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41.
吕家金矿位于蓬(莱)-栖(霞)金成矿带中段,矿体受NNE向断裂控制,呈脉状、透镜状,矿石为黄铁矿石英脉及黄铁绢英岩。该矿床的形成主要受前寒武纪变质基底岩系、中生代岩浆岩以及复杂的构造体系等多种成矿因素叠加控制。寒武纪变质基底岩系、中生代岩浆岩在成矿作用过程中作为初始矿源层,为矿床成矿提供部分成矿物质来源,断裂构造则为含矿热液的迁移和富集沉淀提供良好通道和赋矿空间,岩浆活动是矿质运移的主要动力来源。通过对该矿床地质特征及矿床成因的总结研究,认为该矿床属岩浆中低温热液充填交代蚀变岩型金矿床。 相似文献
42.
中国红层的分布及地质环境特征 总被引:47,自引:3,他引:44
根据我国红层的分布特征及形成背景 ,将我国红层划分为西南地区红层、西北地区红层、中南、东南地区红层和其他地区 (西藏及华北的部分地区 )红层。重点研究了以川滇红层为代表的西南地区红层和以甘肃红层为代表的西北地区红层 ,研究了各个区域红层的地质构造特征、地形地貌特征、气候环境特征等工程地质环境特征 ,根据工程地质环境特征 ,将研究区域的红层划分为四川盆地红层、西昌滇中红层、滇西红层和甘肃红层. 相似文献
43.
In this study, four 1/5 scaled shaking table tests were conducted to investigate the seismic performance of recycled concrete frame-shear wall structures with different recycled aggregates replacement rates and concealed bracing detail. The four tested structures included one normal concrete model, one recycled coarse aggregate concrete model, and two recycled coarse and fi ne aggregate concrete models with or without concealed bracings inside the shear walls. The dynamic characteristics, dynamic response and failure mode of each model were compared and analyzed. Finite element models were also developed and nonlinear time-history response analysis was conducted. The test and analysis results show that the seismic performance of the recycled coarse aggregate concrete frame-shear wall structure is slightly worse than the normal concrete structure. The seismic resistance capacity of the recycled concrete frame-shear wall structure can be greatly improved by setting up concealed bracings inside the walls. With appropriate design, the recycled coarse aggregate concrete frame-shear wall structure and recycled concrete structure with concealed bracings inside the walls can be applied in buildings. 相似文献
44.
45.
Based on 10 shale samples collected from 4 wells in Qinshui Basin,we investigate the full-sized pore structure and fractal characteristics of Marine-Continental transitional shale by performing organic geochemistry,mineralogical composition,Nitrogen gas adsorption(N_2 adsorption)and Nuclear Magnetic Resonance(NMR)measurements and fractal analysis.Results show that the TOC content of the shale samples is relatively high,with an average value of 2.44wt%,and the thermal evolution is during the mature-over mature stage.The NMR T_2 spectrum can be used to characterize the fullsized pore structure characteristics of shale.By combining N_2 adsorption pore structure parameters and NMR T_2 spectrums,the surface relaxivity of samples are calculated to be between 1.7877 um/s and 5.2272 um/s.On this basis,the T_2 spectrums are converted to full-sized pore volume and surface area distribution curves.The statistics show that the pore volume is mainly provided by mesopore,followed by micropore,and the average percentages are 65.04%and 30.83%respectively;the surface area is mainly provided by micropore,followed by mesopore,and the average percentages are 60.8004%and39.137%respectively;macropore contributes little to pore volume and surface area.The pore structure characteristics of shale have no relationship with TOC,but strong relationships with clay minerals content.NMR fractal dimensions D_(micro) and D_(meso) have strong positive relationships with the N_2 adsorption fractal dimensions D_1 and D_2 respectively,indicating that D_(micro) can be used to characterize the fractal characteristics of pore surface,and D_(meso) can be used to characterize the fractal characteristics of pore structure.The shale surface relaxivity is controlled by multiple factors.The increasing of clay mineral content,pore surface area,pore surface fractal dimension and the decreasing of average pore size,will all lead to the decreasing of shale surface relaxivity. 相似文献
46.
