台湾海峡表层沉积物中重矿物特征及其物质来源   总被引：15，自引：0，他引：15  

陈华胃 《台湾海峡》1993,12(2):136-144

台湾海峡重矿物平均分布0.95%,其分布由西岸向东岸递减;由北部经台湾浅滩朝粤东方向缓慢递减。碎屑矿物46种,以角闪石、绿帘石、磁铁矿、钛铁矿、褐铁矿和片状矿物为主,它们占重矿物含量的67%。据主要重矿物含量将海峡分成8个矿物组合区。碎屑矿物来自海峡两岸基岩,通过河流搬运入海,有部分片状矿物为海峡以北的物质随浙闽沿岸流进入海峡而沉积。其海绿石是台湾西岸、澎湖岛第三系或第四系含海绿石岩层剥蚀后搬运入海沉积而成的。台湾浅滩的残留沉积物为晚更新世低海面时期的河口滨海相沉积物。由于处在开放的海洋环境,至今没有接受现代沉积。残留沉积物中的磁铁矿、钛铁矿、锆石等重矿物相对富集,含量高于近源海域,有可能赋存浅海砂矿。  相似文献   

东海西湖凹陷保俶斜坡下第三系储层岩石学特征     

蒲庆南  杨宝星 《海洋地质前沿》1994,(6):7-8

东海西湖凹陷保俶斜坡下第三系储层砂岩为长石岩屑砂岩或岩屑长石砂岩，杂基含量小于5％，矿物成分主要为伊利石和绿泥石；胶结物主要成分为高岭石、石英次生加大边、碳酸盐矿物，总含量小于10％．  相似文献   

北部湾VI钻孔岩芯的重矿物组合研究   总被引：2，自引：0，他引：2       下载免费PDF全文

陈丽蓉  张秀荣 《海洋科学》1993,(2):35-38

本文对北部湾XI钻孔岩芯中各种沉积相中的重矿物组合分别作了研究,结果表明,在湖相沉积物中自生黄铁矿物含量高,滨海相沉积物中稳定矿物(钛铁矿、电气石、锆石)特别富集,浅海相沉积物中则出现大量的自生海绿石,由此说明,重矿物组合的研究对阐明沉积相是有其重要意义的。  相似文献   

Characteristics of Clay Minerals in the Northern South China Sea and Its Implications for Evolution of East Asian Monsoon since Miocene   总被引：3，自引：0，他引：3  

万世明  李安春  胥可辉  尹学明 《中国地质大学学报(英文版)》2008,19(1):23-37

Clay mineral assemblages, crystallinity, chemistry, and micromorphology of clay particles in sediments from ODP Site 1146 in the northern South China Sea (SCS) were analyzed, and used to trace sediment sources and obtain proxy records of the past changes in the East Asian monsoon climate since the Miocene, based on a multi-approach, including X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDS). Clay minerals consist mainly of illite and smectite, with associated chlorite and kaolinite. The illite at ODP Site 1146 has very well-to-well crystallinity, and smectite has moderate-to-poor crystallinity. In SEM the smectite particles at ODP Site 1146 often appear cauliflower-like, a typical micromorphology of volcanic smecites. The smectite at ODP Site 1146 is relatively rich in Si element, but poor in Fe, very similar to the smectite from the West Philippine Sea. In contrast, the chemical composition of illite at ODP Site 1146 has no obvious differences from those of the Loess plateau, Yellow River, Yangtze River, and Pearl River. A further study on sediment source indicates that smectite originates mainly from Luzon, kaolinite from the Pearl River, and illite and chlorite from the Pearl River, Taiwan and/or the Yangtze River. The clay mineral assemblages at ODP Site 1146 were not only controlled by continental eathering regimes surrounding the SCS, but also by the changing strength of the transport processes. The ratios of (illite+chlorite)/smectite at ODP Site 1146 were adopted as proxies for the East Asian monsoon evolution. Relatively higher ratios reflect strongly intensified winter monsoon relative to summer monsoon, in contrast, lower ratios indicate a strengthened summer monsoon relative to winter monsoon. The consistent variation of this clay proxy from those of Loess plateau, eolian deposition in the North Pacific, planktonic, benthic foraminifera, and black carbon in the SCS since 20 Ma shows that three profound shifts of the East Asian winter monsoon intensity, and aridity in the Asian inland and the intensity of winter monsoon relative to summer monsoon, occurred at about 15 Ma, 8 Ma, and the younger at about 3 Ma. The phased uplift of the Himalaya-Tibetan plateau may have played a significant role in strengthening the Asian monsoon at 15 Ma, 8 Ma, and 3 Ma.  相似文献   

