高精度磁测在某钨锡矿区的应用   总被引：1，自引：0，他引：1  

黄理善  敬荣中  曾晖  曾高福  王建超 《矿产与地质》2009,23(3):277-281

野外岩、矿石物性测定表明,研究区内钨锡石英脉矿石磁化强度大于5000×10-3A.m-1,而正常围岩和热变质弱蚀变岩石为微磁性或弱磁性,这为在矿区进行高精度磁测提供了可靠的地球物理依据。本次工作在研究区内进行了地面高精度磁法测量,探测地下钨锡矿化岩体引起的磁异常,并结合地质和钻探资料,对地下矿体进行磁异常人机交互反演,取得了较好的效果。  相似文献   

新疆阿吾拉勒西段穷布拉克铜矿地质特征及控矿条件分析   总被引：1，自引：0，他引：1  

杨明德  莫江平  蔡宏渊 《矿产与地质》2009,23(3):230-234

新疆穷布拉克铜矿位于西天山阿吾拉勒山西段,矿床产于古生界二叠系之上、下二叠统不整合界面之内外侧的火山熔岩及沉积火山凝灰质砂砾岩中,具明显层控特征,矿体呈似层状、透镜状顺层产出,产状与地层基本一致。矿化富集与断裂及火山-次火山热液活动有关,主要矿体受近EW向穷布拉克断裂及其派生的次级裂隙带控制,矿床围岩蚀变较强烈,主要为绿泥石化、碳酸盐化。  相似文献   

广西栗木锡矿区深孔钻进工艺研究   总被引：3，自引：0，他引：3  

李平 《矿产与地质》2009,23(4):384-387

通过对栗木锡矿复杂地层的分析,采用绳索取芯技术,多级套管根管技术,优质泥浆护壁堵漏等钻进工艺,并对孔内事故的预防与处理提出了一系列措施,成功解决了该区深孔钻进的难题,取得了很好效果。  相似文献   

Post-collisional potassic magmatism in the eastern Lhasa terrane,South Tibet: Products of partial melting of mélanges in a continental subduction channel     

《Gondwana Research》2017

Post-collisional, potassic magmatic rocks widely distributed in the eastern Lhasa terrane provide significant information for comprehensive understanding of geodynamic processes of northward subduction of the Indian lithosphere and uplift of the Tibetan Plateau. A combined dataset of whole-rock major and trace elements, Sr–Nd–Pb isotopes, and in situ zircon U–Pb dating and Hf–O isotopic analyses are presented for the Yangying potassic volcanic rocks (YPVR) in the eastern part of the Lhasa terrane, South Tibet. These volcanic rocks consist of trachytes, which are characterized by high K₂O (5.46–9.30 wt.%), SiO₂ (61.34–68.62 wt.%) and Al₂O₃ (15.06–17.36 wt.%), and relatively low MgO (0.47–2.80 wt.%) and FeO_t (1.70–4.90 wt.%). Chondrite-normalized rare earth elements (REE) patterns display clearly negative Eu anomalies. Primitive mantle-normalized incompatible trace elements diagrams exhibit strong enrichment in large ion lithophile elements (LILE) relative to high field strength elements (HFSE) and display significantly negative Nb–Ta–Ti anomalies. Initial isotopic compositions indicate relatively radiogenic Sr [(⁸⁷Sr/⁸⁶Sr)_i = 0.711978–0.712090)] and unradiogenic Nd [(¹⁴³Nd/¹⁴⁴Nd)_i = 0.512121–0.512148]. Combined with their Pb isotopic compositions [(²⁰⁶Pb/²⁰⁴Pb)_i = 18.615–18.774, (²⁰⁷Pb/²⁰⁴Pb)_i = 15.708–15.793, (²⁰⁸Pb/²⁰⁴Pb)_i = 39.274–39.355)], these data are consistent with the involvement of component from subducted continental crustal sediment in their source region. The whole-rock Sr–Nd–Pb isotopic compositions exhibit linear trends between enriched mantle-derived mafic ultrapotassic magmas and relatively depleted crustal contaminants from the Lhasa terrane. The enrichment of the upper mantle below South Tibet is considered to result from the addition of components derived from subducted Indian continental crust to depleted MORB-source mantle during northward underthrusting of the Indian continental lithosphere beneath the Lhasa terrane since India–Asia collision at ~ 55 Ma. Secondary Ion Mass Spectrometry (SIMS) U–Pb zircon analyses yield the eruptive ages of 10.61 ± 0.10 Ma and 10.70 ± 0.18 Ma (weighted mean ages). Zircon Hf isotope compositions [Ɛ_Hf(t) = −4.79 to −0.17], combined with zircon O isotope ratios (5.51–7.22‰), imply an addition of crustal material in their petrogenesis. Clinopyroxene-liquid thermobarometer reveals pressure (2.5–4.1 kbar) and temperature (1029.4–1082.9 °C) of clinopyroxene crystallization, suggesting that depth of the magma chamber was 11.6–16.4 km. Energy-constrained assimilation and fractional crystallization (EC–AFC) model calculation indicates depth of assimilation and fractional crystallization in the region of 14.40–18.75 km underneath the Lhasa terrane, which is in consistent with depth of the magma chamber as suggested by clinopyroxene-liquid thermobarometer. Based on the whole-rock major and trace elements and Sr–Nd–Pb isotope compositions, combined with EC–AFC modeling simulations and zircon Hf–O isotope data, we propose that the YPVR resulted from assimilation and fractional crystallization (AFC) process of the K-rich mafic primitive magmas, which were caused by partial melting of the Indian continental subduction-induced mélange rocks.  相似文献   

