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1.
癞子岭岩体具有极好的垂向分带性,从下部到顶部包括了花岗岩、云英岩和伟晶岩,其中云英岩以其厚度巨大,云母类型属于铁锂云母,黄玉含量高,W-Sn-Nb-Ta含量高,而区别于其他地区云英岩。通过对癞子岭云英岩进行岩石学、地球化学和矿物学的研究,本文得出:癞子岭云英岩是高硅的强过铝质岩石类型,全碱含量低(3~4.3 wt%),富集挥发组分,全岩Zr/Hf(~8)和Nb/Ta(~1.7)比值低。造岩矿物铁锂云母中Nb(~74×10~(-6))、Ta(~66×10~(-6))、W(~23×10~(-6))、Sn(~75×10~(-6))等成矿元素含量较高。副矿物锆石自形且成分均一,含有HfO_2约10 wt%,Zr/Hf比值最低为5,与云英岩下部的癞子岭钠长花岗岩中的锆石成分有连续过渡的关系。这些特征与南岭地区高演化稀有金属花岗岩或伟晶岩相当,体现了相近的演化程度。癞子岭云英岩中有明显的Nb-Ta-W-Sn成矿作用发生,主要形成铌铁矿族矿物、锡石和黑钨矿,成分和结构均具有岩浆成因特征。花岗质熔体中含有大量挥发组分Li和F,结晶出黄玉和Li-F云母,F在稀有金属的成矿作用和云英岩的成岩过程中发挥了非常重要的作用,成矿作用发生在岩浆演化的晚期并伴随有流体作用。因此,云英岩可能是钠长花岗岩高度分异演化之后的特殊产物,这为研究花岗岩岩浆-热液体系成岩成矿过程提供了新的窗口。 相似文献
2.
华南花岗岩成因演化的云母稀土元素特征 总被引：2，自引：0，他引：2
华南两个系列花岗岩中黑云母的REE含量不同,南岭系列大于长江系列,但南岭系列白云母的REE含量最低。云母的REE标准化配分模式与全岩的相似,长江系列为Eu无明显异常的右倾斜形态,南岭系列为Eu明显负异常的V形态。随成岩演化,云母中REE与母岩REE同步演变,云母的REE特征可以作为花岗岩成因和REE自身成矿演化以及成矿专属性的示踪剂。长江系列主要在演化晚期阶段富集成矿,南岭系列主要在早期富集成矿。云母的REE特征主要受花岗岩物源化学背景的制约,同时也受岩浆分异演化程度和物理化学条件等的影响。 相似文献
3.
锡钨多金属矿化多与Li-F碱长花岗岩有关,其岩浆演化晚期常发生较大规模的液态分异作用。广西栗木锡钨铌钽矿与成矿有关的岩体包括肉红色中粒碱长花岗岩以及顶部的白色细粒碱长花岗岩。矿化产于碱长花岗岩顶部附近,主要矿化类型包括花岗岩型钨锡铌钽矿化、似伟晶岩型钨矿化、长石石英脉型钨矿化和石英脉型钨锡矿化。碱长花岗岩中存在大量岩浆液态不混溶现象,包括矿囊、似伟晶岩和细晶岩等。地质地球化学研究发现,岩浆液态不混溶作用贯穿于栗木碱长花岗岩分异演化的全过程,矿囊代表岩体中富含钨锡和挥发份的岩浆,岩体顶部的似伟晶岩和细晶岩是碱长花岗岩岩浆分异的结果。在岩浆液态不混溶作用过程中,W、Sn、Nb、Ta等成矿元素以及挥发份不断富集,形成岩浆岩型、长英质脉型以及石英脉型矿化。不同类型的矿化对应岩浆液态不混溶作用的不同阶段,由此建立了栗木矿床岩浆液态不混溶的成矿演化模型。 相似文献
4.
赣西北矿集区是中国重要的花岗岩型锂矿资源基地,以发育多期次多阶段岩浆作用和大规模锂等稀有金属矿床著称。区内花岗质岩浆与稀有金属成矿关系密切,为进一步研究该地区花岗质岩浆演化特征及其与稀有金属成矿的联系,确定相关花岗岩成岩时代及成因类型,查明稀有金属成矿机制,笔者选择九岭地区狮子岭花岗岩作为研究对象,对其开展了岩相学、锆石U-Pb年代学及岩石地球化学分析。结果显示,狮子岭花岗岩属高钾钙碱性系列,具有高Si,富P,贫Ca、Mg、Fe,富集U、Hf等高场强元素,亏损Ba、Sr等大离子亲石元素,稀土元素总量较低（ΣREE=2.12×10-6~146.24×10-6）,轻稀土元素相对富集（LREE/HREE=3.5~16.53）,弱Eu负异常（δEu=0.23~0.59）的特征。整体上具有S型花岗岩的地球化学特征。锆石U-Pb定年显示,黑云母二长花岗岩成岩年龄为（141.02±0.59）Ma,锂（白）云母碱长花岗岩成岩年龄为（113.96±0.72）Ma。锂（白）云母碱长花岗岩成岩过程中形成磷锂铝石及锂云母等含锂矿物,其成岩年龄可视为锂等稀有金属成矿年龄。该区稀有金属矿化受燕山晚期岩浆结晶分异作用及后期热液交代作用共同影响,岩浆结晶分异作用是Li、Nb、Ta成矿的决定性因素,后期热液交代作用为Li等成矿元素的二次富集提供条件。 相似文献
5.
