Divnaya Fm

Koppi-Luzhki zone of Eastern Sikhote-Alin Basin

It is composed of siltstones, sandstones, gravelstones and siliceous-clayey rocks with a total thickness of up to 1000 m.

The lower part of the formation yields ammonites Leconteites sp., Puzosia alaskana, Grantziceras glabrum and bivalves Aucellina caucasica, Aucellina aptiensis, Aucellina anthulai, Leda sp. ind., Thracia sp., Variamussium sp., Nucula sp., Solemya sp. ind., Entolium sp. nov., Oxytoma ex gr. canselli, Mactromya sp., Thetironia sp. (Turbin, 1994; Markevich et al., 2000). The upper part of the formation is characterized by ammonites Puzosia alaskana, Grantziceras glabrum, Cleoniceras sp., Anagaudriceras sp., Colvillia sp., bivalves Aucellina caucasica, A. aptiensis, A. anthulai, Inoceramus cf. anglicus, Nucula sp., Entollium sp., Astarte sp. ind. and echinoids Hemiaster cf. judinkensis (Turbin, 1994; Markevich et al., 2000). Stratigraphically important fossils are Aucellina caucasica, A. aptiensis, Oxytoma ex gr. camselli distributed in the Aptian-Albian in Sikhote-Alin and Aucellina anthulai characterizing the lower Albian of Sikhote-Alin (Zonova and Yazykova, 2004). Ammonite Leconteites sp. is typical for the lowermost Albian and Puzosia alaskana characterizes the lower Albian (Imlay 1961; Jones et al., 1965; Jones, 1967; Jeletzky, 1970). Ammonites Eogaudriceras shimizui menneri, Puzosia alaskana, Grantziceras glabrum and Cleoniceras? sp. from the upper part of the formation are lower Albian index fossils (Imlay 1961; Jones, 1967; Jeletzky, 1970; Alabushev, 1989). Typical Inoceramus anglicus is known from the middle and upper Albian, but similar forms are also known from the lower Albian of the North Pacific region (Imlay, 1961; Pergament, 1978; Zonova and Yazykova, 2001).