Geological, geochemical characteristics and isotope systematics of the Longqiao iron deposit in the Lu-Zong volcano-sedimentary basin, Middle-Lower Yangtze (Changjiang) River Valley, Eastern China   总被引：8，自引：0，他引：8  

Zhou Taofa  Wu Mingan  Fan Yu  Duan Chao  Yuan Feng  Zhang Lejun  Liu Jun  Qian Bing  Franco Pirajno  David R. Cooke 《Ore Geology Reviews》2011,43(1):154-169

The Middle-Lower Yangtze (Changjiang) River Valley metallogenic belt is located on the northern margin of the Yangtze Craton of eastern China. Most polymetallic deposits in the Changjiang metallogenic belt are clustered in seven districts where magmatism of Mesozoic age (Yanshanian tectono-thermal event) is particularly extensive. From west to east these districts are: E-dong, Jiu-Rui, Anqing-Guichi, Lu-Zong, Tong-Ling, Ning-Wu and Ning-Zhen. World-class iron ore deposits occur in the Lu-Zong and Ning-Wu ore clusters, which are mainly located in continental fault-bound volcanic-sedimentary basins. One of these deposits is the Longqiao iron deposit, discovered in the northern part of the Lu-Zong Basin in 1985. This deposit consists of a single stratabound and stratiform orebody, hosted in sedimentary carbonate rocks of the Triassic Dongma'anshan Formation. A syenite pluton (Longqiao intrusion) is situated below the deposit. The iron ore is massive and disseminated and the ore minerals are mainly magnetite and minor pyrite. Wall rock alteration mostly consists of skarn minerals, such as diopside, garnet, potassic feldspar, quartz, chlorite, phlogopite and anhydrite. Thin sedimentary siderite beds of Triassic age occur as relict laminated ore at the top and the margin of the magnetite orebody. These sideritic laminae are part of Triassic evaporite-bearing carbonate deposits (Dongma'anshan Formation).Sulfur isotopic compositions show that the sulfur in the deposit was derived from a mixture of magmatic hydrothermal fluids and carbonate–evaporite host rocks. Similarly, the C and O isotopic compositions of limestones from the Dongma'anshan Formation indicate that these rocks interacted with magmatic hydrothermal fluids. The O isotopic compositions of the syenitic rocks and minerals from the deposit show that the hydrothermal magnetite and skarn minerals were formed from magmatic fluids. The Pb isotopic compositions of sulfides are similar to those of the Longqiao syenite. Phlogopite coexisting with magnetite in the magnetite ores yielded a plateau age of 130.5 ± 1.1 Ma (2σ), whereas the LA-ICP MS age of the syenite intrusion is 131.1 ± 1.5 Ma, which is slightly older than the age of phlogopite.The Longqiao syenite intrusion may have crystallized from a parental alkaline magma, generated by partial melting of lithospheric mantle, during extensional tectonics. The ore fluids were probably first derived from magma at depth, later emplaced in the sedimentary rocks of the Dongma'anshan Formation, where it interacted with siderite and evaporite-bearing carbonate strata, resulting in the formation of magnetite and skarn minerals. The Longqiao iron deposit is a skarn-type stratabound and stratiform mineral system, genetically and temporally related to the Longqiao syenite intrusion. The Longqiao syenite is part of the widespread Mesozoic intracontinental magmatism (Yanshanian event) in eastern China, which has been linked to lithospheric delamination and asthenospheric upwelling.  相似文献   

