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1.
本文分析了采自南极长城湾、阿德雷湾的21个粘土矿物样品。X射线衍射分析、差热分析及化学分析表明,海区粘土矿物主要由蒙脱石(51~70%)、蒙脱石—伊利石、蒙脱石—绿泥石混层矿物(23~65%)、伊利石(16~42%)、绿泥石(7~17%,含蛭石)及高岭石(4~18%)组成。粘土矿物的分布,在长城湾内,以蒙脱石—伊利石混层矿物为主,在长城湾湾口区,则以蒙脱石为主。显然,这一特征受到物质来源及海湾地形的影响。海湾区粘土矿物主要来自毗连陆地玄武岩类的风化产物,伊利石主要来自邻近海域,以蒙脱石及其混层矿物为主的组合及其化学组成表明,海湾邻近陆地曾经历过较强的化学风化作用阶段。  相似文献   

2.
南海北部海域粘土矿物分布特征   总被引:2,自引:0,他引:2  
南海北部海域海底沉积物中的粘土矿物组分为伊利石、绿泥石、高岭石、蒙脱石和混层矿物,根据粘土矿物在该海域的分布规律和海底地形、水动力条件、沉积作用等特征可划分为三种类型的粘土矿物区.从粘土矿物组合类型可知,该海域粘土矿物主要来源于我国大陆.南部深海区的粘土矿物除了来自北部大陆外,菲律宾火山岛弧和南面马来西亚携带来的高岭石也是深海区粘土矿物的来源之一.而116°E以西海域,绿泥石向深海方向增加可能与末次冰期珠江古河道携带的残留绿泥石和高岭石向绿泥石转变有关.海底火山是黄岩岛附近海域蒙脱石和绿泥石增高的原因之一.从整个海域粘土矿物分布格局可知,该海域的粘土矿物组合类型主要受源区气候和周围的陆源岩石类型所控制.  相似文献   

3.
马里亚纳海槽区粘土矿物组成及分布特征   总被引:2,自引:0,他引:2  
根据7个岩芯粘土矿物的研究,马里亚纳海槽晚更新世以来的沉积物中主要粘土矿物是蒙皂石,其次是少量FeMg绿泥石和伊利石,蒙皂石和FeMg绿泥石主要是海底基性火山物质蚀变形成的自生矿物,伊利石主要是来自海槽北面和西北面陆上岩石的风化产物,蒙皂石由海槽北部向南部呈增加趋势,而伊利石则呈减少趋势,此外,在距今大约45-10kg形成的地层中蒙皂石呈减少趋势,伊利石则呈增加趋势,上述粘土矿物组成及分布主要与物  相似文献   

4.
严肃庄  曹沛奎 《台湾海峡》1997,16(2):128-134
采用实体显微镜、偏光显微镜及X射线衍射仪对三沙湾表层沉积物中的重矿物和粘土矿物进行鉴定和研究。已鉴定出的重矿物有20余种,其含量以磁铁矿、赤铁矿、绿帘石和角闪石等为高,锆石、黄铁矿等次之。根据三沙湾重矿物的含量与特征,划分为三个组合类型。粘土矿物是以伊利石为主,绿泥石、高岭石为次,蒙脱石含量少的组合。综合矿物的种种特征,作者认为三沙湾表层沉积物中的粗颗粒物质主要是由径流从陆上流域带入的,细颗粒物质  相似文献   

5.
渤海表层沉积物中的粘土矿物   总被引:4,自引:1,他引:4  
何良彪 《海洋学报》1984,6(2):272-276
对渤海30多个表层样作了粘土矿物分析,结果表明,广泛存在的粘土矿物是伊利石、高岭石、绿泥石和蒙脱石.伊利石为优势矿物,平均含量为60%;次之为高岭石,平均18%;绿泥石与蒙脱石为次要矿物,平均都在10%左右.渤海粘土矿物在表层沉积物中的分布图式受物源控制,其中黄河的入海泥沙影响最大.海区的水动力特征与地球化学环境(如盐度)也是影响粘土矿物分布的重要因素.根据粘土矿物的分布与组合特征,可将渤海划分为两个矿物省:辽东湾矿物省与渤海湾-莱洲湾矿物省,而这后一个矿物省明显地反映了黄河泥沙入海后的运移、扩散与沉淀的特征,这对渤海沉积物来源的研究以及了解黄河三角洲的形成过程与对它的开发利用都是有意义的.  相似文献   

