黄河物源碎屑沉积物的重矿物特征

CHARACTERISTICS OF MINERALOGY IN THE CLASTIC SEDIMENTS FROM THE YELLOW RIVER PROVENANCE, CHINA

对取自黄河口附近的黄河干道和分流河道、河口潮间带及水下三角洲不同地貌沉积环境的149个表层样品进行了碎屑矿物学研究。结果表明,近代黄河物源碎屑沉积物与长江物源相比,具有云母 普通角闪石 绿帘石组合,富含云母类矿物,但不同环境的矿物组成由于沉积动力条件的不同而有较大变化,以黑云母/白云母和磁铁矿/钛铁矿比值高以及绿帘石/榍石和闪石类/辉石类比值低为特征。

149 heavy mineral samples in clastic sediments collected from the river channel, tidal flat and undersea delta in the vicinity of the Yellow River Estuary were analysed. The analysis result shows that the micahornblendeepidote association comprises biotite, amphiboles, muscovite, ilmenite, limonite, garnet, zircon, apatite, magnetite, titanite, and pyroxenes etc. The mineral components are variant in different geomorsedimentary environments due to different dynamic conditions. The micahornblendeepidote association occurs in the channel and distributary channel sediments enriched in magnetite, ilmenite, zircon, and apatite. The micahornblende association occurs in the tidal flat, containing limonite, authigenic pyrite and collephane, whereas mica groups are significantly rich and the content is up to 70% in the undersea delta.Compared to the Yangtze River, the Yellow River provenance is characterized by rich micahornblendeepidote assemblage, high biotite/muscovite and magnetite/ilmenite ratios and low epidote/titanite and amphiboles/pyroxenes ratios.