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  

LATE QUATERNARY SEDIMENT PROVENANCE AND PALAEOENVIRONMENT IN LIAODONG BAY,BOHAI SEA:EVIDENCE FROM DETRITAL MINERALS AND AUTHIGENIC PYRITE

作　　者：王利波[1,2] 李军[1,2] 赵京涛 胡邦琦[1,2] 窦衍光[1,2] 孙荣涛[3] 

机构地区：[1]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,青岛266071 [2]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,青岛266071 [3]山东理工大学资源与环境工程学院,淄博255049

出　　处：《海洋地质与第四纪地质》2016年第2期39-48,共10页Marine Geology & Quaternary Geology

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)

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。Detrital minerals of a 50.1m-long sediment core（LDD7）from the Liaodong Bay（LDB）,the Bohai Sea were analyzed to investigate light/heavy mineral assemblages and sediment provenance of the sediments,chemical weathering extent of drainage basin surrounding the LDB,and relative sea-level of the Bohai Sea in Marine Isotope Stage（MIS）3.Major light mineral components are quartz and feldspar;plateshaped minerals and carbonate minerals come the second.Among heavy minerals,amphibole,epidote,mica group and authigenic pyrite occupy the first place;metal minerals,garnet and sphene take the second place.Coarse components of the core come from multiple sources,which mainly include the discharges from the Liaohe,Luanhe and Huanghe Rivers.As the characteristic minerals of the Huanghe River,the abundance of carbonate minerals indicate that the Huanghe River greatly influenced the core during the low sea-level stages.Ratio of quartz/feldspar,ZTR index of the very stable heavy minerals and ATi index of the apatite,which are correlated to each other to some extent,can roughly reflect the chemical weathering extent of the drainage basin.However,the impact of sediment source on these indexes should not be ignored.Authigenic pyrite,which correlates with a reducing environment,is concentrated in alluvial flat,lacustrine and tidal flat facies with low hydrodynamic force and enriched organic matter.Considering that the scatter points of age versus depth of cores from the Bohai Sea are distributed above the average relative sea-level curve of the world during MIS 3,together with the considerations of depositional water depth,tectonic subsidence and sediment compaction,relative sea-level of the Bohai Sea maybe higher than the world sea-level in MIS 3.

关 键 词：碎屑矿物 沉积物物源 化学风化 海平面 辽东湾 

分 类 号：P736.22[天文地球—海洋地质]