Manganese metalliferous sediments of the Deryugin Basin (Sea of Okhotsk): Chemical composition and geological setting     

A. S. Astakhov  V. V. Sattarova  A. I. Svininnikov  N. V. Astakhova  M. M. Domanov  M. V. Ivanov 《Russian Journal of Pacific Geology》2007,1(5):418-434

This paper reports the results of an investigation of the chemical composition and distribution of manganese-rich metalliferous sediments in the Deryugin Basin. They compose an upper sedimentary layer up to 30 cm thick within a strip up to 40 km wide and 180 km long in the central part of the basin along the East Deryugin suture zone bounding the Deryugin sedimentary basin to the east. The sediments are enriched relative to the regional background composition in Mn (by a factor of 35); Au; Ni; Zn; Co (by a factor of 3–5); and, locally, in Mo, V, Ba, Cu, Pb, and Hg. It was supposed that their formation was controlled by several processes: precipitation of Mn and some other trace elements from hydrothermal plumes of seawater that occasionally form above submarine hot vents in the northern part of the basin, precipitation from anoxic bottom waters at the eastern boundary of the Deryugin sedimentary basin, and early diagenetic migration of Mn into the surface sediments.  相似文献   

黄河西霞院工程坝基黏土岩的工程地质特性研究     

刘汉东  戴菊英  李继伟 《岩土力学》2006,27(11):2045-2049

黄河西霞院工程电站厂房地基为上第三系洛阳组黏土岩类地层。现场勘察揭示该黏土岩具有特殊的工程地质性质,在开挖或遇水时风化分解较快,由岩石的性质转变为土的性质。为了更好地了解洛阳组黏土岩的工程特性,进行了一系列室内试验和现场大型剪切试验。该黏土岩的黏土含量最高达53.7 %,黏土矿物成分以蒙脱石为主,含量在28 %～38 %,岩体的膨胀率为0.6 %～4.9 %,单轴抗压强度为0.11～1.04 MPa,凝聚力为132.2 kPa,内摩擦角为22.29°。研究表明洛阳组黏土岩具有典型的软岩硬土特征。  相似文献   

泥岩蠕变行为的实验研究及其描述   总被引：14，自引：1，他引：13  

万玲  彭向和  杨春和  郭开元 《岩土力学》2005,26(6):924-928

利用自行研制的岩石三轴蠕变仪,对泥岩进行了系统的三轴蠕变试验。试验中考虑了轴压σ1和围压σ3对蠕变的影响。结果表明,当围压σ3一定时,轴向应力σ1增加,蠕变加快,在稳态蠕变阶段的应变率增大,试件的寿命缩短。而当应力差?σ=σ1–σ3保持不变时,围压σ3增加,蠕变减慢,稳态蠕变阶段的应变率也减小,试件的寿命增加。利用非经典粘塑性损伤本构模型对试验现象进行了分析,得到了较为满意的结果。  相似文献   

贵州大方地区粘土岩成因探讨     

邓春涛  林世伟  朱兴波 《四川地质学报》2012,(4):408-411

大方庆阳煤矿区龙潭煤系和茅口灰岩界限粘土岩分析结果表明:该层粘土岩为黄铁矿质高岭石粘土岩,对其化学成分中Na2O、K2O、MgO、CaO和Pb的研究认为,该层粘土岩是在安静低能、酸性介质还原环境下,为受峨眉山玄武岩影响的火山事件沉积粘土岩。  相似文献   

Fundamental aspects of the hydromechanical behaviour of Callovo-Oxfordian claystone: From experimental studies to model calibration and validation     

《Computers and Geotechnics》2017

  相似文献   

山西大同小峪煤矿煤系粘土岩夹矸地球化学特征   总被引：1，自引：0，他引：1  

王水利  梁绍暹 《煤田地质与勘探》2011,39(6):6

采用化学法和中子活化(INAA)法,对山西大同小峪煤矿山西组和太原组的3件不同粘土岩样品的8种常量元素(氧化物)和33种微量元素含量进行了测定。通过对具有示踪意义的元素及其比值的对比分析表明,3个样品总体上均不具有典型的沉积岩特征,应该是由酸性或酸性偏碱性火山物质(降落的或陆源搬运的)在地表覆水较浅的弱氧化条件下经原地淋滤、蚀变形成的。岩石总体蚀变程度较高,不稳定或较不稳定的元素大量流失,甚至一些较稳定的元素(如高岭岩中的铁、锰)也明显流失。蚀变环境及介质条件、成岩原始物质组成及其粒度大小以及粘土物质组成是造成粘土岩类型及其不同类型间元素含量差异的主要原因。   相似文献   

Tausonite and aluminum-fluorine titanite from the metamorphosed metalliferous sediments of the Triassic chert formation of the Sikhote Alin     

