有机烃在预测隐伏金矿床中的应用及其成因探索   总被引：3，自引：0，他引：3  

徐庆鸿  陈远荣  毛景文  李晓峰  李厚民 《地质论评》2005,51(5):583-590

在国内外许多热液矿床的成矿作用研究中都发现有烃类组分的存在,这一现象已越来越受到矿床学家的关注。有机质、有机烃与金属成矿作用之间存在着直接或者间接的成因关系。有机烃指标应用于金属矿产勘查和深部隐伏矿体的预测是一个尚处于试验阶段的新的研究领域,其基础理论还不十分成熟。本文从有机烃预测隐伏金矿床的应用实例着手,归纳出金矿体上有机烃异常特征和模式,并对异常来源以及异常模式成因进行探讨,结果表明有机烃异常特征和有机烃组分间相关特性能有效反映深部隐伏金矿体的赋存空间和成矿规模,为利用有机烃预测隐伏金矿寻求更坚实的理论基础。  相似文献   

锍镍试金富集—等离子质谱法测定地质样品中的金铂钯铑铱钌   总被引：1，自引：0，他引：1  

施意华  靳晓珠  熊传信  黄俭惠 《矿产与地质》2009,23(1)

建立了锍镍试金富集—电感耦合等离子质谱法测定地质样品中金铂钯铑铱钌的方法。研究了富集时各种实验因素的影响,样品用琉试金富集,盐酸处理锍镍扣,碲共沉淀富集,过滤,沉淀用王水溶解,ICP-M S测定。方法检出限:A u为0.11、P t为0.050、Pd为0.028、R h为0.018、Ir为0.013、R u为0.02,相对标准偏差(n=12),A u为8.25%、P t为4.76%、P t为4.97%、R h为5.63%、Ir为5.38%、R u为6.81%。经国家一级地球化学标准物质验证,铂族元素和金的测定值与标准质相吻合。  相似文献   

越城岭-猫儿山地区花岗岩特征及成矿   总被引：2，自引：1，他引：1  

冯国玉  黄杰  何方 《矿产与地质》2009,23(5):412-417

越城岭-猫儿山地区花岗岩类岩石出露很广,侵入时代从加里东期至燕山期,为一套富硅、铝过饱和、燕山早期花岗岩体略富碱、分异演化程度较高的中粒-细粒黑云母花岗岩、二云母花岗岩和白云母花岗岩。岩石具有明显的富K2O,贫Na2O特征,为富含W、Sn、Pb和Bi的岩体,具备了为钨锡多金属矿化提供成矿物质和成矿热流体的内在条件。区内钨锡钼矿化与燕山早期花岗关系密切,矿床（点）产于细粒花岗岩周边、细粒花岗岩体与围岩接触带附近。  相似文献   

Early cretaceous subduction-related adakite-like rocks of the Gangdese Belt,southern Tibet: Products of slab melting and subsequent melt–peridotite interaction?     

Di-Cheng Zhu  Zhi-Dan Zhao  Gui-Tang Pan  Hao-Yang Lee  Zhi-Qiang Kang  Zhong-Li Liao  Li-Quan Wang  Guang-Ming Li  Guo-Chen Dong  Bo Liu 《Journal of Asian Earth Sciences》2009,34(3):298-309

The limited geochronology and geochemistry data available for the Early Cretaceous igneous rocks of the southern Gangdese Belt, southern Tibet, has resulted in the proposal of conflicting geodynamic models for the generation of the widespread Cretaceous igneous rocks in the middle and northern parts of the belt. To explore this issue, we present SHRIMP U–Pb zircon data and geochemical and Sr–Nd–Pb–Hf isotopic data for the Mamen andesites from the southern margin of the Gangdese Belt. The Mamen andesites, emplaced at 136.5 Ma, are sodic (Na₂O/K₂O = 1.2–2.3) and have geochemical characteristics typical of adakites (i.e., high Al₂O₃, high La/Yb ratios and Sr contents, low Y and HREE contents, and positive Eu anomalies), except for high Cr, Ni, and MgO contents. The andesites have initial (⁸⁷Sr/⁸⁶Sr)_t ratios of 0.70413–0.70513, positive εNd(t) values of 3.7–5.8, and (²⁰⁶Pb/²⁰⁴Pb)_t ratios of 18.37–18.51, (²⁰⁷Pb/²⁰⁴Pb)_t ratios of 15.59–15.65, and (²⁰⁸Pb/²⁰⁴Pb)_t ratios of 38.43–38.72. In situ Hf isotopic analyses of zircons that had previously been dated by SHRIMP yielded positive initial εHf(t) values ranging from +11.0 to +15.5. A model calculation using trace element and Sr–Nd–Pb isotopic data indicates that several percent of subducted sediment is required to generate the Mamen andesites, which were derived via the partial melting of subducted Neo-Tethyan slab (MORB + sediment + fluid) and subsequently hybridized by peridotite in the mantle wedge. Our data indicate that the Neo-Tethyan oceanic crust was subducted northward beneath the Gangdese Belt during the Early Cretaceous at a high angle. Our results are inconsistent with a tectonic model that advocates the low-angle or flat-slab subduction of Neo-Tethyan oceanic crust in generating the widespread Cretaceous magmatism recorded in the Gangdese Belt.  相似文献   