纳米铁还原脱氮动力学及其影响因素   总被引：3，自引：1，他引：2  

黄园英  秦臻  刘丹丹  王晓春 《岩矿测试》2011,30(1):53-58

饮用水中硝酸盐(NO3-)对人体健康有危害。为了去除水溶液中NO3-,在实验室制得纳米铁颗粒。它的粒径为20～40 nm,比表面积(BET)为49.16 m2/g。本研究通过批实验考察了纳米铁对NO3-还原脱氮动力学性质和影响NO3-脱氮快慢的主要因素,如反应pH、纳米铁投加量和NO3-起始浓度。实验结果表明,pH越低越有利于NO 3-还原。在一定范围内,NO 3-还原速率随纳米铁投加量增加而增大,而随NO 3-起始浓度升高而降低,反应遵循准一级反应动力学方程,表面吸附和氧化还原反应是纳米铁对NO3-脱氮的主要去除机理。纳米铁对NO3-还原过程中可能反应的途径进行了讨论,NO3-还原产物取决于反应条件。在本研究条件下,纳米铁对NO3-脱氮的最终产物主要为NH4+-N而不是N2,必须进行更多的研究来解决这一问题。  相似文献   

水浴消解-顺序注射-氢化物发生原子荧光光谱法测定铁矿石中砷和汞   总被引：2，自引：2，他引：0  

苏明跃  陈广志  王晶  姚传刚 《岩矿测试》2011,30(2):210-213

采用水浴加热低温消解浸取铁矿石样品,顺序注射-氢化物发生原子荧光光谱法测定铁矿石样品中砷和汞的含量.选择了消解试剂,研究了硼氢化钾浓度、载气流量、屏蔽气流量、溶液酸介质、载流、溶液酸碱比例、样品中的主要基体元素等因素对砷和汞测定的干扰,并确立了适宜的测定条件.砷浓度在0～100 μg/L与荧光强度呈良好的线性关系,砷的...  相似文献   

江西新余铁矿田铁矿成矿地质特征与成因分析   总被引：3，自引：0，他引：3  

曾书明 《地质与勘探》2011,47(2):187-196

本文总结了新余铁矿田矿层和含铁岩系变化特征、矿层顶板、底板和含铁岩系标志层特征以及矿田东、中、西段构造特征,分析了铁矿的沉积成岩作用以及构造演化历史,解释了新余铁矿田的各种成矿地质特征,并运用系统分析方法和历史分析方法说明矿田成矿地质系统的内在规律,认为该矿床属于火山-沉积变质铁矿,其物质成分较稳定,体现出规律性的变形...  相似文献   

ArcGIS在东昆仑西段铁矿资源预测中的应用——以矽卡岩型铁矿为例   总被引：1，自引：0，他引：1  

刘艳宾 《地质与勘探》2011,47(6):943-956

GIS在矿产预测中的应用研究日益普及和深化,在矿产勘查领域中已成为一种快速有效成矿预测方法。本文以东昆仑西段矽卡岩型铁矿为例,从研究区的地质背景和已查明的13个矽卡岩型铁矿（点）出发,基于ArcGIS平台,建立本研究区的空间数据库,结合已知矿（点）地质资料和野外验证分析,建立找矿模型与预测区提取模型,由于矽卡岩型矿床主...  相似文献   

新疆磁海铁矿床中黑柱石的发现及其地质意义     

唐萍芝  王玉往  王京彬  龙灵利  张会琼  廖震 《矿物学报》2011,31(1):9-16

黑柱石是一种不常见的夕卡岩标型矿物,本次研究在新疆磁海矿区首次发现黑柱石。本文对磁海矿区的黑柱石产出地质环境、矿物共生组合、化学成分、光学性质等进行了研究。化学成分均由电子探针分析求得,计算化学简式为Ca0.98(Fe1.72Mn0.07Mg0.11)1.902+(Fe0.95Al0.03)0.983+[Si2.00O7]O(OH)。磁海矿区黑柱石的形成与基性次火山热液活动有关,是一种特殊的退变质(蚀变)夕卡岩矿物;在成矿作用晚期,随着热液活动加强,早期夕卡岩矿物可退变质形成黑柱石。黑柱石形成时间较晚,对早期形成的磁铁矿起贫化作用。将磁海矿区黑柱石与国内外其它矿区黑柱石的化学成分进行了对比,认为磁海矿区黑柱石为普通黑柱石。黑柱石在常用的矿物中较少提及,应该引起重视。  相似文献   