矿物材料学的内涵与特征   总被引：3，自引：2，他引：1  

汪灵 《矿物岩石》2008,28(3)

经过20余年的研究与发展,矿物材料学已经成为材料科学与工程中一个相对独立和完善的组成部分,由于其定义、内涵与特征等基本问题与材料科学的从属性和独特性,多年的研究认为:矿物材料学是研究矿物材料的组成与结构、制备与合成、性能和使用效能以及矿物原料性质与特点等五要素及其相互关系和规律的一门学科.这五要素是具有内部互相联系和作用的有机整体,研究这五要素并了解它们之间的相互关系和规律构成了矿物材料学的内涵.矿物原料性质与特点是其他四要素的基本前提或重要基础,矿物原料及其与其他四要素的关系以及矿物在其他四要素中的关键性都体现了矿物材料学的矿物科学属性,正是因为兼具材料科学属性和矿物科学属性的矿物材料学这一重要特征使其有别于其他学科,而具有了理论及实用价值.  相似文献   

长江流域河水和悬浮物的锂同位素地球化学研究   总被引：9，自引：1，他引：8  

汪齐连  刘丛强  赵志琦  丁虎 《地球科学进展》2008,23(9):952-958

深入理解流域侵蚀过程中的锂同位素分馏对于运用锂同位素来示踪化学循环和气候变化是十分必要的。研究集中在长江干流和主要支流的水体和悬浮物的锂及锂同位素组成。长江流域水体的锂及锂同位素组成（δ⁷Li）分别为150~4 570 nmol/L和+7.6‰~+28.1‰,两者沿上游至下游的变化趋势相反。悬浮物锂同位素组成（δ⁷Li）变化比较稳定,分别为41~92 μg/g和-4.7‰~+0.7‰,而且总是低于相应水体的锂同位素组成。悬浮物和流体之间的锂同位素分馏系数在0.977和0.992之间,与悬浮物的量及组成存在明显相关性,反映了粘土矿物的吸附和化学风化的程度。锂含量与锂同位素组成之间良好的负相关性表明流域水体的锂来自2个端元混合：其一可能是蒸发盐岩,并伴有深部热泉水;其二可能是硅酸岩。  相似文献   

南堡凹陷油田古近系碎屑重矿物的物源和构造意义   总被引：2，自引：1，他引：1  

董月霞  张宁  周海民  夏文臣 《地质科技情报》2008,27(5)

利用石油钻井岩心,在南堡凹陷古近纪地层中采集了52件砂砾岩样品并进行了重矿物定量分析.重矿物组合的垂向变化指示出了3个碎屑重矿物组合段,它充分展现了物源区多阶段隆升-剥蚀的历史:始新世的沙三至沙二组合段为凹陷基底岩石层圈(以花岗片麻岩为主)的隆升-剥蚀过程;始新世沙-至渐新世的东二组合段为更深层变质岩层圈的隆升-剥蚀过程;渐新世末的东-段为稳定和老化的变质层圈的隆升-剥蚀及物源区调整过程.在石油勘探井较密且分布较广的东-段,系统进行了各类碎屑扩散体系的重矿物分析,区分出了4个碎屑重矿物扩散体系,分别来自两种构造类型的物源区:①扇三角洲和辫状河三角洲前浊积扇体系物源区为燕辽古造山带,重矿物分布模式表现为主蜂左偏、重矿物组分较少、稳定重矿物显示度偏低的特点;②两个河控三角洲体系物源区为华北古克拉通,重矿物分布模式表现为对称的主峰、重矿物组分较多、稳定组分显示度偏高的特点.  相似文献   