本文根据南岭地区40个不同矿化类型的花岗岩体成矿金属元素的丰度、挥发组分的含量、岩体规模、侵位深度等的不同,将成矿花岗岩主要分为两类:铌钽(钨锡)成矿花岗岩和锡成矿花岗岩。并认为前者主要为射气分异作用成矿,后者为岩浆期后热液萃取富集成矿。两类成矿花岗岩具有不同的迁移、富集机制和控制因素。 相似文献
6.
石英脉型钨矿床中云英岩析离体及岩浆液态分异成矿研究——以湖南瑶岗仙钨矿床为例 总被引：11，自引：3，他引：8
云英岩析离体(包体)常见于南岭地区石英脉型(黑)钨矿床的成矿花岗岩体顶部附近,这些析离体多呈不规则椭球状,与寄主岩石花岗岩围岩界线明显,无与外面连通的脉体或构造,分布无规律。在湖南瑶岗仙钨矿床,云英岩析离体赋存于瑶岗仙岩体主体的灰色斑状碱长花岗岩Ⅰ中,大部分有分带,外带为云英岩化碱长花岗岩,富含辉钼矿,最高达5%以上,钠长石An平均为0.64;内核部分为云英岩,主要矿物组合为白云母、石英、萤石、黄玉、黑钨矿等,与黑钨矿石英脉相同,其黑钨矿含量最高达20%以上,属热液沉淀形成。云英岩析离体整体呈现出浆液过渡态流体作用的特征,是富Li-F碱长花岗岩浆液态分异作用的产物。与碱长花岗岩围岩相比,析离体中富集金属元素W、Mo、Bi及Li、Rb等元素,相对贫Co、Ni、Sr、Ba等元素,Cu、Pb、Zn的含量变化不明显。这种元素富集规律与区域岩浆演化趋势基本一致,显示岩浆晚期液态分异形成浆液过渡态流体是W等成矿元素富集的重要机制,但这一机制并不会导致Pb、Zn的富集,这一点不同于矽卡岩型钨矿床。石英脉型(黑)钨矿床的成矿地质体是灰色斑状碱长花岗岩Ⅰ,云英岩析离体是该岩体岩浆液态分异的结果,可以作为识别碱长花岗岩含矿性的重要标志(寻找石英脉型钨矿矿床)。 相似文献
7.
南岭地区钨锡花岗岩的成矿矿物学：概念与实例 总被引：7，自引：0，他引：7
南岭地区的钨锡成矿作用与花岗岩岩浆活动有十分密切的关系。花岗岩的物源与成矿元素的初始富集、花岗岩的分异程度和花岗岩中流体性质与活动性集中体现了花岗岩对成矿的控制能力,即花岗岩的成矿能力。初步建立了南岭地区钨锡花岗岩的成矿矿物学研究体系。黑云母、榍石、锆石、锡石、金红石、黑钨矿、白钨矿和钨铁铌矿等是讨论的重点矿物,它们可用于判别花岗岩的成矿能力。首先以矿物晶体化学为基础,介绍了上述矿物在钨锡花岗岩中的岩相学特征、内部构造和矿物化学及其变化,并分别论证了花岗岩原始含矿性、花岗岩结晶演化和花岗岩中成矿元素活动性的矿物学标志;其次,系统对比了南岭地区三类钨锡花岗岩（准铝质含锡花岗岩、过铝质含锡花岗岩和过铝质含钨花岗岩）的成矿矿物学特征。以湖南骑田岭花岗岩复式岩体为实例,进行了芙蓉- 菜岭含锡花岗岩和新田岭含钨花岗岩的成矿矿物学对比研究。前者以黑云母、榍石为典型含锡矿物,它们在流体富集阶段,经热液蚀变作用,导致锡的淋滤和结晶富集作用;后者则以出现岩浆白钨矿和黑钨矿为特征。提出的钨锡花岗岩成矿矿物学研究体系有助于深化矿床学研究和矿床勘探工作,并将在今后工作中进一步完善。 相似文献
8.
