Raucha sedimentary basin (Jurassic (Volgian) to Early Cretaceous) (Northeastern part of Russian Northeast, unit KJs) Chiefly shallow-marine sedimentary rocks, mainly sandstone, siltstone, and mudstone with minor rhyolite, dacite, and andesite tuffs and flows. Contains Buchia and ammonites. Sedimentary and volcanic rocks of unit unconformably overlie Triassic and Early Jurassic deposits of Anyui and Chauna subterranes of Chukotka terrane. REFERENCES: Gorodinskiy and Paraketsov, 1960; Paraketsov and Paraketsova, 1989.