成矿组分沉积同生富集的一种新机制:动态海水团的混合过程     

刘建明 《地球科学进展》1994,9(2):24-28

海洋可以被分成若干特征各异的、运动着的海水团，各种海洋现象就源于海水团的运动和相互作用。分隔不同海水团的前锋面上的混合作用是促使成矿组分发生沉淀富集的地球化学障。在海水团前锋混合带上，成矿组分在沉积物中产生同生富集，结果生成沉积矿床或矿源层。这是一种在时间上广泛发生但又尚未被人们所认识的崭新机制。  相似文献   

浙江杭嘉湖平原区土壤中营养元素丰缺状况的评价   总被引：5，自引：2，他引：5  

朱立新  周国华  任天祥  张连生  王徽  顾金秋  杜雄进  王成  蒋永平  周子泉 《物探与化探》1994,18(4):251-262

根据杭嘉湖平原区区域地球化学调查的结果,对本区土壤中农作物营养元素含量及有效量特征进行了评价研究。研究结果表明,本区土壤中营养元素除Mo、S含量表现缺乏外,其它元素为足量和丰富水平。不同土壤中营养元素有效量水平存在明显差异。在区域分布规律上,营养元素的含量及有效量随成土母质、成土过程和人类耕作等因素的不同而显示其差异特征。评价研究结果为本区农业生产中的合理区划、科学施肥、合理种植、土壤改良等提供了重要的地球化学依据。  相似文献   

扬子地块陡山沱期与梅树村期磷矿区域成矿规律   总被引：11，自引：1，他引：10  

东野脉兴 《化工矿产地质》2001,23(4):193-209

扬子地块是我国重要的产磷区 ,陡山沱与梅树村两大成磷期磷块岩储量占全国磷矿储量的85 %。在多年来丰富的资料积累与研究基础上 ,经过实践—理论—再实践的认识过程 ,归纳与提练出具有共性和普遍适用的海相磷块岩区域成矿规律 ,上升成为理性认识 ,因而具有很强的实用性 ,可作为成矿预测的准则。这些规律有 :含磷岩系规律、磷矿层规律、磷块岩自然类型规律、磷块岩结构类型规律、磷块岩矿物与化学成分规律、磷块岩序列规律、磷块岩成矿的构造古地理规律、陆缘坻含磷岩组规律、磷块岩富集规律等。并在此基础上划分出扬子地块的 2个三级成矿亚带和若干四级成矿区。  相似文献   

萃取富集-火焰原子吸收法测定碳酸钙中铅和镉     

黄俭惠  邱丽 《矿产与地质》2007,21(4):479-481

将碳酸钙试样用盐酸溶解后,在0.6mol/L的盐酸介质中,用KI-MIBK萃取试样中微量的铅和镉,有机相用原子吸收分光光度法测定。该方法测定铅的相对标准偏差为2.38%-6.31%,回收率为96.5%-97.0%;测定镉的相对标准偏差为4.50%-5.52%,回收率为96%-102.8%。结果可靠,具有灵敏、准确、快速、选择性好等优点。适用于碳酸钙中铅、镉的测定。  相似文献   

高碳黑色页岩型铂族元素矿床性探讨   总被引：6，自引：1，他引：6  

邢树文  孙景贵等 《地质与勘探》2002,38(6):17-21

简析了高碳黑色页岩型铂族元素矿床（PGED）的研究现状，并根据矿床的特征初步将该类矿床划分为中层状黑色页岩，薄层状黑色页岩和高碳构造岩型3类；并从形成环境，成因等方面对PGED形成进行了剖析，强调了源区供给，有机迁移和热液叠加作用的差异是导臻形成不同类型黑色含碳页岩型铂族元素矿床的根源，指出了我国贵州－湖南高碳黑色页岩型铂族元素成矿性较差与层薄和叠加温度低有关。  相似文献   

Anomalous Enrichment of Silver in Organic Matter of the Songxi Shale-hosted Ag-Sb Deposit in Northeastern Guangdong     

HU Kai  YU Chensheng  MA Dongsheng  ZHAI Jianping  ZHANG WenlanDepartment of Earth Sciences  Nanjing University  State Key Laboratoryfor Mineral Deposit Research  Nanjing University  Nanjing  XIAO Zhenyu Guangdong Nonferrous Metals Geological Exploration Bureau  Guangzhou Zhang Yuxu Zhu Xiling 《《地质学报》英文版》2002,76(2):249-256

