煤田资料的铀矿二次开发技术及其找矿意义——以二连盆地ZS煤田铀矿点的发现为例   总被引：2，自引：1，他引：1       下载免费PDF全文

吴兆剑  韩效忠 《中国地质》2016,(2):617-627

在中国北方主要盆地铀矿地质调查工作中,煤田自然伽马异常作为主要矿化信息和找矿线索,为一系列铀矿床(点)的快速发现奠定了坚实基础。为进一步提高煤田资料铀矿二次开发的高效性和准确性,运用水成铀矿理论,以中国二连盆地ZS煤矿区典型铀矿点的发现为例,初步探讨了煤田资料的铀矿二次开发技术,提出了"异常筛选与选区分析、原位验证与环境判别、等时地层格架建立与沉积体系分析、综合分析与靶区定位"四位一体的煤矿区铀矿地质调查模式。这对中国北方含煤盆地铀矿地质调查工作提供了新的找矿思路和技术路线,具有较重要的指导意义。  相似文献   

Coal-measure source rock characteristics and burial evolution history in the Shisanjianfang Area,Tuha Basin     

Zhiyuan Wu  Suping Peng  Wenfeng Du 《Arabian Journal of Geosciences》2016,9(5):417

Shisanjianfang Area in the eastern margin of Taibei Sag, Tuha Basin, is an important region for oil and gas exploration. In this study, a large number of source rock geochemical data were used to analyze the geochemical characteristics of coal-measure source rocks in the Shisanjianfang Area, Tuha Basin, from three aspects, i.e., organic matter abundance, organic matter type, and organic maturity. The results show that the Jurassic Xishanyao Formation (J₂x) in the study area has great thickness, continuous distribution, and high source rock maturity, and is the major source rock horizon in the study area. The seismic data are used in combination with 1D and 2D basin simulation technology to study the distribution characteristics of the source rocks in Shisanjianfang Area. The results of the simulation research on the source rock maturity history in the study area indicate the following: (1) The source rocks in the Xishanyao Formation (J₂x) have a hydrocarbon generation threshold depth of 1800 m, threshold temperature of 95 °C, and hydrocarbon generation threshold time of about 162 Ma. (2) The Xishanyao Formation (J₂x) has a current formation temperature of 50~110 °C and Ro of 0.6~1.1 % in the peak oil generation stage. (3) The source rock maturity in the study area is shown as being higher in the west while lower in the east, and higher in the north while lower in the south, and the favorable exploration area mainly lies in the northwest of the study area. The results of this study could have important implications for the oil and gas exploration in the margins of Xiaocaohu Sag, Tuha Basin.  相似文献   

Mechanical characteristics of dip basement effects on dump stability in the Shengli open pit mine in Inner Mongolia,China     

Liu Han  Jisen Shu  Qingxiang Cai  Hongwen Jing  Hua Tian 《Arabian Journal of Geosciences》2016,9(20):750

For waste dump slopes that form basements, landslides can be prevented by determining a stability evolving law of dynamic development. Keeping this issue in mind, the relationship between the mechanical structure and stability of waste dumps with basements is studied. Three key factors that influence waste dump stability are presented, and judgment criteria for self-locking and unlocking states of dump basements are provided. From the friction coefficient of waste dump basement stability analyses of the Shengli open pit mine, the results indicate that waste dump basements on the right side of fault F8 and on the left side of fault F61 are subjected to self-locking. However, between faults F61 and F8, the basement is subjected to unlocking. Regarding the residual thrusting of unlocking areas, structure and stability optimization schemes for waste dumps in the Shengli open pit mine are provided through a mechanics analysis. Reducing the slopes and basement angles of waste dumps can enhance their stability by increasing basement roughness levels.  相似文献   

A novel method to estimate mineral compositions of mudrocks: A case study for the Canadian unconventional petroleum systems     

《Marine and Petroleum Geology》2016

The mineral composition of mudrocks is an essential attribute in controlling the reservoir quality of unconventional petroleum systems. The present study introduces a semi-quantitative method to estimate mineral phases of mudrocks in various Canadian unconventional hydrocarbon systems using total elemental analysis (inductively coupled plasma-mass spectrometry (ICP-MS)) and Rock-Eval data (total organic carbon (TOC) and mineral carbon (MinC)).This method involves statistical analysis based on a sound knowledge of hydrocarbon source rock inorganic geochemistry. The workflow can be divided into four steps: (i) converting major elements (Si, Al, Fe, K, Na, Ca, Mg, Ti, and P) to their oxides, (ii) inferring modes of occurrence of elements using statistical analysis of geochemical data (major elements, TOC, and MinC), (iii) identifying the mineral types (oxide, aluminosilicates, carbonates, sulfide, and phosphate) according to elemental occurrences and calculating mineral phase concentrations, and (iv) verifying the results by comparing to XRD data on selected samples. The results, especially for brittle minerals such as quartz, carbonates (e.g. calcite, dolomite, and ankerite), and pyrite, show that the estimated mineral compositions correspond closely and consistently with measured mineralogy obtained from XRD. This method takes advantage of bulk geochemical data already available for hydrocarbon potential and chemostratigraphic studies, without devoting additional samples and cost for XRD analysis.  相似文献   