6.
末次间冰期兰州黄土记录中的粘土矿物及其环境意义探讨   总被引:21,自引:2,他引:21  
本文研究了末次间冰肮分辨率兰州黄土(S1)21个样口的粘土矿物,并与现代尘暴沉积物作了对比。研究结果表明,S1三个古土壤导春间所夹两个黄土层中的粘土矿物组合特征基本一致,以伊利石为主,其次为绿泥石和高岭石及少量伊/蒙间层矿物。粘土矿物的形成以碎屑成因为主,其一在剖面上的变化具有批示气候变化的意义。古土壤层中伊利石结晶度较黄土层中低,反映在气候温暖潮湿的条件下粘土矿物受到了不同和蔼的改造。粘土矿物总  相似文献   

7.
采用X射线衍射(XRD)分析技术分析了长江水下三角洲地区65个表层沉积物样品的粘土矿物。结果表明,长江水下三角洲粘土矿物主要由伊利石、绿泥石、高岭石和蒙皂石构成;长江水下三角洲亚环境粘土矿物组成则不同,三角洲前缘亚环境中高岭石和绿泥石的平均含量高于前三角洲的含量,而前三角洲亚环境中伊利石和蒙皂石的平均含量高于三角洲前缘的含量。研究区粘土矿物主要来自长江流域,属于长江源,其分布主要受沉积动力环境和粘土本身性质的制约。  相似文献   

8.
根据7个岩芯粘土矿物的研究,马里亚纳海槽晚更新世以来的沉积物中主要粘土矿物是蒙皂石,其次是少量FeMg绿泥石和伊利石.蒙皂石和FeMg绿泥石主要是海底基性火山物质蚀变形成的自生矿物,伊利石主要是来自海槽北面和西北面陆上岩石的风化产物.蒙皂石由海槽北部向南部呈增加趋势,而伊利石则呈减少趋势.此外,在距今大约45ka~10ka形成的地层中蒙皂石呈减少趋势,伊利石则呈增加趋势.上述粘土矿物组成及分布主要与物质来源、火山活动、海底浊流以及古气候变化的影响有关.  相似文献   

9.
中太平洋调查区沉积粘土矿物   总被引:2,自引:0,他引:2  
通过用X射线衍射仪等手段的分析鉴定,确认该区的主要粘土矿物为伊利石、蒙脱石、高岭石、绿泥石。蒙脱石在钙质软泥中含量低,在红粘土中含量高,伊利石含量与蒙脱石相反。经综合分析得出两粘土矿物分区。影响粘土矿物分布的主要因素是物质来源。  相似文献   

10.
南海粘土矿物组合特征及其环境意义   总被引:1,自引:0,他引:1  
利用X射线衍射法(XRD)对南海12个海底表层沉积物和20个悬浮物样品中粘土矿物组成和分布特征进行了综合分析。结果表明:(1)研究区的表层沉积物粘土矿物以伊利石为主,其次为绿泥石、高岭石、伊/蒙间层矿物以及蒙皂石;悬浮物粘土矿物是以绿泥石为主,其次为高岭石、蒙皂石、伊利石以及伊/蒙间层矿物。(2)粘土矿物的组成和分布特征主要受气候条件、物质来源、水动力条件及相互间稀释作用的制约。伊利石的含量随离岸距离和水深的增加呈增大趋势;高岭石则在近岸区特别是河口区富集;绿泥石在西部沿岸海区的含量较低,在东部岛弧和北部台湾岛附近海区的含量较高;蒙皂石与火山作用密切相关,在东部火山岛弧附近海区含量较高。(3)粘土沉积物的来源以河流输入为主,海洋自生和风尘搬运对该区的沉积影响不大。(4)深海悬浮物粘土矿物的组成变化能够很好地指示短尺度气候环境的变迁,伊利石的结晶程度对气候和环境变化反映灵敏,其随所处环境的压力增大而变差。  相似文献   