The silver contents of organic matter in the host rocks of the Songxi shale-hosted Ag-Sb deposit of northeastern Guangdong, South China, have been directly determined using the electron microprobe technique. The silver contents in two types of organic matter, marine vitrinite and solid bitumen, vary in the range from 100×10-6to 350×10-6, which are from tens of times to thousands of times higher than those of the host rocks in the ore deposit. The average silver content of the organic matter is also several times higher than the pay grade of silver for commercial mining of the ore deposit. It is quite obvious that the organic matter of the host rocks in the ore district is characterized by an anomalous enrichment of silver. The results of this study indicate that the silver anomalies in the organic matter have been derived from both the host rocks and the silver-bearing fluids of the Songxi black shale ore source. In the course of sedimentation and later hydrothermal reworking, organic matter was able  相似文献   

内蒙古白乃庙金矿断裂构造控矿研究   总被引：5，自引：1，他引：5       下载免费PDF全文

和钟铧  周立宏等 《地质与勘探》2001,37(2):28-31

白乃庙金矿由石英脉型和蚀变岩型金矿组成，并受断裂及其破碎带控制，研究了白乃庙金矿断裂构造与成矿关系，断裂构造趋势面与找矿及矿体在断裂中的富集规律，并对成矿远景进行了预测。  相似文献   

内蒙古呼伦贝尔盟北部砂金矿成矿规律          下载免费PDF全文

张振强 《地质找矿论丛》2001,16(3):192-196

呼伦贝尔盟北部地区由于新构造运动含金地质体长期风化剥蚀，促使金的活化。河流及其2－3级支流发育，流域广，水流充足，有利于砂金矿的迁移、富集。现代的乐山丘陵、宽阔沟谷有利于砂金的保存。该区已发现数十个砂金矿，多为河谷型，主要含金层为含粘土砂层或砂砾层。砂金富集与河谷地貌关系密切，河床弯曲的凸岸、变异部位、关门咀、迎门山等地貌是砂金富集有利部位。该区金直接来源于加里东和华力西花岗岩。结合金的来源、矿床的分布特征和富集规律，指出了该区今后砂金找矿方向。  相似文献   

滇黔桂地区卡林型金矿床成因探讨   总被引：19，自引：2，他引：19  

贾大成  胡瑞忠 《矿床地质》2001,20(4):378-384

矿化剂和沉淀富集剂是成矿物质中的重要组成部分，也是人们分析成矿作用和建立成矿模式的基础。在分析滇黔桂地区金矿地质特征和成矿流体的基础上，提出该类矿床的矿质主要来源于被动陆缘沉积建造，促使金活化、迁移的矿化剂主要是盆地热卤素流体和有机质流体，促使金局部沉淀富集的沉淀富集剂则主要是沉积建造内和深源富硫的流体和热液改造的有机质。认为矿质、矿化剂和沉淀富集剂在有利容矿空间的耦合是形成滇黔桂地区卡林型金矿的主要成矿机制，并在此基础上讨论了卡林型金矿的成因和成矿模式。  相似文献   

Characterization of Geochemical Distributions Using Multifractal Models   总被引：2，自引：0，他引：2  

Mário A. Gonçalves 《Mathematical Geology》2001,33(1):41-61

The use of multifractals in the applied sciences has proven useful in the characterization and modeling of complex phenomena. Multifractal theory has also been recently applied to the study and characterization of geochemical distributions, and its relation to spatial statistics clearly stated. The present paper proposes a two-dimensional multifractal model based on a trinomial multiplicative cascade as a proxy to some geochemical distribution. The equations for the generalized dimensions, mass exponent, coarse Lipschitz–Hölder exponent, and multifractal spectrum are derived. This model was tested with an example data set used for geochemical exploration of gold deposits in Northwest Portugal. The element used was arsenic because a large number of sample assays were below detection limit for gold. Arsenic, however, has a positive correlation with gold, and the two generations of arsenopyrite identified in the gold quartz veins are consistent with different mineralizing events, which gave rise to different gold grades. Performing the multifractal analysis has shown problems arising in the subdivision of the area with boxes of constant side length and in the uncertainty the edge effects produce in the experimental estimation of the mass exponent. However, it was possible to closely fit a multifractal spectrum to the data with enrichment factors in the range 2.4–2.6 and constant K₁ = 1.3. Such parameters may give some information on the magnitude of the concentration efficiency and heterogeneity of the distribution of arsenic in the mineralized structures. In a simple test with estimated points using ordinary lognormal kriging, the fitted multifractal model showed the magnitude of smoothing in estimated data. Therefore, it is concluded that multifractal models may be useful in the stochastic simulation of geochemical distributions.  相似文献