We propose a scheme to subdivide the Samarka terrane, a Jurassic accretionary prism fragment, into tectonostratigraphic complexes. This subdivision provides a basis to study these formations and map them on a medium- to large-scale. Each complex corresponds to a certain stage in the accretionary prism formation. Thus, the complexes composed of subduction mélange and olistostromes (in our case, Ust-Zhuravlevka and Sebuchar complexes), can be correlated to episodes when the underthrusting of seamounts hampered subduction, as evidenced by seamount fragments contained in the complexes. Episodes of relatively quiet subduction have also been identified, resulting in complexes composed mainly of normally bedded terrigenous and biogenic formations (Tudovaka and Udeka and, partially, Ariadnoe complexes). Particularly considered is the Okrainka-Sergeevka allochthonous complex – a fragment of continental plate overhanging a subduction zone. It was included in the accretionary prism during gravitational sliding on the internal slope of the paleotrench. All volcanic rocks in the accretionary prism are allochthonous fragments of the accreted oceanic crust. The absence of the Jurassic-Berriasian volcanic belt related to this prism, as well as synchronous autochthonous volcanism, indicates that the Samarka terrane accretionary prism formed under conditions of flat-slab subduction, similar to modern examples along the Andean margin.

The Miocene plant megafossil assemblages from the circum-Japan Sea areas, including southern Primorye, Korea, and Japan, were reviewed in terms of floristic composition and physiognomic characters. These attributes were used to understand the vegetation history during the formation of the Sea of Japan with its effects on floristic changes in each area. There was a temperature increase from the early early Miocene to the middle Miocene with a peak at the early– middle Miocene boundary, and subsequent temperature drop in the late Miocene in all floral successions. The early Miocene assemblages from each area are similar to one another, but the number of common species between those from the southern Primorye and Japanese Islands decreased since the middle Miocene, suggesting an influence of geographic separation of these areas possibly due to the rifting of the Sea of Japan. The degree of temperature increase was larger in the southern part (the Japanese Islands and southern Korean Peninsula), whereas it was much smaller in the northern part (southern Primorye and northern Korean Peninsula). Effects of cold and warm water currents both toward the north and south of the Sea of Japan were suggested for floristic differentiation of these areas.

The Kema terrane is a suite of Barremian(?)-Aptian to Albian volcano-sedimentary rocks of Sikhote-Alin that are interpreted as deposits of the back-arc basin of the Moneron-Samarga island-arc system. Compositional features of the different-type deposits indicate a near-slope depositional environment influenced by volcanic processes. Studies of slump fold orientation testify to the accumulation of material from southeast to northwest by gravitational sliding. Compositional characteristics of terrigenous rocks suggest the major provenance for detrital material was an ensialic volcanic island arc. Petrochemical characteristics of basaltic rocks indicate that the formations studied were confined to the back part of the arc.