孙家庄铁矿初级定向钻进及防斜措施   总被引：4，自引：2，他引：2       下载免费PDF全文

张文庆 《探矿工程》2011,38(12):22-24

介绍了山西省原平市孙家庄铁矿矿区的地层概况和矿体特征,收集汇总了该矿区的前期钻孔数据资料和存在的孔斜问题,对该矿区的钻孔孔斜情况及原因进行了分析,总结了该矿区的钻孔孔斜变化规律及特点,对钻探施工中的钻孔结构、钻具级配、套管选用、初级定向钻进方法及防斜措施进行了详细的介绍,并用钻探施工效果证明了采用的初级定向钻进方法和采取的防斜措施是可行和合理的。  相似文献   

Geochemical characterization of Archaean amphibolites from the eastern part of Anshan–Benxi iron producing area,northeastern China: implication for tectonic setting of BIFs     

En‐De Wang  Chang‐Ik Han  Jian‐Ming Xia  Jian‐Fei Fu  Guang‐Su Li  San‐Shi Jia  Ye‐Kai Men 《Geological Journal》2016,51(3):480-498

The Anshan–Benxi iron producing area, which is located at the northeastern margin of the North China Craton, is the main distribution area of Archaean BIFs in China. In their eastern part, including the Gongchangling and Waitoushan deposits, BIFs mainly are hosted in the Archaean middle Anshan Group. Amphibolites are widely distributed in the iron‐bearing rock series, reflecting the tectonic setting of BIFs. Amphibolites not only have MORB‐like compositional characteristics, but also have island arc‐like ones, and they are consistent with back‐arc basin basalts (BABB). In the study area, the protolith of amphibolites belongs to Okinawa‐type BABB; it indicates that tectonic setting of BIFs is the intra‐continental back‐arc basin. In the study area, the formation of sedimentary basins for BIFs had been associated with oceanic plate subduction. Amphibolites from Gongchangling deposit are characterized by relative enrichments in LILE and LREE, and depletions in HFSE. This indicates that they had a relatively large influence of subduction in their formation. Amphibolites from Waitoushan deposit are characterized by relative enrichments in LILE without conspicuous depletions in HFSE, indicating relatively low subduction rates. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

新疆富铁矿成矿特征及主攻类型成矿模式探讨   总被引：11，自引：0，他引：11  

董连慧  冯京  庄道泽  李凤鸣  屈迅  刘德权  唐延龄 《新疆地质》2011,29(4):416-422

富铁矿资源是我国紧缺战略资源,远远不能满足我国钢铁生产需求.近年来新疆富铁矿找矿重大突破表明,富铁矿是新疆优势资源,是我国寻找富铁矿重点远景区.从新疆实际地质条件和成矿特征出发,初步形成植根于新疆实际的“新疆富铁矿成矿新理论及主攻类型的成矿模式”,并分别构建了“上叠裂谷火山岩型富铁矿成矿模式”、“沉积变质-热液加富型铁矿床成矿模式”和“海相沉积-加富型菱铁矿矿床成矿模式”.这些成矿新认识和新成矿模式在本区铁矿评价中广泛应用,取得很好效果,丰富了铁矿成矿理论,拓展了新疆铁矿找矿领域.  相似文献   

高精度航磁调查在新疆西天山地区的应用   总被引：2，自引：1，他引：1  

郑广如  张玄杰  范子良  周坚鑫  宋燕兵  温世新 《物探与化探》2011,35(2):188-191

介绍了高精度航磁调查在西天山地区的应用效果,在高精度航磁图上,磁异常信息极为丰富,不仅已知铁矿在图上反映明显,而且还新发现了50余处铁矿异常,在已经进行了查证的5处异常中,有4处见矿,分别为14号、20号、169号和374号。这4处异常的成功发现不仅带来了巨大的经济效益,也为今后利用高精度航磁调查进行找矿提供了典型的实例。根据该区高精度航磁调查实际效果,笔者认为在新疆西天山地区,乃至整个中国西部勘查程度较低的地区,进行高精度航磁测量,并进行快速的地面查证工作,是寻找铁磁性矿产行之有效的方法。  相似文献