云南白秧坪-华昌山矿带构造特征及其控矿作用

云南白秧坪-华昌山成矿带位于兰坪-思茅印支燕山、喜马拉雅期成矿带的北段,成矿以中生代海相过渡到陆相的碳酸盐岩建造、碎屑岩建造夹火山岩建造为基础,喜马拉雅期构造推覆及热液改造为主导作用。对矿带内矿田地质和控矿构造的调查表明,本区的层控加热液改造型矿床与成矿构造关系密切。      

成矿系统分析与新类型矿床预测

新类型矿床的发现常能带来矿产储量的巨量增长 ,是新世纪中保障矿产资源供应的一个重要途径。成矿系统分析对发现新类型矿床有重要意义。 (1)掌握一个区域成矿系统中各矿床类型间相互关系 ,由已知矿床类型找寻未知矿床类型 ,这已在长江中下游成矿带的找矿历史中得到证实。 (2 )认识成矿系统的空间结构 ,主要是垂向分带 ,有助于找寻深部的隐伏矿床类型。 (3)查明成矿系统的时间结构 ,包括成矿过程中矿床类型的迭变关系 ,可由已知矿化链条查找缺失的矿化链条 (矿床类型 ) ,这在岩浆热液成矿系统中常能奏效。 (4 )查明成矿系统中矿床类型多样性的制约因素 ,可据此分析相关区域中发现新类型矿床的潜力。 (5)研究新的成矿环境和新的成矿作用 ,从而发现新的矿床类型。在生物成矿系统、深海成矿系统、低温成矿系统、构造成矿系统及叠加成矿系统中有更大的发现新类型矿床的几率。文中提出近期内可能发现的新的铂族元素矿床类型。笔者还指出今后的找矿目标 ,应是整个成矿系统 ,而不是局限于单个矿床及单个矿床类型 ,这样才可能不失去发现新类型矿床的机会。     

重新认识和划分矿床类型——隐伏岩金矿体定位预测的一个重要前提

目前流行的岩金矿床分类方案是依据地表已遭受一定剥蚀的矿床地质特征和成因理论而建立的 ,为了有效地开展隐伏岩金矿体定位预测工作 ,必需重新认识和划分矿床类型 ,弄清哪些特征真正具有可比性。文中分析了现有分类方案中几个亟待解决的问题 ,结合金矿的“特殊性” ,提出应简化矿床类型、将成矿区带作为分类的目标 ,将成矿系统作为分类的基础。     

分形-判别非线性数学模型及勘探线剖面致矿地质异常分析

判别分析模型是多变量线性统计模型,但自然界更多现象是非线性的。通过将非线性科学中分形几何学与传统的判别分析模型相结合导出分形－判别非线性数学模型,并应用于某铜金矿床勘探线剖面的致矿地质异常分析中,与传统的判别分析方法相比,明显地提高了判对率。     

综合物化探方法在朱拉扎嘎金矿的应用

朱拉扎嘎金矿 ,经综合物化探普查 ,在大面积覆盖区发现 0 .5km2 高视极化率、中低视电阻率激电异常和低缓磁异常。已施工的 8个钻孔均见矿 ,估算黄金储量大于 30t。沿走向 ,激电异常在北东、南西两端有大幅度向外延伸趋势 ,可能是深部硫化物矿层向外延伸的反映。     

Spatial and Temporal Distribution of Au and Pb-Zn Mineralization: Phenomenon, Mechanism and Implication

In the 1990s, some median-large gold deposits have been discovered in several lead-zinc metalloge-netic belts (e.g. the Qinling lead-zinc metallogenetic belt, Shanxi Province and Gansu Province and the Qingchengzi lead-zinc ore field, Liaoning Province) in China. Gold deposits and lead-zinc deposits spatially co-exist in the same tectonic setting; lead-zinc orebodies are commonly located below gold ore bodies. The host rocks of lead-zinc ore-bodies are conformably overlain by those of gold ore bodies. The age of gold mineralization is obviously younger than that of lead-zinc mineralization. Preliminary geochemical research has demonstrated the following: lead-zinc mineralization took place in a marine sedimentary-exhalative system, which had the characteristics of a high fluid/rock ratio, a high salinity and a high halide activity; meanwhile, most of gold was transported into the low-temperature hydrothermal plume and primarily enriched in sediments. During later (magmatism-) metamorphism-tectonism, gol     

Helium, Argon, and Xenon Isotopic Compositions of Ore-formingFluids in Jinding-Baiyangping Polymetallic Deposits,Yunnan, Southwest China

The Jinding superlarge lead and zinc deposit has attracted the attention of geologists of the world and its metallogenesis has long been in dispute. This paper takes the Jinding deposit and the Baiyangping Cu-Ag-Co deposit which was recently found at about 30 km north of Jinding as one ore belt, and, based on researches on the helium, argon, and xenon isotopic compositions of primary inclusions in ore-forming solutions of the main stage, the authors have found that the 3He/4He ratio of the ore-forming fluid is 2.7′ 10- 6 (varying from 0.19 to 1.97 Ra), the 4He/40Ar ratio (0.24- 3.12) is close to the mantle characteristic ratio, and the xenon isotopic composition and evolution show characters of the mantle xenon. The above results reveal the characteristics of mantle source and crust-mantle fluid mixing (mantle helium reaching 32%) and the metallogenic contributions of the deep processes in the Jinding-Baiyangping ore belt.     

Classification, M inerogenic Models and Prospecting of Realgar/Orpiment Deposits in China

China's realgar/orpiment deposits may be classified into three types, the stratabound, hot-water sedimentary and hydrothermal, according to their mineralizing processes, geological occurrences, tectonic and geochemi-cal features. The three types may be further distinguished into seven subtypes, namely, the Xiaguan, Shuiluo, Jiepaiyu, Songpan, Shixia, Wangzhuang and Ninghshan ones. On this basis three minerogenic models are established, and based on studies of their geochemistry and minerogenic mechanisms the prerequisites for prospecting for these types of deposits are given in the paper.     

云南省金矿区域成矿特征及构造成矿区划

云南省金矿区域成矿特征主要表现在 :(1)构造 -热动力条件控矿的明显性 ;(2)成矿时间的长期性和成矿期的滞后性 ;(3)金矿床类型的多样性 ;(4)金矿床空间分布的集中性。作者分析上述区域成矿特征之后 ,对云南省金的构造成矿区 (带 )进行了初步划分。划分了2个构造成矿域 ;5个构造成矿区 (带 ) ;12个金成矿区 (带 )。     

兰坪白秧坪铜银多金属矿床流体地球化学特征及成矿机制探讨

白秧坪铜银多金属矿床主要产于白垩系下统景星组石英砂岩、粉砂岩中 ,矿体受一组北东向的压扭性断层控制而呈似层状、脉状产于断裂带中。包裹体分析表明成矿流体为低温 (平均124～141℃ )、低矿化度的盆地卤水 ,流体的H、O同位素组成位于大气降水线附近 ,反映了水 /岩作用程度较低、水 /岩反应时限短 ,流体流动与循环速度较快。计算机模拟结果表明在景星组沉积之后的13～16Ma期间断裂作用所产生的断裂渗透性达到最大 ,此期间流体演化的温度也达到125～140℃。断裂作用所产生的高断裂渗透性对周围地层中的流体产生泵吸作用并形成流体流动的断裂引水渠 ,从而导致大量流体在断裂带中快速流动、循环和汇聚成矿