Abstract—

The results of study of the Middle Miocene Il’inskii Regional Stage of Western Kamchatka and its typical mollusks are presented. Its age analogs are identified in Japan, on Sakhalin, and in the Koryak Upland. The features of the distribution of mollusk assemblages of the beginning of the Middle Miocene are revealed at various latitudes of shelf zones of Northwestern Pacific. It is suggested that the warm (subtropical and low boreal) mollusk assemblages migrated at the beginning of the Middle Miocene from the latitudes of Japan to Northern Kamchatka. This event was probably related to the global Miocene warming, which led to certain changes in the oceanic hydroregime, in particular, to the movement of relatively warm water masses to the north. In the North Pacific, this event followed the tectonic reconstructions, which affected the evolution of marine transgression reflected in the formation of sedimentary complexes of many regions of the world.

中文翻译：

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西堪察加中新世伊林斯基地区阶段：软体动物组合和古生物地理解释

摘要——

介绍了西堪察加中新世伊林斯基地区阶段及其典型软体动物的研究成果。它的年龄类似物在日本、萨哈林岛和科里亚克高地都有发现。西北太平洋陆架带不同纬度揭示了中中新世初期软体动物组合的分布特征。这表明温暖的（亚热带和低寒带）软体动物组合在中中新世初期从日本纬度迁移到堪察加北部。这一事件可能与全球中新世变暖有关，导致海洋水文体系发生某些变化，特别是相对温暖的水团向北移动。在北太平洋，这一事件发生在构造重建之后，