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1.
The Chalukou porphyry Mo deposit, located in the northern Great Xing'an Range, is the largest Mo deposit in the Xing'an–Mongolia orogenic belt. Its ore bodies are mainly hosted in the intermediate-felsic complex and Jurassic volcanic sedimentary rocks, of which Late Jurassic granite porphyry, quartz porphyry and fine-grained granite are closely associated with Mo mineralization. The Middle Jurassic monzogranite belongs to shoshonite series, with SiO2 and Al2O3 contents of 69.48 to 74.98% and 12.35 to 14.48%, respectively. The total alkali (K2O + Na2O) content ranges from 7.67 to 10.42%, with K2O/Na2O ratios between 1.07 and 2.81. These rocks are strongly enriched in Rb and K but are depleted in Ta, Nb, P and Ti, with negative Eu anomalies and positive εHf(t). The Late Jurassic granite porphyry, quartz porphyry and fine-grained granite are shoshonite or high-K calc-alkaline series. Their SiO2 and Al2O3 contents range from 73.87 to 78.95% and 10.35 to 13.47%, respectively. The total alkali (K2O + Na2O) contents range from 8.06 to 10.02%, with K2O/Na2O ratios from 1.03 to 8.20. These rocks are strongly enriched in Rb, K and Th, but are depleted in P, Ti, Ba and Sr, indicating clear negative Eu anomalies and positive εHf(t). The Middle–Late Jurassic granitoids in the Chalukou deposit are highly fractionated I-type granitoids, and derived from juvenile lower crust materials that originated from the Neoproterozoic depleted mantle. These granitoids formed in the extension tectonic setting of the post-collision stage of the Mongol–Okhotsk orogenic belt, probably superposed by the back-arc extension related to the subduction of the Paleo-Pacific Plate. 相似文献
2.
会泽超大型富锗银铅锌矿床是川—滇—黔铅锌多金属成矿区滇东北矿集区的典型代表。基于大量的地表调研和坑道精细编录,通过赋矿白云岩的岩石学、地球化学与矿化蚀变分带规律、构造对矿化-蚀变带控制作用的研究,认为赋矿粗晶白云岩是成矿过程中白云石化的产物,具有典型的热液蚀变成因,与沉积-成岩成因的摆佐组细晶白云岩、白云质灰岩明显不同;根据矿石和蚀变围岩中铅锌矿物组成与矿化、蚀变程度及其分布特征,该矿床矿化-蚀变分带规律:从矿体到围岩依次为铅锌矿石—铅锌矿化黄铁矿带→铅锌矿化/黄铁矿化粗晶白云岩带→灰白色粗晶白云岩带、米黄色粗晶白云岩带、肉红色粗晶白云岩带、网脉状白云石化灰岩带(蚀变残留体)、弱白云石化灰岩带。矿化-蚀变带明显受冲断褶皱构造(矿山厂、麒麟厂、银厂坡斜冲断层及其派生褶皱)上盘的层间断裂带控制,形成了典型的"成矿构造-蚀变白云岩-铅锌矿体"的矿化结构。该认识不仅丰富了会泽型(HZT)铅锌矿床成矿理论,而且对指导滇东北铅锌矿集区,乃至川滇黔成矿区的资源危机矿山的综合地质研究与找矿勘查具有重要的现实意义。 相似文献
3.
