辽东湾中部晚第四纪沉积物物源与沉积环境:来自碎屑矿物和自生黄铁矿的证据

发布时间：2018-01-11 16:23

本文关键词：辽东湾中部晚第四纪沉积物物源与沉积环境:来自碎屑矿物和自生黄铁矿的证据　出处：《海洋地质与第四纪地质》2016年02期 　论文类型：期刊论文

【摘要】：对渤海辽东湾LDD7岩心的沉积物样品进行了碎屑矿物鉴定,分析了岩心轻重矿物组合、粗颗粒沉积物物质来源、碎屑矿物特征指数及氧同位素3期渤海相对海平面位置。结果表明,轻矿物是以石英和长石为主的组合,片状矿物和碳酸盐矿物次之;重矿物是以角闪石类、绿帘石类、云母类和自生黄铁矿为主的组合,其次为金属矿物、石榴子石和榍石等。岩心为多源沉积,物质主要来源于辽河、滦河和黄河等中大型河流的入海沉积物。碳酸盐矿物作为黄河的特征矿物,指示黄河对岩心低海平面时期的沉积层影响较大。石英/长石比值、极稳定矿物ZTR指数和磷灰石ATi指数之间具有一定的对应性,能够大致反映流域的风化程度,但在利用这些指数指示风化作用时不能忽视物源对它们的影响。与还原环境密切相关的自生黄铁矿在水动力较弱且富含有机质的河漫滩、湖泊相和潮滩相中含量高。渤海岩心中氧同位素3期沉积物的年代和距现代海平面深度投点整体位于全球海平面上方,考虑到沉积环境水深、构造沉降和沉积物压实等因素,渤海相对海平面位置高于全球平均海平面。
[Abstract]:The clastic mineral identification of sediment samples from LDD7 core in Liaodong Bay of Bohai Sea was carried out. The light and light mineral assemblage of core and the source of coarse grain sediment were analyzed. The characteristic index of clastic minerals and the relative sea level position of Bohai Sea in the 3rd stage of oxygen isotope. The results show that the light minerals are mainly composed of quartz and feldspar, followed by flake minerals and carbonate minerals. The heavy minerals are composed of amphibole, verdant, mica and authigenic pyrite, followed by metal minerals, pomegranate and sphene. Carbonate minerals are the characteristic minerals of the Yellow River, indicating that the Yellow River has a great influence on the sedimentary layer in the low sea level period of the core and the ratio of quartz to feldspar. The ZTR index and apatite ATi index of extremely stable minerals have some correspondence, which can roughly reflect the weathering degree of the basin. However, the influence of provenance on them should not be ignored when these indices are used to indicate weathering. Autogenic pyrite, which is closely related to the reducing environment, is in the floodplain where hydrodynamic is weak and rich in organic matter. The age and depth of oxygen isotopic sediments in the core of the Bohai Sea are all located above the global sea level, taking into account the water depth of the sedimentary environment. The relative sea level of Bohai Sea is higher than that of the global average sea level due to tectonic subsidence and sediment compaction.
【作者单位】：国土资源部海洋油气资源与环境地质重点实验室中国地质调查局青岛海洋地质研究所;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;山东理工大学资源与环境工程学院;
【基金】：国家自然科学基金项目(41406074;41476052) 辽东湾近海海砂及相关资源潜力调查(1212011088110)
【分类号】：P736.21
【正文快照】： 辽东湾位于渤海北部,是一个西、北、东三面被辽宁省包围,仅南面与渤海相通的半封闭海湾,在构造上处于渤海盆地辽东湾坳陷,地形从湾顶及两岸向中央倾斜,东侧水深大于西侧。沉积作用受海洋和陆地各种自然过程共同影响,沉积物记录了海平面、沉积环境、入海沉积物和气候变化等丰富

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