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71.
新疆金矿床类型及找矿方向的研究   总被引:2,自引:2,他引:2  
彭守晋 《矿产与地质》1994,8(5):311-316
新疆金矿床划分为绿岩型、碎屑岩一碳酸盐岩-硅质岩型、变质碎屑岩型、火山岩型、侵入岩内及内外接触带型、伴生金及沉积型等7种类型,指出了火山岩型为区内最佳矿床类型,有很大的找矿前景.并探讨了地球化学场及地壳类型、构迟地质环境等方面对原生金矿床成矿的控制作用,提出了今后找金矿方向的建议.  相似文献   
72.
三山岛金矿F3断裂带的水文地质工程地质特征及灾害防治   总被引:2,自引:0,他引:2  
本文对三山岛金矿F3断裂带的构造、岩性和水动力学特征进行了研究,对矿坑开挖中的突水和坑道碎屑流的成因做了探讨,并在水文地质结构、水化学、水同位素及水文地热学的综合研究基础上,对未来的二期井下工程开挖中可能出现的工程地质问题进行了预测,提出了防治方案。  相似文献   
73.
张厚宏  唐先礼 《湖南地质》1991,10(4):307-310
衡山南岳岩体北侧,地质构造复杂,岩浆活动频繁,金矿成矿地质条件有利,已发现一个具有远景的金矿带,其中石子坳矿区为构造蚀变岩型金矿。本文简要地介绍了区域和矿区地质特征,总结出花岗闪长斑岩,硅化带和As元素化探异常等3条找矿标志,建议在该区开展大比例尺化探测量和地质填图,普查北西向硅化断裂破碎带,并对石子坳含金破碎带进行深部验证,寻找隐伏金矿床。  相似文献   
74.
The relationship of hillslope erosion rates and sediment yield is often poorly defined because of short periods of measurement and inherent spatial and temporal variability in erosion processes. In landscapes containing hillslopes crenulated by alternating topographic noses and hollows, estimates of local hillslope erosion rates averaged over long time periods can be obtained by analysing colluvial deposits in the hollows. Hollows act as local traps for a portion of the colluvium transported down hillslopes, and erosion rates can be calculated using the age and size of the deposits and the size of the contributing source area. Analysis of colluvial deposits in nine Oregon Coast Range hollows has yielded average colluvial transport rates into the hollows of about 35cm3cm?1yr?1 and average bedrock lowering rates of about 0.07 mm yr?1 for the last 4000 to 15000 yr. These rates are consistent with maximum bedrock exfoliation rates of about 0.09 mm yr?1 calculated from six of the hollows, supporting the interpretation that exfoliation rates limit erosion rates on these slopes. Sediment yield measurements from nine Coast Range streams provide similar basin-wide denudation rates of between 0.05 and 0.08mm yr?1, suggesting an approximate steady-state between sediment production on hillslopes and sediment yield. In addition, modern sediment yields are similar in basins varying in size from 1 to 1500 km2, suggesting that erosion rates are spatially uniform and providing additional evidence for an approximate equilibrium in the landscape.  相似文献   
75.
76.
李珍福  李学军 《铀矿地质》1994,10(6):360-366
壤中蜡样芽孢杆菌找矿法是微生物地球化学探矿方法之一。本文叙述了蜡样芽孢杆菌法的找矿原理、野外工作方法、室内测量技术、野外初步试验的地质效果以及测量中应注意的若干问题。在已知隐伏金矿床(点)和铀矿床(点)上测得了明显的蜡样芽孢杆菌计数异常,并在460铀(钼)矿床外围的铀矿化远景地段进行了试验,地质效果较为理想。  相似文献   
77.
岷礼东部-湘潭子一带蕴藏着甘肃省最大的金矿床和铅锌矿庆。主要控矿地层为中泥盆统,该套地层地球化学条件优越,断裂构造十分发育,岩浆活动非常强烈,是金及多金属矿床的有利成矿地段。区内矿床可划分为四大系列,6个类型。利用地球化学特征,分析主要控矿因素对成矿的控制作用;总结主要矿种的成矿规律;筛选出3个找矿远景区。  相似文献   
78.
