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德兴铜厂斑岩铜(钼金)矿床蚀变-矿化系统流体演化:H-O同位素制约 总被引：2，自引：0，他引：2
江西铜厂斑岩铜(钼金)矿床是德兴斑岩矿集区最大的矿床.文章根据铜厂矿床发育的钾硅酸盐化、绢英岩化、青磐岩化蚀变组合特征,和已厘定的铜厂矿床脉体类型,选取代表不同蚀变矿化阶段的石英、黑云母、绢云母及绿泥石等,进行单矿物的H、O同位素测试.石英和黑云母单矿物O同位素,与石英、黑云母平衡流体的δ 18O 值和δD值联合示踪结果显示,铜厂矿床早期A脉(不规则疙瘩状A1脉、石英-黑云母A2脉和石英-磁铁矿A4脉)和中期B脉(矿物组合为石英-黄铁矿+黄铜矿±辉钼矿±斑铜矿)形成时,成矿热液均为岩浆流体来源,但B脉可能混入了少量大气降水;晚期低温D脉和碳酸岩脉(180～200℃)的成矿热液全部为大气降水来源.斑晶黑云母平衡水的δ 18O和δD值变化范围较大表明,黑云母形成时的热液系统主要为岩浆水,局部受区域变质水和大气降水的混染,也可能与少量黑云母斑晶受到后期绿泥石化、水云母化蚀变有关.绿泥石蚀变主要由岩浆流体作用形成,但混入了一些大气降水,导致其δ 18O值少量降低.绢云母平衡的水的δ18O值和δD值(4.6‰和-19.4‰)表明,绢云母是大气降水与千枚岩共同作用的结果.总体来说,铜厂矿床钾硅酸盐化、绿泥石化蚀变,以及钾硅酸盐化阶段形成的A脉和B脉,均由岩浆流体作用引起,大气降水在绿泥石化阶段进入蚀变-矿化系统,而绢云母化、晚期低温D脉和碳酸盐脉均是大气降水作用的产物. 相似文献
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碰撞造山型斑岩铜矿蚀变分带模式--以西藏冈底斯斑岩铜矿带为例 总被引：24，自引：0，他引：24
岛弧环境斑岩铜矿蚀变分带模式已为人们所熟知 ,但碰撞造山环境的斑岩铜矿蚀变分带特征尚不清楚。对此 ,文中以西藏冈底斯斑岩铜矿带为例 ,选择驱龙、冲江、厅宫 3个典型斑岩铜矿 ,对其蚀变系统进行了系统研究。依据蚀变矿物组合可分为 3个蚀变带 ,呈环带状分布。从中心向外依次为钾硅酸盐化带、石英绢云母化带、青磐岩化带。泥化带不太发育 ,通常叠加在其它蚀变带之上。钾硅酸盐化带主要蚀变矿物为钾长石、黑云母、石英、硬石膏 ,伴有大量的黄铜矿与辉钼矿 ,是成矿物质的主要堆积区。石英绢云母化带与钾硅酸盐化带渐变过渡或叠加其上 ,是次于钾硅酸盐化带的储矿部位。蚀变矿物组合为绢云母 +石英 +钾长石 ,金属硫化物有黄铁矿、黄铜矿、辉钼矿、斑铜矿 ,少量的方铅矿、闪锌矿。主要的辉钼矿以石英 +辉钼矿脉的形式出现于本矿带。青磐岩化在斑岩体内不发育 ,矿化极微弱。蚀变岩石组分分析表明 ,岩石蚀变及其分带是岩浆流体 /岩石反应时K ,Na ,Ca ,Mg等组分迁移的结果 ,矿化伴随着蚀变发生。钾硅酸盐化带、石英绢云母化带和青磐岩化带的蚀变岩石与未 (弱 )蚀变斑岩具有一致的稀土配分模式 ,REE含量有规律地变化 ,说明蚀变岩石均经历了源于岩浆的流体的交代 ,不同的蚀变形成于岩浆流体演化的不同阶段。蚀? 相似文献
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针对自然降尘进行的物相、成分分析表明该降尘的物相组成非常复杂,以石英、方解石、钠长石、白云石、云母为主要物相成分。为探讨降尘中矿物在有机酸中的溶解情况,进一步揭示其对人体的危害程度。本文以西宁降尘为研究对象,并选择柠檬酸为代表有机酸,分别用XRD、FTIR及ICP-AES等方法对柠檬酸处理前后降尘的残余固体及反应上清液进行分析。结果表明,降尘中方解石在经柠檬酸作用10 min后完全溶解,白云石在16 h内基本溶解完全,根据红外分析结果,Si—O、Al—O结构未发生明显破坏。然而,溶出元素结果显示,Al、Si的溶出量随着溶解时间的增长而缓慢增加,说明柠檬酸对Si—O四面体及Al—O八面体也造成了一定的破坏作用。通过分析降尘中3种难溶矿物在相同条件下的溶解速率可以得出,在整个溶解过程中,钠长石的溶解速率高于绢云母,而石英的溶解速率在不同的溶解时间有着较大的差异。根据3种纯矿的溶解速率推断三者的溶解顺序,钠长石明显先于云母溶解,石英的溶解先后顺序还有待进一步研究。通过降尘及纯矿在柠檬酸中溶解过程中不同时刻的元素溶出比例及矿物溶出速率可以得出除石英外4种主要矿物的溶解顺序为:方解石,白云石,钠长石,绢云母。 相似文献
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红外光谱技术,辅以显微镜下鉴定和矿物地球化学分析,通过系统采集达斯矿区地表岩石与钻孔岩芯样品,开展精细蚀变矿物填图,利用绢云母矿物Al- OH基团在2200 nm附近的光谱变化特征,开展勘查区及其外围的找矿预测。结果显示：① 研究区主要矿物为钠长石、微斜长石、石英、绢云母、高岭石、蒙脱石和绿泥石,另含有少量明矾石、电气石、石膏和黑云母等;② 电气石、明矾石、高岭石和绢云母矿物及其组合与成矿关系密切,具有中硫化浅成低温热液型矿床蚀变矿物组合特征;③ 目前已发现的Pb矿（化）体,主要产于300 m以浅,矿体底板为一套蒙脱石+绿泥石为主的蚀变矿物组合。矿体赋存于绢云母（高岭石+少量明矾石+电气石）蚀变带内,蚀变分带特征（矿化体中心向外）表现为：绢云母化→绢云母+高岭石（+少量明矾石+电气石）→绢云母+蒙脱石→蒙脱石+绿泥石;④ 区内长波绢云母指示了深部热源的位置,短波绢云母反映出热液流体与浅部大气降水的混合作用,根据绢云母矿物Al- OH波长插值填图及矿物组合特征变化确定了成矿流体pH值偏中性、温度逐渐降低的变化趋势;⑤ 绢云母矿物在2200 nm附近的光谱吸收深度与Pb品位之间呈正相关关系,10%吸收深度阈值可区分具有相似Al- OH吸收特征的绢云母和高岭石矿物;⑥ 结合GIS空间叠加分析,认为勘查区外围仍具一定找矿潜力。 相似文献
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本文详细地描述了沥青铀矿和辉钼矿组合的矿化特征。列举了沥青铀矿与辉钼矿、方铅矿、闪锌矿、绢云母、碳酸盐等的相互关系。从而说明:矿物自溶液中析出的时间相近、矿化与围岩蚀变关系紧密。同时,划分出两种蚀变类型:1)钠长石化和碳酸盐化岩石,2)绢云母化和矽化岩石。根据不同的围岩蚀变和矿物在矿带中的分布特点,进而划分三种矿带类型:第一类矿带、上部以棋盘状钠长石和碳酸盐蚀变为特征,沥青铀矿大量富集。下部为绢云母和石英,辉钼矿则占优势;第二类矿带下部,矽化、绢云母化特别强烈,沥青铀矿仅见于上部;第三类矿带上部,钠长石增多,富铀而贫钼,下部则相反。以上说明:铀的富集随着岩石钠长石化强度之增加而加强,钼只富集于绢云母化和矽化地段。最后,本文对围岩蚀变和成矿作用的地球化学过程,也作了简要的理论分析。 相似文献
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《地球化学》2016,(6)
