–Cenozoic sediments of the Yenisei–Khatanga CTSE reaches 20–25 km, and they are divided into four tectono-sedimentary elements (TSEs): (i) Mesoproterozoic–early Carboniferous Siberian Craton continental margin; (ii) middle Carboniferous–Permian synorogenic Taimyr foreland basin; (iii) late Permian–Early Triassic synrift; and (iv) Triassic–Early Paleocene post-rift. The last one is the most important in terms of its petroleum potential and is the most drilled part of the CTSE. Its thickness accounts for half of the total thickness of the Yenisei–Khatanga CTSE. The margins of the post-rift TSE and the inner system of inversion swells and adjacent troughs and depressions were shaped by three tectonic events: (i) Middle Triassic uplift of South Taimyr; (ii) the Late Jurassic–Early Cretaceous Verkhoyansk Orogeny; and (iii) Late Cenozoic uplift. These processes led to more intense migration of hydrocarbons, the trap formation and their infill with hydrocarbons. Triassic, Jurassic and Lower Cretaceous source rocks are mostly gas-prone; and of the 20 discovered fields in Jurassic and Cretaceous plays, 17 are gas or mixed-type fields.