基于矿物学方法评价浙江省土壤中Pb污染状况     

郑喜珅  鲁安怀  汪庆华  郑佳  朱朝晖  于芳 《地质科技情报》2008,27(3):77-82

利用土壤重金属元素环境质量矿物学评价方法,对淅江省全境土壤中不同土壤类型(或亚类)表层、不同母质表层和剖面中的Pb进行环境质量评价的结果表明,土壤中Pb的实测量和土壤对Pb的固持量决定了土壤中Pb的环境质量,浙江省土壤中Pb的污染度有正负值,说明土壤中的Pb对有些地区产生了污染,而对有些地区则没有产生污染.研究结果揭示,土壤矿物对Pb具有一定的固定与容纳能力,超过其固定与容纳能力,土壤中的Pb会对环境造成污染.这一旨在揭示土壤中重金属元素与各种矿物之间环境平衡关系的方法,可为评价土壤环境质量提供科学依据和技术支撑.  相似文献   

Distribution of Palygorskite in the Lingtai Profile of Chinese Loess Plateau: Its Paleoclimatic Implications     

XIE Qiaoqin  CHEN Tianhu  Chen Jun  Ji Junfeng  XU Huifang  XU Xiaochun 《《地质学报》英文版》2008,82(5):967-974

Palygorskite is a typical indicator mineral of the arid and strong evaporation environment. Distribution of palygorskite in loess-red clay sequences may act as an important indicator for reconstruction of the paleoenvironment and paleoclimate. In this paper, field emission scanning electron microscope and high-resolution transmission electron microscope observations on the red clay-loess-paleosol of the Renjiapo profile at Lingtai, Gansu Province indicate that palygorskite occurs widely in red clay sequences formed before 3.6 Ma, but no occurrence has been found in eolian sediments since 3.2 Ma. Micromorphological features and microstructure of palygorskite show that it is an autogenic mineral formed during pedogenesis, and transformed from iilite-montmorilionite under the pore water action. In the Lingtai profile, the disappearance horizon of palygorskite is consistent with those of increasing magnetic susceptibility, dust flux and depositional rate. The distribution of palygorskite in the profile indicates that the interval of around 3.6 Ma was an important transformation period of the East Asian paleomonsoon, when changes took place in the East Asia paleoclimate pattern, i.e. a high-frequency strong fluctuation alternative evolution of the environment. Therefore, palygorskite is a key indicator mineral of the East Asian paleomonsoon evolution of that time.  相似文献   

Multifractal Analysis of Element Distribution in Skarn-type Deposits in the Shizishan Orefield, Tongling Area, Anhui Province, China   总被引：3，自引：1，他引：2  

Wang Qingfei  Deng Jun  Wan Li  Zhao Jie  Gong Qingjie  Yang Liqiang  Zhou Lei  Zhang Zhijun 《《地质学报》英文版》2008,82(4):896-905

A series of element concentrations sampled from four drill cores with a length about 1000 m into different skarn-type deposits were selected from the Shizishan orefield, central Tongling, southeastern part of Anhui Province. Using the multifractal method, the distribution and migration characteristics of the major and trace elements are analyzed. The multifractal spectrum of the major elements is left-skewed, whereas the spectrum of the trace elements is right-skewed, which shows that in the process of skarn formation, the trace elements were enriched only locally, and major elements transported within a much larger range. The correlation coefficients of the multifractal parameters Aa （width of the multifractal spectrum） of the four drill cores are relatively low, but the correlation coefficients of the multifractal parameters R （spectrum symmetry parameter） and Af are relatively higher, indicating that although the non-homogeneous intensity of the distribution of elements is inconsistent, their spatial accumulation patterns are almost the same during the ore-forming process. The statistics of the mnltifractal parameters of various elements in the different locations show that the ore-forming processes and element migration pattern in the Shizishan orefield are consistent, and that the migrations of trace elements and major elements exhibit some differences.  相似文献