齐波夫分布律与阻尼曲线在夹皮沟金矿田成矿预测中的应用   总被引：2，自引：0，他引：2  

綦远江  薄继荣等 《地质与勘探》2002,38(1):35-39

用齐波分布律和阻尼曲线现象进行矿产资源预测，具有采用数据少，计算方法简单的特点，与元素丰度模型法，黎彤法等方法预测的结果基本相当，夹皮沟金矿田是一研究程度与开采程度都很高的地区，运用齐波夫分布律和阻尼曲线现象对其进行预测，夹皮沟金矿田仍有500t左右的潜在资源量，找矿潜力达74％，尤其是沿主剪切带附近，仍有大型，超大型矿床隐伏，只是勘探深度要大大增加。  相似文献   

Productivity optimisation in weak sedimentary formations for improved coal production and roof stability—an approach     

V. M. S. R. Murthy  Santosh Kumar Ray 《Geotechnical and Geological Engineering》2002,20(3):273-290

Far-field peak particle velocity (PPV) measurements were made in the roof while blasting in coal development drivages at Tandsi Mine, Western Coalfields Limited, India. The roof was fragile at this mine and was posing constant support problems for mining, resulting in low productivity. The PPV measurements have been used to decipher the damage zone in the roof. The extent of damage obtained has been compared to establish the threshold limits for the damage zone. Conversely, the maximum charge per delay that can be exploded is calculated and a suitable blast design has been recommended for maintaining the roof stability and pull. A roof vibration predictor equation has been developed that shows a consistent trend indicating that it may have future use in a similar geo-mining setup. The blast pattern recommended has reduced the damage extent, though marginally, but helped in improving pull. Critical PPV for incipient rock damage in underground coal mine development drivages under fragile roof were computed. The PPV level for incipient crack growth was found to vary from 500 to 800 mm/s while for overbreak it varied from 800 to 1200 mm/s. It was also observed that the location of cut holes, charge concentration and firing sequence were found to be responsible for the difference in their damage potential.  相似文献   

湘东地区金与相关元素的背景含量及其演化     

伏庆是  胡能勇等 《湖南地质》2002,21(1):7-11

湘东地区，除斑岩外，金在各类岩石地层中的背景含量一般都小于地壳金丰度值，各时代地层和岩浆岩中的金背景含量虽有不同，但不存在显著差异。中元古代 与早古生代出现两次金的高含量期，古生代以后金的背景含量缓慢降低；随着时代由老至新，地层中与金相关的元素组合趋向单一；相关程度也逐渐减弱。湘东地区金与相关元素的背景含量及演化特征表明，该区不存在金的矿源层或矿源岩，金矿化主要与断裂活动有关。  相似文献   

芙蓉矿田锡矿化强度垂直分布特征及其找矿意义   总被引：3，自引：0，他引：3  

刘东宏  田旭峰  陈民苏  许以明 《湖南地质》2002,21(2):115-118

引入矿化度的概念,=(矿体长度)·(平均厚度)·(平均品位),计(A)ALMC算并介绍了芙蓉矿田锡矿化强度的垂直分布特征,指出锡矿化集中分布在上、中、下个平台3(～、～、-～标高段),并对其在矿产资源量预测中的应用作了7001 300 m350700 m20350 m探讨,预测该矿田锡资源总量达×n102万t。  相似文献   

矿业开采诱发的地质环境负效应及综合治理工程   总被引：2，自引：1，他引：2  

王凤生 《吉林地质》2001,20(1):35-44

采矿必然扰动环境，诱发各种各样的地质环境负效应；西方发达国家已实行了矿山环境保护和治理工作；中国作为发展中国家，矿山环境综合治理工程对我国矿产资源的可持续开发具有重要意义。  相似文献   

Geo–tectonic Position of Tin Polymetallic Mineralization Zone in the Southern Da Hinggan Mountains Area, Inner Mongolia, China: An Introduction to This Special Issue     

