UstKolumbe Fm

Koppi-Luzhki zone and Kema zone of Eastern Sikhote-Alin Basin

Synonym: Ust-Kolumbe Fm (actual name; but Lexicon inter-linking is confused by hyphen in Fm name)

The Ust-Kolumbe Formation is widespread in the Koppi-Luzhki zone (Markevich et al., 2000). It comprises mainly sandstones with subordinated siltstones and lenses of gravelstones and conglomerates with a total thickness of up to 1200 m (Turbin, 1994; Markevich et al., 2000). In the Kema zone, the formation is represented by flysch composed of alternating sandstones, siltstones and gravelstones with a total thickness of up to 1000 m.

In the Kema zone, the formation does not contain any fossils and its Hauterivian range is determined only by its position in the section. In the Koppi-Luzhki zone, it yields inoceramid bivalves Inoceramus ex gr. peltiformis, I. ex gr. aucella and I. colonicus (Turbin, 1994; Markevich et al., 2000). The first two species are typical for the Hauterivian and the latter species occurs in the Hauterivian and Barremian (Pergament, 1965; Pokhialainen, 1969).