The Tethyan domain from China to Iran hosts many important sediment-hosted Pb–Zn deposits but most have been poorly documented. This study summarizes the salient features of these deposits and discusses the type of ore, tectonic setting, and important ore controls, on the basis of new geological observations and previous publications. The Tethyan domain is characterized by the young and extensive Himalayan–Tibetan and Zagros orogens that formed through collisions between the India/Arabia and Eurasia continents since the Late Cretaceous or early Cenozoic. Abundant Mississippi Valley-type (MVT) and subordinate clastic-dominated (CD, also known as SEDEX) Pb–Zn deposits occur in this domain, including in central and eastern Himalayan–Tibetan orogen in China, the Indian passive margin in southern Pakistan, and various tectonic units of Iran. Economically important deposits contain 0.1–21 Mt Pb + Zn and have total metal resources of ∼75 Mt with ∼48% being oxidized ores. All major deposits known in this domain are MVTs (i.e., the Jinding, Huoshaoyun, Mehdiabad, and Angouran deposits).Mississippi Valley-type Pb–Zn deposits occur in continental-collision-related fold-and-thrust belts and forelands, where deposits are mostly located on the margin of the Eurasian continent, with some in the Indian and Arabian continental margins. Clastic-dominated Pb–Zn deposits occur in central Iran and southern Pakistan, hosted by deep-water siliciclastic sequences of the early Cambrian rifted continental margin of Gondwana and the Jurassic passive continental margin of India, respectively. The youngest mineralized rocks and ages constrain that some important MVT deposits (e.g., the Jinding, Chaqupacha, and Angouran deposits) were formed after a main phase of regional compression, during a regional, large-scale strike-slip or crustal-extension stage in a continental collision setting. In sense of lithologic structure, important ore controls for MVT deposits include evaporite diapir structure, carbonate/evaporite dissolution–collapse structure, pre-existing barite, and porous dolostone. Much of the primary sulfide ore in this domain has been oxidized by supergene processes. This is particularly pronounced in the newly discovered Huoshaoyun deposit, where almost all sulfides have been oxidized to smithsonite and cerussite. An understanding of tectonic setting, ore controls, and supergene processes is essential in exploring for MVT deposits in this domain. 相似文献
4.
雪岭矿区位于康滇地轴云南段东川矿区南缘,区内主要出露震旦系和寒武系沉积地层,其浅部可见铜多金属脉状矿化沿断裂带和辉绿岩脉产出,深部勘探发现了全隐伏在陡山沱组中的层状铜矿。铜矿化以黄铜矿、斑铜矿为主,呈浸染状、网脉状、薄层状和星点状赋存于深灰色破碎状白云岩、黑色炭泥质岩和石英脉中,矿体具明显沉积及热液叠加改造特征。常量元素分析显示岩矿石SiO2、Fe2O3、FeO、K2O等含量较高,而Na2O、CaO和MgO含量偏低;微量元素分析显示围岩Cu、Pb、Zn、Ag元素含量较高,富集U、Y等元素,亏损Nb、Zr、Ti、Yb等高场强元素和Sr,矿石样品则富集U、Nd等高场强元素,亏损Ba、K、Sr等大离子亲石元素和Nb;球粒陨石标准化的稀土元素配分模式为轻稀土富集、重稀土亏损的右倾形态,且呈现出铕的强烈亏损。陡山沱组改造型脉状矿体方解石和黄铁矿样品δDV-SMOW值分别为-137.3×10-3和-110.2×10-3,δ18O水值分别为-11.3×10-3和-1.29×10-3,显示成矿流体来源于大气降水形成的层间封存水;矿石富集重硫,硫主要来源于海相硫酸盐的还原作用,部分受到深部昆阳群古铜矿床硫和生物硫的影响;铅来源于放射性成因铅较高的源区,具壳幔混合铅的特征,且矿石、围岩、昆阳群古铜矿的铅同位素组成具一定亲缘性,显示成矿物质主要来源于下伏昆阳群古铜矿,部分来源于围岩。综合研究认为,该铜矿与滥泥坪矿区所含陡山沱组铜矿相似,均为昆阳群古铜矿残余风化壳在海解作用下铜质析出,在成岩及构造作用下活化迁移并沿炭泥质还原性岩石、石英脉及构造有利位置沉淀富集所致。本区找矿重点应为深部陡山沱组铜矿以及下伏昆阳群古铜矿床。 相似文献
5.