Shihua SUN  Shin–ichi AKIYAMA 《Resource Geology》2001,51(4):275-282

Abstract: As a part of the main activities of Japan‐China technical cooperation project, a test survey area, approximately 5,000 km², was established for the implement of its geological and geochemical research program. A major mineralization zone called Huanggang–Ganzhuermiao–Wulanhaote Sn‐Cu polymetallic mineralization zone is recognized in the southern Da Hinggan Mountains area. The southern half of this zone is known as the sole Sn‐mineralization zone in North China. The survey area lies in this prominent zone. As the most of the papers presented in this issue have concerns to the geology and mineralization in this survey area, this report was prepared to introduce geo‐tectonic situation of the Sn‐Cu polymetallic mineralization zone in the Inner Mongolia orogenic belt. The belt is divided into four tectonic facies (from NW to SE); I: Wuliyasitai volcano‐plutonic zone, II: Hegenshan ophiolite mélange zone, III: Sunitezuoqi volcano‐plutonic zone, IV: Wenduermiao ophiolite mélange zone. The subject Sn‐Cu polymetallic mineralization zone is situated in the southeastern part of the Sunitezuoqi magmatic zone. About this Sunitezuoqi magmatic zone, three geo‐tectonic characteristics are pointed out. In late Carboniferous to early Permian period, subduction of Hegenshan oceanic crust occurred, which accelerated volcano‐plutonic activities and brought about basic to intermediate volcanic rocks of tholeiitic to calc‐alkaline series represented by Dashizhai Group in the Sunitezuoqi magmatic zone. Late Jurassic to early Cretaceous acidic rocks representing the most culminated volcanism and plutonism in Mesozoic era in the Da Hinggan Moutains area are distributed very extensively in and around the Sn‐Cu polymetallic mineralization zone. The Proterozoic metamorphic basement rocks called Xilinhaote complex are distributed close to the mineralized area in the Sunitezuoqi magmatic zone. Although the real mineralization was known associated with Mesozoic acidic to intermediate volcano‐plutonic activities, it is thought that the lower Permian Dashizhai volcanic rocks and pre‐Cambrian basement rocks might have played certain significant role in the process respectively of extraction of elements and formation of the magma favorable for such mineralization in the Sunitezuoqi magmatic zone. It would be necessary to give further considerations to these three geological units in relation to the Sn‐Cu polymetallic mineralization.  相似文献   

Generation and Evolution of Ore Fluids for Porphyry Cu-Au Mineralization of the Santo Tomas II (Philex) Deposit, Philippines   总被引：1，自引：0，他引：1  