11.
The clay minearals are composed of illite, chlorite, kaolinite, montmorillonite and mixed-layer minerals in the submarine sediments of the northern South China Sea. Three types of clay mineral zone can be recognized on the basis of the distributive regularity of clay minerals, submarine relief, hydrodynamic conditions and depositional characteristics in this region. Apart from the northern mainland source, kaolinites carried from the Philippines volcanic arc in the east and Malaysia in the south are also assumed to be one of the sources of the clay minerals in the deep sea. The increase of chlorites to the abyssal direction in the west of 116° E might be associated with the residual chlorites carried from the ancient Zhujiang River during the glacial period and the conversion of kaolinite into chlorite submarine volcanoes appear to be one of the sources of the increment of montmorillonite and chlorite around the Huangyan Island. From the distribution pattern of clay minerals in the whole area, it is kn  相似文献   

12.
北极圈海域表层沉积物的黏土矿物特征及其环境意义   总被引:2,自引:0,他引:2  
应用X射线衍射(XRD)分析技术对北极圈海域15个表层沉积物的黏土矿物进行了研究。结合伊利石的结晶度指数综合分析了研究区黏土矿物的组成和分布特征及其物质来源、沉积环境和水动力条件。结果表明,北极圈海域研究区的黏土矿物以伊利石为主(33%),其次为伊/蒙间层矿物(25%)、绿泥石(23%)、高岭石(15%)以及蒙皂石(4%)。伊利石的开形指数(Ns)都比较小,大多在1~2之间,Ns的分布对物源有一定的指示意义。楚科奇海区具较弱的水动力条件,沉积环境较稳定;白令海具强烈的水动力条件,属于冲刷环境。认为北极圈海域研究区的黏土沉积物均有三方面来源,即河流输入、海洋自生和冰筏搬运物。  相似文献   

13.
The Wash is an area of extensive intertidal flat sedimentation. Samples were examined from the intertidal zone of deposition and also from areas that are probable sources of the sediments being deposited.The mineralogy of the clay fractions of the sediments is dominated by illite, mixed layer illite-montmorillonite, montmorillonite, kaolinite and chlorite with only minor amounts of quartz and calcite. There is no apparent difference in the qualitative nature of the clay minerals found in the sediments. There is also little or no significant variation in the relative proportions of the clay minerals in the modern intertidal flat sediments. However, variations are found between the relative proportions of clay minerals present in the probable source materials and the intertidal flat sediments.Evans (1965) proposed that the main sources of the intertidal sediments are via erosion of the floors of the North Sea and the Wash, and the exposed coasts of Lincolnshire and Norfolk. Whilst accepting these as primary sources, the clay mineral data indicate that erosion and redeposition of the intertidal flat material is a further important source of clay grade sediments.  相似文献   

14.
Analyses of clay mineralogy about 30 surface sediments indicate widespread occurrence of illite, kaolinite, chlorite and montmorillonite throughout the Bohai Sea. Illite is the most abundant mineral, averaging 60%, kaolinite, next to illite, is the most abundant one,averaging 18%. Chlorite and montmorillonite come second, averaging 12% and 10% respectively. The distributive patterns of clay minerals in the surface sediments are closely related to the suspended materials carried into the Bohai Sea, especially to those did by the Huanghe River, and to water dynamics in the area. Based on the distribution, the assemblages and the others of clay minerals, the Bohai Sea can be divided into two clay mineral regions, the Liaodong Gulf region and the Bohai-Laizhou Bay region.  相似文献   

15.
对于太平洋深海沉积物的研究虽有很久的历史(如1873-1876年“挑战者”号的科学考察),但对该区开展深入系统的岩石学和矿物学研究却是六十年代以后的事.随着研究手段的发展和进步,已积累了关于该区深海沉积物的大量资料.目前我国的海洋工作者也正在努力开展这方面的科学研究工作.  相似文献   

16.
DC-2孔柱状岩芯取样深度为48.6m,粘土矿物组分以伊利石为主,其次为绿泥石、高岭石和蒙脱石。岩芯共分6个粘土矿物组合层,参考Mn/Fe计算结果,0—29.46m为浅海相;33.42—33.46m为淡水相;38.44—38.46m为浅海相;44.0—48.06m为淡水相沉积。综合研究表明该沉积段出现二次海进和一次海退。  相似文献   