扬子西缘广泛出露的新元古代澄江组是一套与晋宁运动密切相关的沉积岩夹火山岩系,其形成时限对华南新元古代区域地层格架、地层划分对比及古大陆再造具有重要意义。出露于滇中易门地区的新元古代澄江组底部发育有厚数米的凝灰岩夹层,本次采集凝灰岩进行LA-ICP-MS锆石U-Pb定年研究,结果表明,锆石206Pb/238U年龄加权平均值为812±5. 5Ma(n=17,MSWD=0.46),可以代表滇中澄江组的底界年龄,从而进一步确定澄江组底界年龄为812Ma左右。此外,凝灰岩中捕获的锆石年龄信息指示扬子西缘可能存在2. 5Ga、1. 8~1. 6Ga、1. 5Ga、1. 3Ga及1.0Ga等数期重要的区域构造-热事件。 相似文献
47.
双阳地区构造极为复杂,且有多期聚煤作用。上三叠统大酱缸组聚煤作用主要发生于古生界纬向断拗带之中,聚煤盆地类型以对冲断层谷式为主。下侏罗统太阳岭组聚煤作用是在纬向构造体系和新华夏构造体系的复合叠加环境下形成的,下白垩统的二道梁子组聚煤作用受控于双阳盆地轮廓的限制,两时期的聚煤盆地类型皆以开阔坳陷式为主。下白垩统的长岭组聚煤作用形成于金家屯组安山岩上的北东向断陷带之中,聚煤盆地类型以半地堑式为主。研究表明,双阳地区今后的找煤应突破双阳盆地周缘找煤的框架,物探、槽探相结合在南北向上寻找被第四系覆盖的大酱缸组煤系。 相似文献
48.
应用模糊评判法,在对延吉盆地石油地质基本特征分析的基础上,选取地质、物化探多年数,利用对各参数的权重分配进行调整,确定最佳分配方法,对盆地各区块大拉子组合油气性进行综合评判,其结果验证了目前钻井的情况,进而预测了下一步钻探的有利区块。 相似文献
49.
Wang Shaobin Song Wenzhi Su Weihan Zeng Jianghai Wang Zhiping Zhang Yuming 《大气科学进展》1995,12(1):114-120
N_2O emission from soil is affected by many factors. In this study, N_2O flux, soil temperature, water content, NO_3~- and NH_4~+ concentrations were simultaneously measured in winter wheat field. N_2O flux, NO_3~- and NH_4~+ concentrations were all lognormally distributed, while water content was normally distributed. The relationship between N_2O flux and soil factors was also studied. N_2O flux was most highly correlated with soil temperature. Regression model was developed to explain the variability of N_2O emission from agricultural soil using multifactorial analysis. 相似文献
50.
Control Factors of Solutional Voids in Feldspars and Favorable Zone Forecast of Chang 2 Oil Reservoir Group in the Midwest Ordos Basin
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GUO Shaobin ZHAO Pengda 《《地质学报》英文版》2007,81(5):798-804
The development of pores in a clastic reservoir is one of the most important research subjects in oil-gas exploration and development,whereas the many reasons for the formation of secondary porosity have increased the degree of difficulty in such research.Thus the research aims are to discover the controlling factors of solutional voids in feldspars and to predict favorable regions for these voids. Macroscopic and systematic researches into the relationship between the kaolinite content in the feldspar solutional void developed area of the Chang 2 reservoir group of the Triassic Yanchang Formation in the Midwest Ordos Basin and the solutional void in feldspar have been made,and from this it can be determined that the kaolinite content has an indicative function to the distribution of the solutional void in feldspar.Solutional void in feldspar is relatively well developed at the area where kaolinite content is high.Although the factors affecting kaolinite content are complicated,yet that of the research area is mainly affected by the impact of the leaching atmospheric water acting on the palaeogeomorphology.Three favorable zone belts for the development of solutional voids in feldspars are forecasted on the basis of restoration of palaeogeomorphology. 相似文献