Akira IMAI 《Resource Geology》2001,51(2):71-96

Abstract: The Santo Tomas II (Philex) deposit is a porphyry Cu‐Au deposit, located in the southern part of the Baguio mineral district, Benguet Province, northern Luzon, Philippines. The Santo Tomas II deposit is associated with an intrusive complex consisting of four rock types that are distinguished based on petrography. They are 1) post‐ore clinopyroxene‐bearing hornblende andesite porphyry, 2) ore‐generating hornblende andesite porphyry, 3) hornblende quartz diorite porphyry and 4) porphyritic hornblende quartz diorite. K‐Ar age of hydrothermal biotitization was estimated to be 1.5±0.4 Ma. A number of intrusive bodies having broadly similar petrography and K‐Ar age occur in the vicinity of the Santo Tomas II deposit, such as at Clifton, Ligay (Binang), Bumolo (Waterhole) and Philex Main Camp areas. The intrusions at the Santo Tomas II deposit and in the vicinity are characterized by high X_Mg (Mg/[Mg+Fe] atomic ratio, about 0.7 or higher) of mafic silicate phenocrysts such as hornblende, and high sulfur contents (> 0.2 wt% as SO₃) in accessory microphenocrystic apatite, suggesting a highly oxidizing condition. Sulfur is accommodated dominantly as oxidized species since the crystallization of phe‐nocrysts. Sub‐dendritic rim of tremolitic amphibole on hornblende phenocryst in the ore‐generating andesite porphyry at the Santo Tomas II deposit suggests interaction of magma and aqueous fluid(s) exsolved due to decompression during intrusion. Dissemination of magnetite is associated with hydrothermal biotitization and is followed by sheeted and stockwork quartz veinlets having silician magnetite and rare titanohematite instead of Cu‐Fe sulfides. The silician magnetite‐rich quartz veinlet was formed at f_O2 near the hematite‐magnetite buffer at nearly magmatic temperature, where sulfur dominantly existed as oxidized species such as SO₂. Chalcopyrite and bornite, which commonly exhibit micrographic texture often accompanying Pd telluride and native gold/Au‐rich electrum, are associated with subsequent anhydrite (‐quartz) veinlets and stringers. Both intermediate solid solution (iss) and bornite solid solution (bnss) are thought to have coprecipitated primarily at above 500°C based on fluid inclusion microthermometry and sulfur isotope thermometry applied for anhydrite and associated chal‐copyrite and bornite. The initial iss is considered to have converted to chalcopyrite partly replacing bnss during cooling. The hypersaline polyphase fluid inclusions abundantly found in the sheeted and stockwork quartz as well as anhydrite veinlets with scarce gaseous inclusions suggest that they have been trapped in the two aqueous fluid immiscible region. The western Luzon arc associated with porphyry Cu mineralization is characterized by oxidized hydrous magmatism and shallow emplacement, and by the source of sulfur enriched in ³⁴S.  相似文献   

Predictive modelling of dump water impact on the surroundings of the lignite dump site Jänschwalde (Eastern Germany)     

Nils Hoth  Steffen Wagner  Frieder Hfner 《Journal of Geochemical Exploration》2001,73(2)

Open cast mining of lignite leads to dumps containing highly mineralised pore waters. To predict the impact of the dump waters on the undisturbed aquifers two steps are necessary. (1) The prediction of dump water quality at times when steady state flow conditions will be established. (2) The simulation of the dump ground water migration with a model that is able to handle the complexity of the homogeneous and heterogeneous interactions of the migration process.For the investigated site Jänschwalde, which is still dewatered, a chemical mass balance was performed. The predicted alkalinity potentials exceed acidity potentials for the dump as a whole. The distribution of these parameters show high alkalinity potentials for the northern part.In order to model the migration process the transport code PCGEOFIM^® [Anwenderdokumentaion, IBGW Leipzig, (in German)] was coupled with the geochemical equilibrium code PHREEQC [USGS, Water-Resources Investigations Report]. This was done to simulate redox reactions, mineral dissolution and precipitation, and cation exchange in the ground water zone. The model is verified by a column flow test. The results of the simulations show a small effect of the migrating dump waters on the quartenary aquifer with respect to acidity changes. This results from calcite buffering and cation exchange. The impact on the quartenary aquifer by sulphate is much higher.  相似文献   

量化评价指标的自动统计算法研究   总被引：2，自引：1，他引：2  

夏玉成 《煤田地质与勘探》2001,29(1):25-27

为了能使矿井构造量化预测技术在更多的矿井中推广应用 ,探讨了评价单元自动剖分、信息提取与存储、评价指标量化等矿井构造量化预测全程自动化实现技术的主要算法  相似文献   

煤矿区可持续发展中的环境问题与对策   总被引：10，自引：0，他引：10  

贾希荣  李林涛  宁建宏  顾广明  李云朝 《煤田地质与勘探》2001,29(1):39-42

煤炭作为一种不可再生资源，长期的开发活动已经引起了与我国国民经济可持续发展不协调的诸多环境问题，并且这些问题也已成为影响我国社会，经济和区域发展的综合性制约因素，因此有必要从煤矿区可持续发展角度，系统地认识和分析各环境霜素的制约与联系，采取系统性，持续性的环境保护对策，使煤矿区环境得到持续性改善。  相似文献