Abstract

The results of petrographic, petrogeochemical and isotopic studies of sedimentary rocks obtained from bedrock outcrops of the Alpha–Mendeleev Rise, Arctic Ocean, using manipulators of a submarine research vessel (SRV) of the Russian Ministry of Defense during two expeditions conducted in 2014 and 2016 are considered and discussed in the article. Three sequences are identified in the basement of this Rise. The lower sequence (O₃–S₂) is composed of pure dolomite rocks (hereafter, dolomites proper), as well as dolomites with the terrigenous and bioclastic admixture, limestones with the terrigenous and bioclastic admixture, and quartz sandstones. They were formed in the coastal and shallow shelf environments of the tropical sea associated with carbonate platforms adjacent to river discharge areas. The middle sequence (D₂–D₃) is composed of limestones with the terrigenous and bioclastic admixture, as well as quartz–feldspar sandstones, which originated in coastal and shallow environments of the tropical sea. The upper sequence (K₁) is represented by the calcareous, clayey, and calcareous–clayey sandstones formed in shallow marine conditions. Maturity degree of the clastic material, which makes up sandstones of the three sequences, decreases from almost monomictic quartz arenites and sublitharenites of the lower sequence to subarkoses of the middle sequence and subarkoses, arkoses, litharenites, and wackes of the upper sequence. All sediments were accumulated in interacratonic sedimentary basins developed successively at passive margins of the Mendeleev microcontinent along with supercontinents Laurussia and Laurasia.

中文翻译：

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北冰洋阿尔法-门捷列夫隆起地下室的沉积岩

摘要

在 2014 年和 2016 年进行的两次探险期间，使用俄罗斯国防部潜艇研究船 (SRV) 的操纵器对从北冰洋 Alpha-Mendeleev 隆起的基岩露头获得的沉积岩进行岩石学、岩石地球化学和同位素研究的结果文章中考虑和讨论。在这个 Rise 的地下室中确定了三个序列。较低的序列（O ₃ –S ₂) 由纯白云岩（以下简称白云岩），以及含有陆源和生物碎屑混合物的白云岩、含有陆源和生物碎屑混合物的石灰岩和石英砂岩组成。它们形成于与邻近河流排放区的碳酸盐台地相关的热带海域的沿海和浅陆架环境中。中间层序（D ₂ -D ₃）由石灰岩与陆源和生物碎屑混合物以及石英-长石砂岩组成，起源于热带海域的沿海和浅层环境。上序列（K ₁) 以在浅海条件下形成的钙质、粘土和钙质-粘土砂岩为代表。构成三个层序砂岩的碎屑物质的成熟度由下层序的几乎单晶的石英砂岩和次岩屑岩向中层序的亚砂岩和上层序的砂岩、砂岩、岩屑岩和碎屑岩逐渐降低。所有沉积物均聚集在门捷列夫微大陆被动边缘以及劳鲁西亚和劳亚大陆超大陆相继发育的克拉通沉积盆地中。