Relative contents of heavy minerals in 0.100-0.010 mm grain size fraction from bottom sediments of the southwest Barents Sea

Structure and composition of sub-surface bottom sediments from the southwest Barents Sea have been under study. The study has revealed heterogeneity of sediment structure resulted from temporal irregularity and variability of sedimentation processes. The study of the heavy minerals from 0.1-0.01 mm grain size fraction has shown prevalence of green hornblende, epidote, garnet, and ilmenite in all types of sediments; these minerals are the basis of terrigenous-mineralogical province. At the same time in different areas local terrigenous-mineralogical associations have been identified. Clay mineral composition of in the sediments was quite uniform: biotite, chlorite, hydromica, smectite. Despite this, a number of features indicating initial stages of clay mineral transformation has been identified. Differences in material composition and structure of the studied sediments are associated with rapid change in paleogeographic situation on the land - ice cover melting on the Kola Peninsula and subsequent Holocene climatic situation.

本研究聚焦巴伦支海（Barents Sea）西南部海域的次表层海底沉积物，对其结构与组成展开调研。研究结果显示，沉积物结构呈现不均一性，该特征由沉积作用的时间不规则性与过程变异性共同导致。针对0.1~0.01毫米粒级组分中的重矿物（heavy minerals）开展分析后发现，各类沉积物中均以绿角闪石（green hornblende）、绿帘石（epidote）、石榴子石（garnet）及钛铁矿（ilmenite）为主；上述矿物构成了该区域陆源矿物省的核心组分。与此同时，不同区域均识别出具有地域特征的陆源矿物共生组合。沉积物中的黏土矿物组成整体较为均一，主要包括黑云母（biotite）、绿泥石（chlorite）、水云母（hydromica）及蒙脱石（smectite）。尽管如此，研究仍识别出若干指示黏土矿物处于初始转化阶段的特征。所调研沉积物的物质组成与结构差异，与陆上古地理环境的快速变迁密切相关——即科拉半岛（Kola Peninsula）冰盖消融及随后全新世（Holocene）的气候格局变化。