Gold ore-forming fluids of the Tanami region, Northern Australia   总被引:1,自引:0,他引:1  
Fluid inclusion studies have been carried out on major gold deposits and prospects in the Tanami region to determine the compositions of the associated fluids and the processes responsible for gold mineralization. Pre-ore, milky quartz veins contain only two-phase aqueous inclusions with salinities ≤19 wt% NaCl eq. and homogenization temperatures that range from 110 to 410°C. In contrast, the ore-bearing veins typically contain low to moderate salinity (<14 wt% NaCl eq.), H2O + CO2 ± CH4 ± N2-bearing fluids. The CO2-bearing inclusions coexist with two-phase aqueous inclusions that exhibit a wider range of salinities (≤21 wt% NaCl eq.). Post-ore quartz and carbonate veins contain mainly two-phase aqueous inclusions, with a last generation of aqueous inclusions being very CaCl2-rich. Salinities range from 7 to 33 wt% NaCl eq. and homogenization temperatures vary from 62 to 312°C. Gold deposits in the Tanami region are hosted by carbonaceous or iron-rich sedimentary rocks and/or mafic rocks. They formed over a range of depths at temperatures from 200 to 430°C. The Groundrush deposit formed at the greatest temperatures and depths (260–430°C and ≤11 km), whereas deposits in the Tanami goldfield formed at the lowest temperatures (≥200°C) and at the shallowest depths (1.5–5.6 km). There is also evidence in the Tanami goldfield for late-stage isothermal mixing with higher salinity (≤21 wt% NaCl eq.) fluids at temperatures between 100 and 200°C. Other deposits (e.g., The Granites, Callie, and Coyote) formed at intermediate depths and at temperatures ranging from 240 to 360°C. All ore fluids contained CO2 ± N2 ± CH4, with the more deeply formed deposits being enriched in CH4 and higher level deposits being enriched in CO2. Fluids from deposits hosted mainly by sedimentary rocks generally contained appreciable quantities of N2. The one exception is the Tanami goldfield, where the quartz veins were dominated by aqueous inclusions with rare CO2-bearing inclusions. Calculated δ 18O values for the ore fluids range from 3.8 to 8.5‰ and the corresponding δD values range from −89 to −37‰. Measured δ 13C values from CO2 extracted from fluid inclusions ranged from −5.1 to −8.4‰. These data indicate a magmatic or mixed magmatic/metamorphic source for the ore fluids in the Tanami region. Interpretation of the fluid inclusion, alteration, and structural data suggests that mineralization may have occurred via a number of processes. Gold occurs in veins associated with brittle fracturing and other dilational structures, but in the larger deposits, there is also an association with iron-rich rocks or carbonaceous sediments, suggesting that both structural and chemical controls are important. The major mineralization process appears to be boiling/effervescence of a gas-rich fluid, which leads to partitioning of H2S into the vapor phase resulting in gold precipitation. However, some deposits also show evidence of desulfidation by fluid–rock interaction and/or reduction of the ore-fluid by fluid mixing. These latter processes are generally more prevalent in the higher crustal-level deposits.  相似文献   
79.
天马山硫金矿床金的赋存状肪及分布规律   总被引:2,自引:3,他引:2       下载免费PDF全文
矿床中金主要以独立矿物相存在,少数为细粒分散相,金的载体矿物主要有黄铜矿,毒砂,黄铁矿,综合脉石和磁黄铁矿等,金矿物主要为自然金,银金矿,平均成色745.57,金的嵌布类型有粒间金,包裹金,裂隙金3种,金在矿石中及不同矿体中的分布不均匀,金与流,金与砷的相关性因矿体类型及矿石类型的不同而有差异。  相似文献   
80.
青海铜厂沟金矿床围岩蚀变特征与矿化   总被引:1,自引:1,他引:1  
李时新 《矿产与地质》2001,15(2):98-101
铜厂沟金矿床围岩蚀变强烈,并受构造脉动的控制,蚀变具不规则环形分带;蚀变作用划分为硅化-绿泥石化、硅化-碳酸盐化、黄铁矿化和硅化-黄铁矿化等四阶段,金矿化发生在黄铁矿化阶段。根据围岩蚀变特征,在已知矿体的下部,可以寻找构造-蚀变岩型金矿体。  相似文献   
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