E. V. Perevoznikova  N. V. Miroshnichenko 《Russian Journal of Pacific Geology》2009,3(3):294-297

Rare strontium mineral tausonite and a peculiar Al- and F-rich titanite variety were found in the metamorphosed metalliferous sediments of the Triassic chert formation of the Sikhote Alin, which are distinguished by the abundance of native elements, intermetallic compounds, and metal solid solutions, as well as the presence of diverse Au, Ag, and PGE minerals. Tausonite was documented in the manganese (metamorphosed siliceous-rhodochrosite) rocks of the Ol’ga mining district and in the “brown cherts” (siliceous rocks with manganese garnet and spessartine) of the Dal’nerechensk district, Primorye. It forms rather numerous grains 2–10 μm across usually occurring as inclusions in quartz or rhodonite. According to the electron microprobe analysis, in addition to Sr, Ti, and O, the mineral contains only Fe³⁺ (up to 0.20 a.f.u.). Aluminum-fluorine titanite was found in the “brown cherts” of the Dal’nerechensk district of Primorye (upper reaches of the Gornaya River). Its crystals are up to 200 × 200 μm in size. The recalculation of the microprobe analyses to crystal chemical formulas indicated that up to half of the Ti sites in the structure of this mineral may be occupied by Al. The decrease of the total positive charge owing to the Al³⁺ substitution for tetravalent Ti⁴⁺ is compensated for by a decrease in the total negative charge owing to F^? substitution for O^2? via the scheme Al³⁺F^? → Ti⁴⁺O^2?. The occurrence of considerable amounts of F substituting for oxygen in the titanite structure and, as a consequence (owing to the crystal chemical features of the mineral), the high Al content were related to the reduced character of the metamorphism of the metalliferous deposits.  相似文献   

屏障效应对生物地球化学异常形成的影响及找矿有效指示植物的选择     

宋慈安  雷良奇  杨仲平  文宗振 《地质科技情报》2012,31(1):1-8

采用光谱仪及透射电子显微镜对广西几个金属矿床的生物地球化学异常和植物细胞微观特征进行了研究,结果发现:生物地球化学异常对土壤地球化学异常有明显的物质性继承关系;生物地球化学异常的物质以金属聚集体(电子致高密度体物质)的形式沉淀在植物液胞中或细胞壁及膜边缘,其对植物的伤害可能只达到细胞或组织的水平.生物地球化学异常的形成...  相似文献   

东太平洋海隆(EPR) 13°N 附近含金属沉积物孔隙率研究     

武力  曾志刚  殷学博  王晓媛  陈帅 《海洋科学》2012,36(1):81-86

研究了采自东太平洋海隆13°N(EPR 13°N)的一个热液成因含金属箱式沉积物岩心E272的孔隙率变化特征。样品孔隙率在70.0%-85.2%之间,顶部层位比底部层位高14%左右。孔隙率随深度增加而指数式单调递减,平均递减梯度约为-0.31%/cm。该岩心上部层位呈红棕色,下部层位呈黄绿色,表明该岩心经历了显著的早期化学成岩作用。前人关于该岩心的元素地球化学,粒度和年代学数据,共同证明该岩心孔隙率随深度变化特征受稳态压缩过程控制。其孔隙率随深度的变化关系符合稳态压缩模型的经验拟合公式。E272顶部沉积物-水界面处溶解物质与海水的交换以离子扩散机制为主,而岩芯内部溶解物质的迁移则可能主要受自下而上的孔隙水流动机制控制,这与岩芯中活动元素含量上部高,下部低的分布模式一致。该研究对将来进一步讨论E272岩心在早期成岩作用中的化学过程具有指导意义。  相似文献   

内蒙古苏宏图地区黏土岩矿物组成与地球化学特征     

邱晓兵  刘平辉  刘晓东 《江苏地质》2019,43(2):253-262

为探究内蒙古苏宏图地区黏土岩的地球化学特征、沉积物质来源和构造环境,利用多晶X射线衍射（XRD）和ICP-AES/MS分析法对苏宏图地区SZK-2井20件黏土岩岩芯样品进行分析测试。结果表明：XRD分析显示苏宏图地区黏土岩中黏土矿物组成以伊利石为主,伊利石质量分数平均值为37.64%;与大陆上地壳相比,黏土岩相对富集SiO2、Al2O3、Zr、As,贫P2O5、MgO、MnO、Cr、Ni,两者的K2O、TiO2、Sr、Ba含量接近。黏土岩中稀土元素特征为轻稀土元素富集,重稀土元素相对亏损,表现为明显的右倾,出现明显的Eu（平均值=0.60）负异常和Ce（平均值=1.01）轻微负异常,与大陆上地壳稀土元素的配分模式较为相似;K2O/Na2O-SiO2和微量元素构造背景判别图解中,样品多数落在大陆岛弧区,少量落在活动大陆边缘,反映了苏宏图地区沉积时期的物源来自于上地壳长英质物源且形成于大陆岛弧的构造背景中。  相似文献