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91.
Sen Zhang Nan Ju Guo-bin Zhang Yuan-dong Zhao Yun-sheng Ren Bao-shan Liu Hui Wang Rong-rong Guo Qun Yang Zhen-ming Sun Feng-ming Xu Ke-yong Wang Yu-jie Hao 《China Geology》2023,6(1):100-136
The reserves of the Duobaoshan porphyry Cu-Au-Mo-Ag deposit(also referred to as the Duobaoshan porphyry Cu deposit) ranks first among the copper deposits in China and 33rd among the porphyry copper deposits in the world. It has proven resources of copper(Cu), molybdenum(Mo), gold(Au), and silver(Ag) of 2.28×106 t, 80×103 t, 73 t, and 1046 t, respectively. The major characteristics of the Duobaoshan porphyry Cu deposit are as follows. It is located in a zone sandwiched by th... 相似文献
92.
工业界计算孔隙压力系数普遍应用的Eaton和Fillippone方法都需要构建能够准确表征低速层的层速度模型,层速度模型精度及效率成为制约孔隙压力预测的关键参数,但目前工业界层速度建模的精度及效率很难满足孔隙压力预测的要求.本文由正常压实情况下的背景速度场出发,基于时距曲线公式及角道集抽取公式,创新推导了以角度域共成像点道集(ADCIGS)剩余曲率为自变量的孔隙压力系数计算公式,该公式完全由去噪后的地震数据进行驱动,不需要构建层速度模型,该方法大幅提高了计算孔隙压力系数的效率.由模型测试及实际数据应用证明,利用本文提出方法进行孔隙压力预测是有效可行的,该方法可以有效提高预测孔隙压力精度,还可以有效提高预测孔隙压力效率. 相似文献
93.
中亚成矿域斑岩铜矿床基本特征 总被引:9,自引:2,他引:7
中亚成矿域发育许多大型和超大型斑岩铜矿床,是世界上重要的斑岩铜矿成矿域。我们对9个大型和超大型斑岩铜矿床进行了研究,包括地质特征、含矿岩体地球化学、SIMS锆石U-Pb定年和成矿流体成分等,结合前人成果,我们认为中亚成矿域斑岩铜矿床具有如下特点:(1)成矿时代为古生代和中生代,成矿高峰期为泥盆纪和石炭纪;(2)含矿岩浆为钙碱性中酸性岩浆和少量的碱性岩浆,含矿岩体为花岗闪长岩、闪长岩、英云闪长岩和少量的二长岩;(3)含矿岩浆大多数源于新生的洋壳,少量有古老的基底物质和围岩物质参与;(4)成矿构造背景主要为岛弧,少量为陆缘弧和岛弧向陆缘弧过渡的环境;(5)矿床可分为三类,包括斑岩型Cu-Au、Cu(Au,Mo)和Cu-Mo矿床;(6)成矿流体可分为两类,包括氧化性H2O-Na Cl-CO2-SO2体系和少量的还原性H2O-Na Cl-CH4-CO2体系;(7)成矿系统可分为三类,包括简单的斑岩系统和少量的斑岩-矽卡岩成矿系统和斑岩-浅成低温热液成矿系统。 相似文献
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96.
介绍一种基于时域脉冲反射(TDR)的多芯电缆故障测试装置.使用C8051F005单片机为处理核心,控制CPLD向电缆注入脉冲信号,通过双机联测的方式在电缆两端点同时进行测量,可快速判断电缆短接,混接以及芯线断线等故障以及故障点的位置,故障位置定点可精确到5 m以内,该装置设计成本低廉,操作方便,具有良好的应用前景. 相似文献
97.
An analytic solution based on the division of the fluid domain is developed for the interaction of obliquely incident waves with infinite number of perforated caissons. The whole fluid domain is firstly divided into infinite sub-domains according to the division of structures, and subsequently eigenfunction expansion is employed to represent the velocity potential in each domain. A phase relation is utilized for the analysis of wave oscillation in each caisson, and the character of structure geometry is considered in setting up the mathematical model of reflection waves. The reflection waves from the present analysis include many propagation waves traveling in different directions when the incident wave frequency is high. Benchmark examinations show that the continuous condition of water particle velocity is satisfied at the front walls of caissons, and the reflection coefficients keep agreement with the energy conservation relation very well when porous effect parameter is infinite. Numerical results show that the reflection coefficients of obliquely incident waves are smaller when the length of caissons is shorter at low frequency. The wave reflection coefficients and the wave forces normal to caissons decrease and the wave forces along caissons increase with the increase of the wave incident angle. 相似文献
98.
