ABSTRACT

Composition, stratigraphic and structural position of Jurassic-Lower Cretaceous radiolarian-rich siliceous rocks and black shales are described within allochthonous lithotectonic complexes of the Koryak-Western Kamchatka orogenic belt of East Asia. Comparative lithological and stratigraphic analysis of sedimentary units exposed in imbricated tectonic slices over a distance of more than 1000 km helped to restore a continuous succession of siliceous rocks from Hettangian to Barremian. The Jurassic-Lower Cretaceous siliceous succession is composed of Hettangian and Aalenian-Barremian haematitic jaspers and Sinemurian-Toarcian radiolarian-bearing pyrite-bearing organic-rich black cherts and siliceous shales. Allochthonous Jurassic-Lower Cretaceous siliceous successions of the Koryak-Kamchatka orogenic belt likely accumulated in some open pelagic domains of the Paleo-Pacific within the Izanagi-Kula plate at different paleo-latitudes from high (southern boreal) to subequatorial (northern Tethys) paleo-latitudes. Depositional environments of Sinemurian-Toarcian organic-rich black shales were characterized by euxinic deep-water paleo-oceanic settings with poor water circulation. Accumulation of the Toarcian black shale succession corresponds in time to a global Toarcian oceanic anoxic event, while deposition of regionally occurring Sinemurian-Pliensbachian black shales was likely controlled by local factors. Hettangian, Middle Jurassic to Upper Jurassic-Barremian haematitic jaspers accumulated under aerobic conditions with well-circulated waters enriched with oxygen.

摘要

在东亚科里亚克-堪察加西部造山带的外地岩石构造杂岩中描述了侏罗纪-下白垩统放射虫丰富的硅质岩和黑色页岩的成分、地层和构造位置。对 1000 多公里外覆瓦状构造切片中暴露的沉积单元的比较岩性和地层分析有助于恢复从 Hettangian 到 Barremian 的连续连续的硅质岩层序。侏罗纪-下白垩统硅质层序由赫坦阶和阿伦阶-巴雷姆阶赤铁质碧玉和西尼穆尔阶-托尔奇阶放射虫黄铁矿富含有机质黑色燧石和硅质页岩组成。科里亚克-堪察加造山带的异地侏罗纪-下白垩纪硅质层序可能聚集在伊邪那岐-库拉板块内的古太平洋的一些开阔中上层区域，从高纬度（北部北部）到赤道下（特提斯北部）古-纬度。Sinemurian-Toarcian富有机质黑色页岩的沉积环境以常温深水古海洋环境为特征，水循环不良。Toarcian黑色页岩层序的堆积与全球Toarcian海洋缺氧事件及时对应，而区域性Sinemurian-Pliensbachian黑色页岩的沉积可能受局部因素控制。黑腾人，