Mesozoic sediments in the Upper Priamurye were first established by F. B. Schmidt in 1859. In 1887‑1890, these sediments were subdivided into Lower and Middle Jurassic by L. Bacevich. Based on the first collected complex of fossil marine fauna, the age of the host sediments was dated to the Lower‑Middle Jurassic by A. I. Khlaponin. The Mesozoic formations of the Upper Priamurye were divided into two complexes in 1941 by V. Z. Skorokhod: marine Jurassic sediments (Bureya Formation) and freshwater‑continental Cretaceous sediments (Nikan Formation).