《International Geology Review》2012,54(4):481-500
Major- and trace-element and U–Pb analyses of detrital zircons were performed on metavolcano sedimentary sequences and igneous rocks from the Ceará Central Domain (CCD) in the Borborema Province of northeastern Brazil. No significant geochemical differences were found between these rocks, which were possibly initially deposited as parts of a very large metavolcano-sedimentary sequence. Weathering in the source area was moderate, and the sediments were deposited as both sands and clays. The sources of the sediments were likely mixtures of felsic and intermediate rocks deposited predominantly in an active-margin setting with minor contributions of both continental arc and passive margin components. Three main source ages were identified: Palaeoproterozoic (~2.2 Ga), for which potential sources include the Palaeoproterozoic Madalena-Algodões Suite; early Neoproterozoic (~850 Ma), related to felsic volcanic magmatism due to continental rifting, initial phases of the Santa Quitéria Magmatic Arc, or magmatic arc systems on the margins of the Palaeoproterozoic crust; and late Neoproterozoic (~650 Ma), associated with extensive granite generation and migmatization events accompanying Santa Quitéria Arc activity. Deposition of the CCD volcanosedimentary rocks occurred shortly before regional, collision-type metamorphism accompanying the amalgamation of the São Francisco-Congo Cratons (~ 620–630 Ma). 相似文献
99.
Data from agglutinated benthic foraminiferal assemblages and geochemical proxies make it possible to characterise different order sea-level dynamics —from a geological scale third-order transgressive-regressive cycle to a minor-scale, ecological range, maximum flooding-initial regressive phase—in part of the Valanginian from Spitsbergen. The transgressive-regressive cycle starts with abundance (foram/100 g) of opportunist epifaunal forms related to deep waters and low productivity conditions on oxygenated sea-bed. The increase of these foraminifera, together with increased condensation and an impoverishment of trophic resources, is associated with the maximum flooding phase. The beginning of the subsequent regression shows a progressive diminution in foraminiferal abundance as a result of the greater sedimentation rate, the mounting proportions of deep infaunal forms, and the diminution of genera of deep-water environments. This initial regressive phase is associated with more arid climatic conditions (abrupt increase of eolian detrital proxies), and high palaeoproductivity (increase of Ba/Al, Sr/Al and P/Ti ratios and TOC), determining a diminution in the oxygenation (high values in Co/Al, Ni/Al and Mo/Al ratios and hydrogen index). After the initial productivity bloom, the foraminiferal abundance decreases, whereas diversity increases, favoured by the stability of environmental conditions (no fluctuations in palaeoproductivity, detrital and redox proxies), in turn related to deceleration of sea-level fall. The peaks of maximum foraminiferal abundance (optimum) of each morphogroup during the transition from maximum flooding to the beginning of regression allow us to identify an ecological replacement inter- and intra-microhabitats. In the different phases of ecological replacement, the dominant morphogroups are distributed in distinct microhabitats (epifaunal, shallow infaunal and deep infaunal) as a result of competition. 相似文献
100.
It is generally acknowledged that immovable property taxes are one of the main revenue sources for local government. The literature emphasizes that the administration of property taxes needs well-developed inventories or registers that provide complete and accurate records of the taxed properties and their legal-economic attributes. This requirement is generally fulfilled by Spatial Data Infrastructures (SDIs) in which the coordinate exchange and sharing of geo-spatial data is provided by separate registers/information systems such as: cadastral systems, building and address registers. Recently, the Open Geospatial Consortium presented a core component of a 3D SDI in the form of an international domain standard for representing, storing and exchanging 3D city models. The CityGML allows the semantic and 3D geometrical representation of physical objects but does not deal with the legal and administrative aspects of the city objects which are required for the process of property taxation. This paper outlines the development of an Application Domain Extension (ADE) for the immovable property taxation domain that expands the CityGML data model with the legal and administrative concepts defined in Turkish Law. The study shows that this ADE could be a 3D national data model for municipal information systems and facilitate a more efficient taxation process, as well as providing data for urban planning, facility management and other municipal services. 相似文献