石英脉型钨矿床是南岭钨矿成矿带的主要矿床类型,含钨石英脉产于成矿花岗岩顶部的接触带附近,其中"带外脉式"的石英脉几乎全部产于接触带外侧。湖南白云仙钨矿田头天门钨矿床发育较完整的"带外脉式"钨矿矿化组合和空间分带,主要矿化类型包括花岗岩型和石英脉型,前者分布于岩墙上部,后者发育于上方外侧的砂岩中。笔者研究了头天门钨矿床中花岗岩和各类矿体的地质地球化学特征,探讨了岩浆演化与钨的富集成矿过程。提出头天门钨矿床粗粒斑状黑云母花岗岩→细粒碱长花岗岩岩株→岩墙→云英岩化花岗岩→云英岩→石英脉的岩浆-热液演化-成矿全过程,成矿流体表现出"上液下浆"的分带特点。在岩墙形成前的演化过程中,成矿元素的富集主要受岩浆晚期分异作用的制约,岩墙之后的演化则主要受热液作用的影响。成矿地质体为细粒碱长花岗岩岩株以及上部的岩墙。建立了带外脉式型钨矿床成矿模型,形成机制主要为:在岩浆固结之前,岩浆中的挥发分和H2O在岩体顶部聚集引起围岩破裂,岩浆充填形成岩墙,挥发分和成矿物质在岩墙上部聚集形成花岗岩型(云英岩型)钨矿,并在外侧形成石英脉型钨矿。 相似文献
9.
从云母微量元素特征探讨华南花岗岩的成因和演化 总被引：5，自引：1，他引：5
云母中微量元素可分为浅源指示元素和深源指示元素。浅源指示元素Nb、Ta、Sn、Li、Rb在南岭系列云母中的含量高于长江系列,而深源指示元素Co、Ni的含量长江系列大于南岭系列。云母中Nb、Ta、Sn、Li、Rb变化特征是自身成矿演化的直接示踪剂,而Co、Ni变化特征是Fe、Cu、Au、Mo(W)、Pb、Zn成矿演化的重要示踪剂。云母中Cu、Zn、W、Mo、U、Th等元素呈波动性变化,不能灵敏指示花岗岩的成因与演化。微量元素在云母中的选择分布主要受岩浆物源化学背景的制约,同时也受岩浆侵位和分异演化程度高低以及结晶的物理化学条件变化等因素的影响。 相似文献
10.
江西雅山花岗岩岩浆演化及其Ta-Nb富集机制 总被引：7，自引：7，他引：0
雅山岩体是华南地区著名的富含钽铌矿的稀有金属花岗岩。从早阶段到晚阶段花岗岩中的云母的Li、F和Rb2O含量逐渐升高,其类型变化为“黑鳞云母→Li-云母→锂云母”。锆石的Zr元素被Hf、U、Th、Y和P等元素的置换比例随着岩浆演化程度升高而增大。云母和锆石矿物成分变化特征与全岩体系的Zr/Hf、Nb/Ta比值不断下降而F、Li和P2O5含量逐渐升高的趋势一致,将可以用于指示岩浆演化程度。在岩浆演化过程中不断富集的P、F、Li元素增加了熔体中非桥氧数（NBO）,促使钽-铌元素在岩浆中的溶解度加大而逐渐富集,在最晚阶段的黄玉锂云母花岗岩具有最高的Ta、Nb元素含量。因此,雅山花岗岩具有较高的F、Li、P2O5含量是其岩浆演化及其Ta-Nb富集的重要机制。西华山花岗岩中的云母与雅山花岗岩中的锂云母相比,具有明显较低的F、Li、Rb2O含量,表明西华山花岗岩的岩浆演化程度相对低于雅山花岗岩。西华山花岗岩中的钨富集与流体作用密切相关,体系氧逸度的降低促使了钨成矿。因此,岩浆演化程度的不同可能是造成华南稀有金属花岗岩发生不同成矿作用（如Ta-Nb矿和W矿）的重要原因。 相似文献
11.
S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
12.
13.
奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
14.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
15.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
16.
17.
岩石密度和超高压岩石折返速率 总被引：1，自引：3，他引：1
在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。 相似文献
18.
Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA 总被引：1，自引：0，他引：1
The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. 相似文献
19.
滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床. 相似文献
20.
Alexander E. C. Broberg J. S. Kehren A. R. Graziani M. M. Turri W. L. 《Environmental Geology》1993,22(4):353-361
Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×106 1 of partially treated effluent and about 600 m3 of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes. 相似文献