红海VMS铜锌矿床位于新疆东天山大南湖-头苏泉岛弧带的卡拉塔格地区,矿床上部发育似层状块状硫化物矿体,下部为不整合的脉状-网脉状矿体,块状矿体上盘火山岩盖层中也发育少量铜矿化。本文在前人工作基础上,根据矿物交代次序、脉体穿插关系和矿物共生组合类型,精细划分了矿床的蚀变分带和成矿期次。矿床(含盖层)从浅到深依次发育绿泥石-钠长石-绢云母-碳酸盐化、绿帘石-绿泥石-钠长石-绢云母-碳酸盐化、石英-绢云母-黄铁矿化、块状硫化物矿体、绿泥石-黄铁矿±绢云母化和绿泥石-石英-绢云母化。红海矿床成矿过程可分为VMS成矿期、后期热液叠加期和表生期,其中VMS成矿期可细分为黄铁矿阶段、黄铜矿-闪锌矿阶段和重晶石阶段,后期热液叠加期可细分为钠长石化阶段、绿泥石-绿帘石阶段和石英-碳酸盐阶段。主矿化期及蚀变特征与典型VMS矿床类似,但同时还表现出许多海底交代作用的特征。后期热液在矿体上盘火山岩中所产生的绿帘石化、绿泥石化和绿帘石-石英-黄铜矿-斑铜矿脉、石英-碳酸盐脉等蚀变和矿化,与斑岩矿化系统的青磐岩化类似,表明红海矿床后期可能受到斑岩系统的叠加,矿区具有斑岩铜矿床的找矿潜力。 相似文献
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《矿物学报》2013,(Z1)
By detecting the influence of six main ingredients of PM2.5 mineral dusts on the A549 cell morphology, proliferation inhibition rate, micronuclei and DNA damage, to explore the genotoxicity of PM2.5 mineral dusts. (1) After exposure to six kinds of dusts of 200 μg/mL concentration for 24 hours, the morphology of A549 cells were observed using Wright-Giemsa staining. (2) After exposure to different concentrations of mineral dusts for 24 hours, the proliferation inhibition rate of A549 cells was detected by MTT assay. (3) Cells were exposed to PM2.5 mineral dusts at a concentration of 200 μg/mL for 24 h. After Wright-Giemsa staining, the rates of micronucleus cells were counted under oil microscope. (4) Observe Comet phenomenon by SCGE electrophoresis, the degree of DNA damage was observed by OTM. (1) Compared to the control group, membrane destruction, nuclear pyknosis and mineral surface adhesion were mainly seen in the Sericite group and Albite group. In the Quartz group and Montmorillonite group, enlarged cell gaps, loosely arranged cells, absorption of a large number of minerals on the cell surface, and cell pyknosis were observed. (2) The proliferation inhibition rate of the six kinds of dusts to A549 cells were (from large to small): KWC-M>Nano-SiO2>KWC-S>KWC-Q>KWC-A>KWC-C.The dust concentration was positively related to the inhibition of cell proliferation rate. (3) With the dusts concentration increased, the incidence of micronuclei gradually increased. The rate was positively correlated to exposure concentration. (4) The six mineral dusts can damage DNA of the A549 cells by dose-response relationship.The higher concentration of the mineral dusts, the more obvious of the DNA damagenation. There’s statistically significant compared with the control group. The six main ingredients of the PM2.5 mineral dusts can change A549 cell morphology from varying degrees, improve proliferation inhibition rate of the cells, increase the number of micronuclei cells, damage DNA.Then we come to the conclusion that PM2.5 mineral dusts can change the genotoxicity of the cells. 相似文献