17.
The clay minerals in the 18 core samples collected from the northern, equatorial and southeastern Indian Ocean are illite, chlorite, montmorillonite and kaolinite. In the fraction finer than 2 in the surface layer (top to 5 cm deep) of each core, the relative abundance of clay minerals varies widely from area to area. Kaolinite possesses the maximum proportion of the clay mineral composition and chlorite has the minimum proportion.Kaolinite is particularly dominant in sediments near off the northwestern coast of Australia. In the factions finer and coarser than 2 of the surface layer, montmorillonite and kaolinite tend to be abundant in the fraction finer than 2, and chlorite and illite tend to be abundant in the fraction coarser than 2. In some cores, kaolinite-rich layers in sediments which are considered to have been transported by turbidity currents from the Bay of Bengal are found. Turbidity currents appear partly a role in transport of sediments to the equatorial Indian Ocean.As to the relation between the vertical change of clay mineral composition and geochronological data, montmorillonite and kaolinite tend to be more abundant in interglacial ages than in glacial ages, while illite and chlorite tend to exhibit opposite trend.Muscovite and biotite highly concentrated in the cores Ka-9 and Ka-15 collected from the equatorial Indian Ocean seem to originate from granite or gneiss of Ceylon and/or India.  相似文献   

18.
为探究闽江下游及河口区粘土矿物的含量分布特征,于2009年在该区域采集表层沉积物样品25个,利用X射线衍射进行了粘土矿物的含量测定.结果表明粘土矿物的相对百分含量范围分别为:高岭石(33%-47%,平均值为42%),伊利石(27%-43%,平均值为34%),绿泥石(20%-29%,平均值为24%),蒙脱石(0%-3%,平均值为1%).在显著水平为0.01时,伊利石与高岭石、绿泥石的含量呈显著负相关关系,伊利石与高岭石的相关系数为-0.825,伊利石与绿泥石的相关系数为-0.611.通过对闽江下游及河口区粘土矿物含量分布的分析及与中国近海的粘土矿物含量分布对比,闽江下游及河口区粘土矿物的含量分布受物质来源、地形条件、介质环境、粘土矿物自身颗粒大小形态和人类活动的影响.相对于黄河和长江,闽江表层沉积物中具有较高的高岭石含量,较低的伊利石含量,与珠江的粘土矿物组合特征类似,这反映出气候效应的影响.  相似文献   

19.
F.I Khalaf  M Ala 《Marine Geology》1980,38(4):331-348
The coast of the State of Kuwait is characterized by a relatively wide intertidal flat area. At the north, where it is close to Shatt-al-Arab estuary, the intertidal sediments are mainly fluviomarine, while open marine sediments dominate the southern intertidal flat area. Samples were examined from the intertidal zone of deposition from the fluviomarine and open marine environments.The sediments consist mainly of carbonate minerals (low-Mg calcite, high-Mg calcite, aragonite and dolomite), quartz, feldspars, clay minerals and heavy minerals. The mineralogy of the clay fractions of the sediments is dominated by illite, mixed-layer illite—montmorillonite, montmorillonite, chlorite, kaolinite and palygorskite with only minor amounts of quartz. Heavy minerals are concentrated in the very fine sand fraction and are dominated by opaque minerals, amphiboles, pyroxenes, epidotes, garnet, kyanite and sillimanite. Zircon, tourmaline, andalusite, staurolite and rutile are present in subordinate amounts.Three main sources are suggested for the intertidal sediments of Kuwait: (a) Shatt-al-Arab fluviatile deposits, (b) aeolian dust fallout, and (c) direct chemical and biogenic precipitation from the Gulf water.  相似文献   

20.
Abstract

This paper presents an experimental investigation into the effect of salinity on Atterberg limits, flowability, viscosity and strength properties of cement-stabilized clay minerals. Three groups of clay minerals (illite, kaolinite and montmorillonite) were obtained. Specimens with different porewater salinities were prepared by mixing the air-dried clays with sodium chloride (NaCl) at various salt concentrations (i.e., 0%, 2% 4%, 6% and 8%). Atterberg limits test results indicated that liquid limit and plasticity index decreased insignificantly with increasing salinity for Kaolinite and illite but significantly for montmorillonite. Flow test results indicated that of all specimens of three groups of clay minerals with or without adding cement consistently increase with increasing salinity. The flow value of montmorillonite increased more significantly than kaolinite and illite. Viscosity test results indicated that all the specimens tested behave as Bingham plastic. Flow value consistently decreased with increasing dynamic viscosity or yield stress, regardless of clay mineralogy, porewater salinity and cement amount. Strength test results indicated that all cement-stabilized specimens exhibit strain softening behavior. Unconfined compressive strength for three groups of clay minerals stabilized with cement consistently decreased with increasing salinity indicating that the presence of salt had an adverse effect on the development of strength.  相似文献   

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