The Chalukou giant porphyry Mo deposit, located in the northern Great Xing'an Range, is the largest Mo deposit in the Xing'an–Mongolia orogenic belt. This deposit's ore bodies are mainly hosted in an intermediate–felsic complex and Jurassic volcanic sedimentary rocks, of which Late Jurassic granite porphyry, quartz porphyry and fine grained granite are closely associated with the Mo mineralization. Three types of fluid inclusions (FIs) are present in the quartz associated with oxide and sulphide minerals, i.e., liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing multiphase FIs. The FIs in the quartz phenocrysts of the granite porphyry contain liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing multiphase FIs. The homogenization temperatures vary from 230 °C to 440 °C and 470 °C to 510 °C, and their salinities vary from 0.7% to 53.7% NaCl eq. and 6.2% to 61.3% NaCl eq., respectively. The FIs of K-feldspar–quartz–magnetite veins of the early stage are composed of liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing multiphase FIs with homogenization temperatures and salinities of 320 °C to 440 °C and 4.2% to 52.3% NaCl eq., respectively. The FIs of quartz–molybdenite veins and breccia of the middle stage are composed of liquid-rich two-phase, gas-rich two-phase and daughter mineral-bearing multiphase FIs with homogenization temperatures and salinities of 260 °C to 410 °C and 0.4% to 52.3% NaCl eq., respectively. FIs of quartz–fluorite–galena–sphalerite veins of the late stage are liquid-rich two-phase FIs with homogenization temperatures and salinities of 170 °C to 320 °C and 0.5% to 11.1% NaCl eq., respectively. The ore-forming fluids of the Chalukou deposit are characterised by high temperature, high salinity and high oxygen fugacity, belonging to an F-rich H2O–NaCl ± CO2 system. The δ18OW values vary from − 4.5‰ to 3.2‰, and the δDW values vary from − 138‰ to − 122‰, indicating that the ore-forming fluids were a mixture of magmatic and meteoric water. The δ34S values range from − 1.9‰ to + 3.6‰ with an average of + 1.6‰. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values of the metallic minerals are in the ranges of 18.269–18.501, 15.524–15.567 and 38.079–38.264, respectively. Both the S and Pb isotopic systems indicate that the ore metals and fluids came primarily from a deep-seated magma source from the juvenile lower crust. The Mo mineralization in the Chalukou deposit occurred at a depth of 0.5 to 1.3 km, and multiple stages of phase separation or immiscibility of ore-forming fluid was critical for the formation of the Chalukou deposit. 相似文献
6.
岔路口超大型斑岩钼矿床位于大兴安岭北部,是目前中国东北地区最大的钼矿床,矿体赋存于中酸性杂岩体及侏罗系火山-沉积岩内,其中花岗斑岩、石英斑岩、细粒花岗岩与钼矿化关系密切.流体包裹体研究表明,岔路口矿床主要发育富液两相包裹体、富气两相包裹体和含子矿物多相包裹体.花岗斑岩石英斑晶中流体包裹体的形成温度集中在230 ～ 440℃和470～510℃两个温度区间,盐度分别介于0.7％ ～ 53.7％ NaCl eqv和6.2％～61.3％ NaCl eqv两个区间;成矿早阶段钾长石-石英-磁铁矿脉中流体包裹体的形成温度集中在320～440℃、盐度介于4.2％ ～ 52.3％NaCl eqv;成矿中阶段石英-辉钼矿脉和角砾岩中流体包裹体的形成温度集中在260～410℃、盐度介于0.4％～52.3％ NaCleqv;成矿晚阶段石英-萤石-方铅矿-闪锌矿脉中流体包裹体的形成温度集中在170～320℃、盐度介于0.5％ ～ 11.1％ NaCleqv.成矿流体具高温、高盐度及高氧逸度的特征,总体上属于富F的H2O-NaCl±CO2体系.成矿流体的δ 18Ow值为-4.5‰～3.2‰,δDw值为-138‰～-122‰,表明成矿流体为岩浆水与雨水的混合流体.金属硫化物的δ34S值介于-1.9‰～+3.6‰,均值为+1.6‰,表明成矿物质主要来自深源岩浆.多期次的流体沸腾作用是该矿床的主要成矿机制. 相似文献
7.
利用宏观县区政府统计资料和定性个案访谈资料,对滇桂边境地区跨境通婚进行调查分析,结果发现：滇桂边境地区跨境通婚数量在不断增长,地理通婚圈由边境向内地延伸,通婚辐射范围越来越广,一部分跨境婚姻即将演变为内地跨国婚姻;婚入人口性别结构严重失衡,边境国家女性嫁入中国的数量远远多于中国边境女性嫁到邻国;跨境婚姻中夫妇双方整体教育文化素质偏低,多以小学和初中为主,呈现出教育资源的弱弱结合;跨境通婚的结婚登记率较低,大多以“事实婚姻”的方式在中国组成家庭,并且这些家庭早婚多育现象比较严重,不利于中国计划生育的有序执行;夫妇年龄差偏大以及跨境通婚具有代际传承等特征。进一步分析发现：导致滇桂边境地区的跨境通婚不断增长的原因与地理空间的邻近性、跨境民族文化圈子的同源性、等级通婚圈的封闭性、边境邻国→中国边境→中国内地的二级经济阶梯推动性、中越两国人口性别结构的互补性、不同国家婚姻制度“错位性”和边境地区政治形势的不稳定性存在密切的关系。 相似文献
8.