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In order to compare the chemical compositions and physical properities of dusts on silicate bacteria S35, the chemical compositions of six kinds of mineral dusts have been analyzed and the changes of pH value, glucose （GLU）, electrolyte and Mn, Si, Fe before and after the dusts reacted with silicate bacteria S35 have been measured. The SEM analysis has been used to study the bacterial form and interface action status in the course of reaction between dusts and bacteria. The results show that these mineral dusts have different effects on experiment bacteria. Therefore, it is concluded that the effect of mineral dusts on silicate bacteria has correlation with the chemical compositions and physical properities of dusts. 相似文献
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大气粉尘中的矿物及其环境健康效应研究进展 总被引：3，自引：0，他引：3
大气粉尘中的矿物主要来源于土壤尘、建筑工地和局地扬尘,颗粒较小,一般呈不规则形状,表面凹凸不平。矿物粉尘具有很强的生物活性,对人体健康、生物效应有其特有的生理作用。矿物粉尘表面活性基团影响粉尘的生物效应。矿物粉尘本身或刺激吞噬细胞而产生的自由基对细胞的损伤和粉尘性疾病的形成起着至关重要的作用。大气粉尘成分、表面特性以及矿物粉尘对人体正常宿主菌群的抑制性和毒性效应研究是矿物粉尘环境健康效应研究的重要方向。 相似文献
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DONG Faqin DENG Jianjun WU Fengchun PU Xiaoyong John HUANG FENG Qiming HE Xiaochun 《《地质学报》英文版》2006,80(4):589-596
In order to study the damage mechanism of mineral dusts on the pulmonary alveolar macrophage （AM）, the changes in their death ratio, malandialdthyde （MDA） content and activities of lactate dehydrogenase （LDH） and superoxide dismutase （SOD） were measured, and the technique of cell culture in vitro was used to investigate the cytotoxicity of six mineral dusts （twelve crystal habits） from twelve mineral deposits. The results show that woUastonite and clinoptilolite have no AM cytotoxicity, while other fibrous and grainy mineral dusts damage pulmonary AM in various degrees. The cytotoxicity of fibrous mineral dusts was greater than that of the grainy ones, and the cytotoxicity of dusts was positively correlated with the active OH- content in dusts, but not necessarily so with its SiO2 content. The high pH values produced by dust was unfavorable for the survival of cells and the dusts with low bio-resistance were safe for cells. The content of variable valence elements in dusts might influence their cytotoxicity and the surface charge of dusts was not a stable factor for their toxicity. It is demonstrated that the shape of mineral dusts was one of the factors affecting cytotoxicity, and that the cytotoxicity of mineral dusts depends mainly on their properties. 相似文献
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陕西省铧厂沟金矿床位于勉略缝合带以南,矿体受控于近东西向逆冲断层和韧脆性剪切带。本文以细碧岩矿带为例,系统研究了围岩蚀变分带及蚀变矿物组合,总结了矿床的蚀变分带模式。围岩蚀变以穿切细碧岩透镜体的剪切带为中心向外依次可划分为黄铁绢英岩化带、绢云碳酸盐化带和绿泥赤铁矿化带。蚀变矿物组合分别为黄铁矿＋铁白云石＋铬云母＋绢云母＋钠长石＋石英＋方解石、铁白云石＋绢云母＋钠长石＋石英±黄铁矿、（铁）绿泥石＋钠长石＋铁白云石＋赤铁矿＋钛铁氧化物＋石英±绿帘石。蚀变岩石组分迁移分析表明,在围岩蚀变过程中, SiO2、Na2O、Fe2O3T、MgO与Y等组分发生不同程度的迁出, K2O、CaO、Ba、Rb、Sr、Cr、Cu、Pb和挥发组分等迁入,并以黄铁绢英岩化带最为显著。金在成矿流体中以Au（HS）–2络合物迁移,成矿流体与富铁细碧岩之间的反应是金沉淀重要机制。 相似文献
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A. J. Mauger K. Ehrig A. Kontonikas-Charos C. L. Ciobanu N. J. Cook V. S. Kamenetsky 《Australian Journal of Earth Sciences》2016,63(8):959-972
