短源河流碎屑矿物在河道、河口和海滩的组分变化及其控制因素——以山东半岛辛安河为例  

Component changes and control factors of detrital minerals in riverbed,estuary and beach of short source rivers:taking the Xin’an River in Shandong Peninsula as an example

作　　者：于健 金秉福 王孟瑶 王昕 Yu Jian;Jin Bingfu;Wang Mengyao;Wang Xin(Institute of Coast/School of Resources and Environmental Engineering,Ludong University,Yantai 246025,China;Institute of Estuary and Coastal Research/State Key Laboratory for Estuary and Coastal Research,East China Normal University,Shanghai 200062,China)

机构地区：[1]鲁东大学资源与环境工程学院/海岸研究所,山东烟台246025 [2]华东师范大学河口海岸科学研究院/河口海岸学国家重点实验室,上海200062

出　　处：《海洋学报》2023年第7期168-182,共15页

基　　金：国家自然科学基金(41576057)。

摘　　要：山东半岛诸多小河沉积物大多来源明确,矿物沉积分异相对较小,对其研究能为大河入海物源分析提供区域相似性,也可为黄、渤海陆架沉积提供山东半岛物质来源特征。本文以山东半岛东北部短源小河辛安河为例,对取自河床、河口、海滩的表层沉积样品的碎屑矿物分布规律进行了多粒级分析。研究表明,辛安河流域和海滩沉积物多为中砂和细砂,全样重矿物含量中等,在1.47%~8.19%之间。出现重矿物27种,轻矿物8种,主要重矿物为普通角闪石(41.7%)、绿帘石(16.7%)、阳起石(10.6%)和褐铁矿(6.7%),主要轻矿物为石英(49.0%)、斜长石(26.5%)和钾长石(20.7%),这些矿物的含量在河床、河口和海滩远高于其他碎屑矿物,且矿物组合保持不变,相对含量变幅不大;非主要矿物种类与碎屑粒径存在显著的非线性相关关系。辛安河矿物种类和含量受控于区域岩性物源,即酸性、中酸性侵入岩和区域变质岩。闪石族矿物在辛安河不同地貌中的相对稳定输出是其同宗同源属性所在,矿物组成变化主要受水动力控制下的粒度分选影响。山东半岛短源河流虽碎屑矿物种类和含量不尽相同,但它们来源于相似的地质地貌和岩石类型,矿物组成变化的主要控制因素为区域物源和粒度分选,其次为沉积环境差异。相比而言,黄河闪石族矿物的低含量、云母族和碳酸盐类矿物在特定粒级的高含量有别于半岛南北两侧的河源物质。Most of the small rivers in the Shandong Peninsula have clear sediment sources and relatively small mineral deposition differentiation,and their study can provide regional similarities for the analysis of the sources of large rivers into the sea,as well as the characteristics of the material sources in the Shandong Peninsula for the deposition of the Yellow Sea shelf and Bohai Sea shelf.In this paper,the distribution patterns of detrital minerals in surface sediment samples taken from riverbeds,estuaries and beaches were analysed at multiple grain levels,taking the Xin’an River,a small short-source river in the northeastern part of the Shandong Peninsula,as an example.The study shows that the Xin’an River basin and beach sediments are mostly medium and fine sands,with moderate heavy mineral content in the whole sample,ranging from 1.47%to 8.19%.Twenty-seven heavy minerals and eight light minerals occur,with the main heavy minerals hornblende(41.7%),chlorite(16.7%),actinolite(10.6%)and limonite(6.7%)and the main light minerals quartz(49.0%),plagioclase(26.5%)and potassium feldspar(20.7%),which are much more abundant than the other detrital minerals in the riverbed,estuary and beach,and the mineral assemblage remains constant,with less significant variation in relative content between them,while there is a significant non-linear correlation between non-dominant mineral species and clastic grain size.Mineral species and content in the Xin’an River are controlled by the regional lithological sources,i.e.acidic and moderately acidic intrusive rocks and regional metamorphic rocks,and the relatively stable output of amphibole group minerals across the different features of the Xin’an River is responsible for their homogeneity.The short source rivers of the Shandong Peninsula are derived from similar geological features and rock types,although the types and content of detrital minerals vary.The main controlling factors for mineral composition variation are regional sources and particle size sorting,followed by se

关 键 词：碎屑矿物 广粒径多粒级分析法 矿物分布 沉积环境 辛安河 山东半岛 

分 类 号：P736.212[天文地球—海洋地质]