陆相次火山岩型铜银矿床稳定同位素地球化学研究     

徐文炘  李蘅  李毅  陈民扬  庞春勇 《地球学报》2004,25(2):114-118

中国陆相次火山岩型铜银矿床分布广泛 ,银矿与酸性岩有关 ,铜矿与次英安玢岩有关。形成时代为燕山早、晚期。石英的δ18O值在 +7.9‰～ +16 .3‰之间 ,δ18OH2 O值在 - 3.0‰～ +8.1‰之间 ,δD在 - 5 5‰～ - 10 6‰之间。硫化物的δ3 4 S值在 - 9.8‰～ +9.6‰之间 ,硫化物的硫同位素富集顺序为δ3 4 SPy>δ3 4 SSp>δ3 4 SGn>δ3 4 SPo,硫化物矿物对平衡温度在 16 0～4 0 0℃ ,大多数溶液的硫同位素平均组成 (δ3 4 SΣS)为 +2‰～ +5‰ ,个别为 +2 0‰。  相似文献   

Petrological,chemical and depositional aspects of eastern Himalayan coals from elephant flat area,Kameng district,Arunachal Pradesh,India     

《International Journal of Coal Geology》1987,8(3):279-297

The eastern Himalayan coals of India associated with Permian (Lower Gondwana) sediments in the Kameng district of Arunachal Pradesh have petrographic and chemical properties differing from Peninsular Permian coals.The coals are moderately to highly crushed and have reached a semianthracitic stage. Macerals are highly reflecting and homogenized. Vitrinite and inertinite exhibit a crushing effect in the form of criss-cross fissures and cracks. Exinite is unidentifiable and has attained an inertinitic reflectivity. The Kameng coals are of high rank with average fixed carbon 88.75% and volatile matter 13.75% on d.a.f. basis. The reflectance values (R_o-max 2.02–2.31% in oil) of these coals are quite high with marked anisotropy.It is inferred that these peculiar coal properties have been attained due to prolonged tectonic disturbance in the area during the later Himalayan orogeny. The coal characteristics suggest that these coals were formed in a humid tropical climate within a deltaic regime. The depositional site experienced occasional marine influx due to tectonically controlled subsidence during peat accumulation.  相似文献   

广西栗木锡-铌-钽矿床中氟的作用及地表找矿评价标志   总被引：2，自引：0，他引：2  

覃宗光  姚锦其 《矿产与地质》2008,22(1):1-5

广西栗木多金属矿从上到下除有长石石英脉型锡-钨矿床、花岗伟晶岩脉型锡-钽-铌矿床外,还有含锡、铌、钽花岗岩原生矿床。本次对矿区内的地层、岩体、矿体中氟含量进行了研究并结合实验资料,认为燕山早期复式花岗岩体中富含的氟是成矿元素W、Sn、Nb、Ta的重要携带剂,对W、Sn、Nb、Ta从岩浆熔体中分出、迁移、富集及矿化分带起了重要作用,氟虽是寻找盲矿体的重要远程指示元素之一,但氟不是成矿元素,含矿岩体地表岩石中通常除有F、Be强异常外,W、Sn、Cu、Li等元素还会形成强异常组合;含矿岩体地表萤石-云母细脉带中硼（F）-般〉30000×10^-5,W（Be）〉1000×10^-6,W（Sn）〉300×10^-6,ω（W＋Sn）〉400×10^-6,F／（W＋Sn）和F／Sn〈110;含矿岩体地表长石石英脉带中W（F）〉10000×10^-6,ω（W）〉80×10^-6,W（Sn）〉500×10^-6,F／（W＋Sn）和F／Sn〈50;不合矿岩体的地表岩石及细脉带中各指标含量则与之相反。  相似文献   

广西北香铅锌锡矿区成矿地质及地球化学找矿前景评价     

黄世枝  秦来勇  曾志平  徐庆鸿 《矿产与地质》2008,22(3):227-231

文章从区域成矿背景、地层、构造等几方面探讨了矿床的成矿地质条件,指出NW向同沉积断裂对矿床的空间分布、产状等起主要控制作用,其次一级NW向断裂则是矿床的主要赋存构造,矿床的形成受地层岩性和构造双重控制。通过化探次生晕异常评价,圈定出北香一下大莫和莫四一南华两个呈NW-SE走向的综合矿化异常带。认为北香一下大莫异常带的走向延伸部位以及莫四一南华异常带的深部应具有一定的找矿潜力。  相似文献   

我国电气石矿产资源开发前景分析   总被引：1，自引：0，他引：1  

卢宗柳  许仲威 《矿产与地质》2008,22(6):562-565

电气石是近年来开发的重要的新型功能矿物材料。文章论述了我国电气石矿产的类型、成矿特点及电气石矿产产出时空分布特征,表明我国具有电气石矿产资源优势。同时介绍了电气石矿物功能特性和电气石应用产品,展现我国电气石资源开发应用前景。  相似文献   

Study on the modulating effect of polysaccharide upon the mineralization of iron hydroxide     

Jiangbo Huang  Zhenya Sun 《中国地球化学学报》2008,27(2):150-156

To investigate the modulating effect of polysaccharide upon the mineralization of iron hydroxide, a series of simulative biomineralization experiments using dextran and chitosan as organic substrates were conducted in this paper. The results showed that iron hydroxide gel nucleated and grew in polysaccharide molecules, with the self-assemble effect of dextran or chitosan, the nanometer-sized akaganeite was formed. The shape, size and crystal structural type of iron oxyhydroxide formed from iron hydroxide gel depend on the type of polysaccharide and its concentrations.  相似文献