Twenty thousand metres of diamond drill core representing a 14 km cross-section from weakly to intensely altered Roxby Downs Granite through the Olympic Dam Breccia Complex, host to the Olympic Dam iron-oxide–copper–gold–uranium deposit in South Australia, was analysed using the HyLogger-3 spectral scanner. Thermal and shortwave infrared spectroscopy results from 30 drill holes provide insight into the spatial relationships between quartz, orthoclase–microcline, albite–oligoclase and progressively changing sericite and chlorite compositions. The relative proportions of quartz, feldspars and phyllosilicates were mapped with thermal infrared spectroscopy. Variations in the chemistry of sericite and chlorite were extracted by proxy from their shortwave infrared spectral response, together with their relative spatial distribution. HyLogger scanning has revealed four deposit-scale mineralogical trends, progressing from least-altered Roxby Downs Granite into mineralisation where most of the feldspar has been replaced by sericite + hematite + quartz: (1) a progressive Al–OH wavelength shift of 2205 nm to 2210 nm for sericite, followed by a spatially rapid reversal corresponding to lower phengite/muscovite abundance ratios; (2) progressive Mg/Fe–OH wavelength shift of 2248 nm to 2252 nm reflecting an increase in the Fe:Mg ratio of chlorite; (3) increasing ratio of microcline to orthoclase followed by a rapid decrease; and (4) slightly decreasing ratio of albite to oligoclase followed by plagioclase destruction prior to albite replacement by sericite. The HyLogger feldspar results support recent petrographic evidence for hydrothermal albite and K-feldspar at the Olympic Dam deposit, not previously reported. The spectral results from continuous HyLogger scans also show that the microscopic observations and proposed feldspar replacement reactions are not locally isolated phenomena, but are applicable at the deposit and regional-scale. A modified quartz–K-feldspar–plagioclase ternary diagram utilising mineralogy interpreted from HyLogger thermal infrared spectra (QAPTIR) diagram along with supporting data on the abundance ratios of orthoclase/microcline and albite/plagioclase, and the wavelength shifts in characteristic absorption features for sericite and chlorite, can be used as empirical vectors towards mineralisation within the Olympic Dam mineral system, with potential application to other IOCG ore-forming systems. Intrusion of Gairdner Dyke Swarm dolerite dykes into sericite ± hematite altered Roxby Downs Granite results in retrograde albite–chlorite–magnetite alteration envelopes (up to tens of metres thick) overprinting the original sericite ± hematite alteration zone and needs to be carefully evaluated to ensure that such areas are not falsely downgraded during exploration. 相似文献
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介绍了密度差值很小的单矿物的分离技术方法,并利用重液折光率千分位和万分位的细微区别分离单矿物石英和绢云母。该方法由石英与长英质混合物的分离技术,推广到绢云母与绢云母长英质混合物的分离技术,改进后的重液分离技术具有快速、高效、经济的特点。当重液的折光率为1.577～1.580时,石英的分离纯度能达到95﹪～99﹪;当重液的折光率为1.5895～1.5840时,绢云母的分离纯度能达到90﹪～99﹪。 相似文献