在井巷工程中探明前方或周边涌水是十分必要的。以云南彝良毛坪矿区为例,利用等值反磁通瞬变电磁法(OCTEM)和音频大地电磁法(AMT),探测了帷幕注浆工程轴线以下700 m范围内的含水断裂带的发育情况,意图为帷幕注浆治水工程提供指导意见。通过物探综合分析,探明具有富水性的异常7个。本项研究结果表明,OCTEM法能够识别出较小的含水节理或裂隙,AMT法对大深度含水破碎带较为敏感,两者结合对不良含水地质体探测效果明显。由此可见,综合物探在帷幕注浆治水中应用效果较好,有效查明了含水通道的深部延伸,为帷幕注浆治水提供了目标靶区。 相似文献
9.
大兴安岭北段岔路口斑岩钼矿床成矿年代学、岩石地球化学及其地质意义 总被引：1，自引：0，他引：1
黑龙江省岔路口超大型斑岩钼矿床位于大兴安岭北部,是目前中国东北地区最大的钼矿床,矿体赋存于中酸性杂岩体及侏罗系火山-沉积岩内,其中,晚侏罗世花岗斑岩、石英斑岩、细粒花岗岩与钼矿化关系密切。6件辉钼矿样品的铼-锇等时线年龄为（148±1）Ma。中侏罗世二长花岗岩属钾玄岩系列,w（SiO2）为69.48% ~ 74.98%,w（Al2O3）为12.35%~14.48%,w（K2O+Na2O）为7.67%~10.42%,K2O/Na2O比值介于1.07~2.81。轻、重稀土元素分馏较强,具有较弱的铕负异常,HFSE和LILE分异明显,Rb、K等元素富集,Ta、Nb、P、Ti等元素亏损,显示正εHf（t）值;晚侏罗世花岗斑岩、石英斑岩属钾玄岩系列,而细粒花岗岩属高钾钙碱性系列,w（SiO2）为73.87%~78.95%,w（Al2O3）为10.35%~13.47%,w（K2O+Na2O）为8.06%~10.02%,K2O/Na2O比值介于1.03~8.20。轻、重稀土元素分馏较强,具有明显的铕负异常,HFSE和LILE分异明显,Rb、K、Th等元素富集,P、Ti、Ba、Sr等元素亏损,显示正εHf（t）值。二长花岗岩、花岗斑岩、石英斑岩及细粒花岗岩均为高硅、富碱的高分异I型花岗岩,岩浆源区组成类似,主要来自于新元古代期间亏损地幔增生的年轻下地壳物质。岔路口斑岩钼矿床是晚侏罗世大陆内部构造-岩浆活化的产物,形成于蒙古-鄂霍次克造山带后碰撞伸展环境,同时,可能受到古太平洋板块俯冲诱发的弧后伸展作用的叠加。 相似文献
10.
云南人口城市化与土地城市化耦合协调发展研究 总被引：2，自引：0，他引：2
从人口城市化质量与土地城市化质量两方面，构建人口城市化与土地城市化耦合协调发展评价指标体系。以2007~2016年相关数据为支撑，定量计算云南省多年人口城市化与土地城市化耦合度、综合发展指数和协调发展度，并根据协调发展类型划分标准对研究时段内云南人口城市化与土地城市化的协调发展类型和对比类型进行划分，并在此基础上对二者的协调状态进行评估；同时在GIS技术支持下，分别以2007年和2016年为时间节点，揭示不同时段云南省各市（州）人口城市化与土地城市化协调发展的空间格局特征与空间格局的变化特征。研究表明：从时间序列特征看，云南自2010年起土地城市化快于人口城市化，土地规模扩展过快，存在造成空城的风险；城市化水平总体发展趋势良好，人口与土地之间的相互依赖程度高；人口城市化与土地城市化协调发展趋势良好，逐步进入协调阶段；从空间格局特征看，呈现以昆明为中心，从中部“协调型”逐步转变为边缘“失调型”的空间格局；土地城市化滞后型数量少，且集中分布于滇中和滇西北地区；人口城市化滞后型数量多，广泛分布于滇东、滇西、滇南和滇东北的大部分地区；各市（州）协调发展状态分属协调阶段、磨合阶段和失调阶段，协调发展对比类型空间差异显著。 相似文献