滇东罗平县雄武镇地区遥感蚀变信息提取及成矿预测   总被引：1，自引：0，他引：1  

张佩民  张建国  唐淑梅  杨自安  肖文进  郑跃鹏 《地质通报》2009,28(6):769-775

以含铁矿物和含羟基矿物在ETM数据的可见光-短波红外波段所具有的特征光谱为依据,在滇东雄武镇地区采用主成分分析的方法,选择适宜的主分量图像,对其进行均值滤波、密度分割等处理,获得了高值级、中值级和低值级3种级别的铁化和泥化蚀变异常信息。结合成矿地层、成矿构造、地球化学异常、重砂异常等多元信息,进行遥感成矿预测,提出铜钼汞和铜钼Ⅰ级成矿预测区各1个、铜锌Ⅱ级成矿预测区1个、锌砷锑和铁铜Ⅲ级成矿预测区各1个,从而为该区进一步开展普查找矿指出了方向。  相似文献   

昆明盆地地热钻井粘钻事故的分析与处理          下载免费PDF全文

林金福  李锡  罗文来 《探矿工程》2009,36(4):20-22

通过对昆明盆地地热井钻井施工中多口井发生粘钻事故原因的全面分析,研究出了一套应对该类事故的处理方法,从而有效地破解了该地区地热钻井施工中的技术难题。  相似文献   

Ostwald ripening as a possible mechanism for zircon overgrowth formation during anatexis: theoretical constraints,a numerical model,and its application to pelitic migmatites of the Tickalara Metamorphics,northwestern Australia     

《Geochimica et cosmochimica acta》2001,65(16):2771-2788

A fundamental dichotomy exists between the low solubility of zircon in peraluminous melt predicted by experimental and geochemical studies and the large volume proportions of zircon overgrowths formed during high-temperature metamorphism and anatexis that are revealed by cathodoluminescence imaging. We investigate the potential of Ostwald ripening as a possible mechanism for overgrowth formation by presenting a numerical solution to the continuity equation governing open system, diffusion rate-limited Ostwald ripening in a zircon-saturated melt. Application of the model to a typical (log-normal) initial zircon crystal size distribution (CSD) suggests that despite uncertainties associated with the interfacial free energy of zircon, significant grain coarsening is possible via this mechanism under geological conditions and time scales relevant to high-grade metamorphism. Primary influences on the rate at which Ostwald ripening proceeds are (i) the temperature of the system, (ii) the duration of the time interval for which the system is above its solidus, and (iii) the nature of the initial (premelting) zircon CSD.To test the viability of the model, we examine zircon CSDs from three high-grade pelitic migmatites of the Tickalara Metamorphics (northwestern Australia), assuming that zircon crystals hosted by melanosome biotite were permanently occluded from the melt (and therefore approximate the premelting CSD). The model predicts that within 1 to 2 Ma, these biotite-hosted zircon CSDs will evolve into the observed leucosome-hosted zircon CSDs via melt-present Ostwald ripening, under geological conditions applicable to peak metamorphism.Although we have not conclusively demonstrated that Ostwald ripening contributed to changes in zircon CSDs during anatexis of the Tickalara metapelites, our results suggest that Ostwald ripening is a viable mechanism for zircon volume transfer in a zircon-saturated melt and capable of playing a significant role in overgrowth formation in rocks where the total volume of zircon overgrowths substantially exceeds the concentration of zircon dissolvable in the coexisting melt.  相似文献   

广西泗顶—古丹铅锌矿田地质特征成矿规律及找矿标志   总被引：2，自引：0，他引：2       下载免费PDF全文

谢世业  黄有德  张国林  何国朝 《地质找矿论丛》2001,16(1):38-41

论述了泗顶－古丹铅锌矿田地质特征，总结成矿规律及找矿标志，指出古丹－泗顶SN向断裂为导矿断裂，NW，NNW向断裂与该断裂交汇区为铅锌矿床分布区。  相似文献   

烃、汞气体测量法常见干扰因素与消除     

陈远荣  郭世华  杨通树  张雪亮 《矿产与地质》2006,20(2):169-173

烃、汞综合气体测量法是金属矿床勘查中刚刚被人们重视的地球化学勘查新技术,在应用该新方法技术时,常常会遇到四大类干扰因素,即:断层、土壤性质(包括土壤类型、C aO含量、地表有机质、pH值)、地表特殊景观(包括地貌类型、污染河流)、地下非矿信息源(包括火成岩、煤系地层),文章阐述了这四大类因素引起的干扰异常的识别和其影响特征以及对这些干扰因素的消除办法。  相似文献   

广西河池市北香银-锌多金属矿床地质特征及成因探讨     

何国朝  秦来勇  伍静  张波 《矿产与地质》2006,20(6):608-611

北香是丹池成矿带上的一个重要构造隆起区,成矿条件良好,但是近四十年的地质勘查未能实现找矿的重大突破。通过对矿区成矿特征及控矿条件的分析,认为矿床明显受NW向同生沉积断层的控制,具有喷流沉积和后期热液叠加改造的两期成矿特征。目前发现的矿体仅是矿床上部脉状矿,其下部的下泥盆统中应存在层状似、层状的厚大矿体。  相似文献