Study of Influence of Regional Geodynamic Background on Strata Behaviors in China's Tongxin Mine          下载免费PDF全文

Ying Chen  Hongwei Zhang  Bin Yu  Zhijie Zhu  Wenda Wu  Yunpeng Li 《Resource Geology》2016,66(1):1-11

Strata behaviors are mainly affected by regional geodynamic background. The influence of rock mass stress and energy distribution on strata behaviors in the Tongxin mine is studied in terms of regional tectonic movement, seismic activity and tectonic stress field. The results show that the extrusion lifting movement of Kouquan fault adjacent to the Tongxin mine results in the stress concentration in the rock of the Carboniferous coal bed and accumulation of a large amount of elastic energy and forms structural background of Tongxin mine. Due to various seismic activities in the mine area, the strain energy is known to reach much higher levels, up to 0.5×10⁸ J^1/2. Since the stratigraphic structure is sensitive to the mining operation, the strain energy could cause strong strata behaviors. A special geological structure model of the Tongxin mine is established based on the geodynamic division method. The distribution of regional structure stress field is determined by the rock mass stress analysis system. Based on this model, Tongxin mine is divided into five areas with high stress, eight areas with low stress and eight areas with gradient stress. The strong strata behaviors mostly occur in high stress areas. These results could provide guidance to predict the strength of regional or mine pressure and control strata behavior in different areas.  相似文献   

Geochemistry,petrogenesis and tectonic setting of Neoproterozoic mafic–ultramafic rocks from the western Jiangnan orogen,South China     

《Gondwana Research》2016

The Jiangnan orogenic belt (JOB) has been interpreted as a suture zone between the Yangtze craton and Cathaysian terranes in South China. The Neoproterozoic mafic–ultramafic rocks are extensively exposed in the western JOB, providing an ideal opportunity to study the Neoproterozoic assembly and tectonic evolution of South China. We present integrated field and geochemical studies including LA-ICP-MS zircon U–Pb dating, and whole-rock major and trace element and Sm–Nd isotope analyses of the Neoproterozoic mafic–ultramafic rocks exposed in the northern Guangxi Province, South China. Geochronological results show that the magmatic events took place in two distinct periods: the early Neoproterozoic (861–834 Ma) and the late Neoproterozoic (770–750 Ma). Early Neoproterozoic ultramafic rocks of the Sibao Group have positive ε_Nd(t) values (+ 2.7 to + 6.6) whereas mafic rocks exhibit negative ε_Nd(t) values (− 5.8 to − 0.9). The basaltic rocks show TiO₂ contents of 0.62–0.69 wt.% and Mg-number of 59–65, and also display an enrichment of light rare earth elements (LREEs) and pronounced negative Nb, Ta and Ti anomalies on chondrite- and primitive mantle-normalized diagrams, consistent with subduction-related geochemical signatures. Late Neoproterozoic rocks of the Danzhou Group show ε_Nd(t) values (− 1.23 to + 3.19) for both ultramafic and mafic rocks. The basaltic rocks have TiO₂ contents of 1.01–1.33 wt.% and Mg-number of 57–60, and have a mixture of MORB- and arc-like geochemical affinities, inferred to have formed in an extensional arc environment. Geochemical signatures suggest that all rock types in this study were derived from subarc mantle wedge sources and underwent various degrees of crustal contamination. Thus, we suggest that subduction may have continued to ca. 750 Ma in the western JOB, implying that the amalgamation event between the Yangtze craton and Cathaysian terranes was later than 750 Ma.  相似文献   

Middle Permian U–Pb zircon ages of the “glacial” deposits of the Atkan Formation,Ayan-Yuryakh anticlinorium,Magadan province,NE Russia: Their significance for global climatic interpretations     

