Abstract—

The analysis of the recognized Late Cretaceous radiolarian assemblages from various structural and formation zones of the Olyutor and Algan terranes of the Koryak Highland has revealed a significant difference in their taxonomic composition, the quantitative content of radiolarians, and their morphological features. The radiolarian assemblage of the Olyutor terrane, which occupies the southern part of the Koryak Highland, consists of almost 100% Californian radiolarian species. The radiolarian assemblage of the Algan terrane, which is located in the northwestern part of the Koryak Highland, contains 50% or more species described from sections of the Russian Plate and Western Siberia and no more than 50% Californian species. These data clearly show the relationship between the Algan paleobasin and the paleo-Arctic and West Siberian Sea under the simultaneous influence of the Pacific currents, following which Californian species could pass to the basin. The Olyutor terrane had a close connection with the Paleopacific in Late Cretaceous. At the same time, most of the taxa which are most characteristic of the Olyutor zone were also distributed in the Upper Cretaceous/Paleocene of New Zealand. Among them are both cosmopolitan and probably bipolar species, which most likely include Stichomitra livermorensis, Theocampe altamontensis, T. vanderhoofi, Bathropyramis sanjoaquinensis, Praestylosphaera pusilla, and P. hastata. A biostratigraphic division in the rank of beds with fauna—the beds with Prunobrachium articulatum—was first identified in the Algan Zone (northwestern part of the Koryak Highland). Currently, the level with Prunobrachium articulatum is subglobal and is traced from Western Siberia, where it was first established, both to the west to the Russian Plate and the east to the Pacific margin inclusive. Several levels are suggested in the Olyutor zone (southern part of the Koryak Highland): the first occurrence of Praestylosphaera pusilla (F.O.) and Phaseliforma meganosensis (F.O.) and the last occurrence of Orbiculiforma quadrata (L.O.) at the Santonian–Campanian boundary; the first occurrence and abundance of Dictyomitra densicostata in the Lower Campanian; an abundance of Phaseliforma carinata, Stichomitra livermorensis, and Archaeodictyomitra regina and the first appearance of Clathrocyclas hyronia and Lithomespilus mendosa in the upper Campanian/Maastrichtian. The biostrata distinguished in the Koryak Highland were correlated with biostratons of adjacent territories in the Pacific region.

中文翻译：

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来自俄罗斯东北部高里亚克高原地带的Campanian–Maastrichtian放射虫

摘要-

对来自Koryak高地的Olyutor和Algan地形的各种结构和形成区的晚白垩世放射虫组合的分析表明，它们的分类学组成，放射虫的定量含量及其形态特征存在显着差异。Olyutor地形的放射虫组合体占据了Koryak高地的南部，几乎由100％的加利福尼亚放射虫物种组成。位于Koryak高地西北部的Algan地形的放射虫组合包含俄罗斯板块和西西伯利亚部分地区描述的50％或更多的物种，加利福尼亚州的物种不超过50％。这些数据清楚地表明，在太平洋洋流的同时影响下，阿尔古古盆地和古北极与西西伯利亚海之间的关系，随后加利福尼亚物种便可以进入该盆地。Olyutor地形与白垩纪晚期的古太平洋有着密切的联系。同时，大多数具有Olyutor带特征的分类单元也分布在新西兰的上白垩统/古新世。其中包括世界性物种，也可能是双极物种，其中最有可能包括 Olyutor带最有特色的大多数分类单元也分布在新西兰的上白垩统/古新世。其中包括世界性物种，也可能是双极物种，其中最有可能包括 Olyutor带最有特色的大多数分类单元也分布在新西兰的上白垩统/古新世。其中包括世界性物种，也可能是双极物种，其中最有可能包括Stichomitra livermorensis，Theocampe altamontensis，T. vanderhoofi，Bathropyramis sanjoaquinensis，Praestylosphaera pusilla和P. hastata。在动物群床层中的生物地层划分-带有Prunobrachium articulatum的床层-首先在Algan地区（Koryak高地西北部）被确定。目前，Prunobrachium articulatum的水平是次全球性的，可追溯到最早建立的西伯利亚西部，西至俄罗斯板块，东至太平洋边缘。在Olyutor区域（Koryak高地的南部）提出了几个级别的建议：Praestylosphaera pusilla的首次出现（FO）和菜豆（FO）以及桑托尼亚-坎帕尼亚边界上最后一次发生的小bic（LO）。Dictyomitra densicostata在下Campanian的首次出现和丰富；大量的菜豆，Stichomitra livermorensis和Archeeodictyomitra regina，以及在上Campanian / Maastrichtian的Clathrocyclas hyronia和Lithomespilus mendosa的首次出现。高丽亚高地的生物群落与太平洋地区邻近地区的生物层相关。