《Gondwana Research》2016

The Atkan Formation in the Ayan-Yuryakh anticlinorium, Magadan province, northeastern Russia, is of great interest because of the occurrence of deposits of apparent “dropstones” and “ice rafted debris” that have been previously interpreted as glacial. Two high-precision U–Pb zircon ages, one for an intercalated volcanic tuff (262.5 ± 0.2 Ma) and the other for a boulder clast (269.8 ± 0.1 Ma) within a diamictite of the Atkan Formation, constrain the age of the Atkan Formation as Guadalupian (middle Permian). Sedimentologic study of the Atkan Formation casts doubt on the glacial nature of the diamictites. Deposition of rocks of the Atkan Formation temporally correlates with the Capitanian interglacial event in the southern hemisphere that recently was calibrated with high precision CA-TIMS. The previously proposed climate proxy record based upon warm-water foraminifera, which corresponds closely to global climate fluctuations, is compared with the glacial record of eastern Australia and indicates that the Capitanian was a time of globally warm climate. The sedimentology of Atkan Formation, the record of diversification of both fusulinids and rugosa corals, global sea-water temperature, and sea-level fluctuations agree well with high latitude paleoclimate records in northeastern Russia and eastern Australia. Major components of the Atkan Formation, the volcanic rocks, are syngenetic with the sedimentation process. The volcanic activity in the nearby regions during middle–late Permian was quite extensive.  相似文献   

莺琼盆地中新统海相烃源岩地球化学特征及生烃潜力评价     

王元  李贤庆  王刚  徐新德  刘海钰 《现代地质》2018,32(3):500

通过有机碳测定、岩石热解分析、显微组分定量分析、饱和烃色谱、色谱-质谱等实验分析,对莺琼盆地中新统海相烃源岩的地球化学特征进行了研究,探讨了不同层位烃源岩的生烃潜力。结果表明：莺琼盆地中新统海相烃源岩有机质丰度总体较低,大部分烃源岩为中等烃源岩,有机质类型以Ⅱ2型和Ⅲ型为主,有机质热演化主要处于成熟阶段。烃源岩显微组分组成具有富含镜质组、壳质组+腐泥组次之、贫含惰性组的特征。烃源岩沉积环境主要为弱氧化-弱还原环境,具有陆生高等植物和低等水生生物生源混合输入的特征。莺歌海盆地梅山组烃源岩综合评价为中等烃源岩,生烃潜力相对较好,三亚组烃源岩综合评价为较差—中等烃源岩,具有一定的生烃潜力。琼东南盆地梅山组和三亚组烃源岩综合评价为中等烃源岩,具有相当的生烃潜力。  相似文献   

Dual Control of Depositional Facies on Uranium Mineralization in Coal‐bearing Series: Examples from the Tuanyushan Area of the Northern Qaidam Basin,NW China     

GUO Biao  SHAO Longyi  WEN Huaijun  HUANG Guangnan  ZOU Mingjun  LI Yonghong 《《地质学报》英文版》2018,92(2):733-754

The uranium deposits in the Tuanyushan area of northern Qaidam Basin commonly occur in coal-bearing series. To decipher the U-enrichment mechanism and controlling factors in this area, a database of 72 drill cores, including 56 well-logs and 3 sampling wells, was examined for sedimentology and geochemistry in relation to uranium concentrations. The results show that coal-bearing series can influence uranium mineralization from two aspects, i.e., spatial distribution and dynamic control. Five types of uranium-bearing rocks are recognized, mainly occurring in the braided river and braided delta sedimentary facies, among which sandstones near the coals are the most important. The lithological associations of sandstone-type uranium deposits can be classified into three subtypes, termed as U-coal type, coal-U-coal type, and coal-U type, respectively. The coal and fine siliciclastic rocks in the coalbearing series confined the U-rich fluid flow and uranium accumulation in the sandstone near them. Thus, the coal-bearing series can provide good accommodations for uranium mineralization. Coals and organic matters in the coal-bearing series may have served as reducing agents and absorbing barriers. Methane is deemed to be the main acidolysis hydrocarbon in the U-bearing beds, which shows a positive correlation with U-content in the sandstones in the coal-bearing series. Additionally, the δ13 C in the carbonate cements of the U-bearing sandstones indicates that the organic matters, associated with the coal around the sandstones, were involved in the carbonation, one important component of alteration in the Tuanyushan area. Recognition of the dual control of coal-bearing series on the uranium mineralization is significant for the development of coal circular economy, environmental protection during coal utilization and the security of national rare metal resources.  相似文献   

PNN在煤田随钻测井岩性判识应用研究     

陈刚 《地质与资源》2018,27(1):103-106

介绍了PNN方法原理及其算法训练学习过程,详细阐述了网络识别岩性参数的选取、岩性识别模型的建立过程.通过对比研究PNN与其他6种岩性识别方法,分析相同条件下预测结果,得到不同识别方法的优劣性.经研究发现,PNN概率神经网络方法在生产应用中效果更佳、训练识别用时最短.利用人工智能神经网络对测井数据进行自动解释分析,可满足随钻测井时效性及快速解释处理的地质导向需求.  相似文献