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101.
通过牟定郝家河砂岩型铜矿床两类典型矿化的围岩蚀变类型、空间分布、蚀变矿物组合特征的综合分析,识别出该矿床存在成岩期与改造期两期热液蚀变。成岩期热液蚀变分布于浅紫交互带浅色砂岩一侧,呈现大范围面状硅化、碳酸盐化、黄铁矿化,并具蚀变分带:全浅色砂岩中的强硅化、黄铁矿化亚带;浅紫过渡砂岩中的强碳酸盐化、绢云母化、绿泥石化、弱硅化亚带,并具辉铜矿-斑铜矿-黄铜矿-黄铁矿的金属矿物分带。改造期热液蚀变主要分布于断裂、节理旁侧,表现为带状、网脉状的硅化、碳酸盐化。以1580 m中段实测剖面为研究对象,采集各蚀变亚带的代表样品,以紫色砂岩为原岩,进行主量元素、微量元素及稀土元素的组分迁入、迁出计算,结果显示各亚带组分的迁入、迁出特征与镜下观察的蚀变矿物组合吻合。分析表明,蚀变矿物组合与组分迁移特征还间接指示了不同亚带的形成条件:成岩期紫色砂岩(围岩)呈氧化-碱性条件,浅色砂岩呈还原-酸性条件,浅紫过渡矿化带则处于氧化还原-酸碱转化面上;改造期构造热液属还原-中偏碱性的中温构造流体。在此基础上,探讨了两期成矿流体分别形成层状矿体及脉状富矿体的机理,为深化研究该类矿床的"矿源-构造-流体耦合成矿"机制提供了重要证据。 相似文献
102.
MENG Dawei DING Xiaokun WU XiulingFaculty of Materials Science Chemical Engineering China University ofGeosciences Wuhan Hubei Testing Centre China University of Geosciences Wuhan Hubei 《《地质学报》英文版》2004,78(1):166-169
The process and path of retrometamorphism of coesite have great significance to our understanding of the P-T tracks of the exhumation of ultrahigh-pressure metamorphic rocks. Most of the coesites in the eclogite from Shima, Anhui Province, the Dabie Mountains, China, are found degraded to quartz partly or wholly, with ruptures occurring in the shells, outside which include the coesite and quartz. According to the microscopic observation, the sample of coesite inclusion is composed of garnet, quartz and coesite, based on which we have built a three-shelled composite sphere model to compute the transition of coesite. Based on the crystal growth formulas and pressure conditions of the ruptures in the garnet, we have calculated the radius of the quartz sphere, which depends on temperature, and eventually drawn the different retrometamorphic paths for different retrometamorphism rates. 相似文献
103.
SD法在湖北大冶鸡冠嘴铜金矿床资源储量核实中的应用 总被引:4,自引:0,他引:4
SD法是一种全新的储量计算和审定方法,是我国使用的三大储量计算方法(传统法、克里格法和SD法)之一.根据国土资源部的指示和要求,湖北三鑫金铜股份有限公司和北京恩地科技发展有限责任公司共同对矿区的13条勘探线、20个矿体、16个中段的资源储量运用SD法进行了全面的复核计算,成功地确定了鸡冠嘴铜金矿矿床-160~-170 m、-170~-470 m、-470 m以下铜和金的保有储量. 相似文献
104.
利用麦克斯韦方程组和边界条件,推导出由高低折射率介质组成周期性的多层增透膜系的传输矩阵,用传输性矩阵求出增透膜系的反射率和透射率表示式,采用Maple语言和数值计算方法得到4层和8层高反射膜系的反射率随入射光波长变化曲线,分析和讨论入射光的入射角对反射率和透射率的影响.得到的结果有利于对多层介质增透膜系结构的理解,为光学仪器镀膜的设计提供了理论依据. 相似文献
105.
The major elements, rare earth elements (REE) and trace elements of four basalt samples from central and western Pacific ferro- manganese crust provinces have been analyzed using chemical methods and ICP - MS, respectively. The results indicate that the samples have been extensively altered and that the contents of their major elements have changed significantly. However, the similarity of REE partition patterns and trace element contents of basalt samples to those of fresh oceanic island basalts (OIB) indicate that the basalt samples originated as OIB. Because of low-temperature alteration, the contents of A1203 , Fe203 , MnO, K20 and P205 increased, while MgO and FeO decreased. Active components, such as magnesium and iron, were leached from OIB resulting in the relative enrichment of SiO2. The leaching of active components can cause the relative enrichment of REE, while the precipitation of LREE-rich ferromanganese oxides in vesicles and fissures not only causes an increase of REE contents, but also induces "fractionation" of LREE and HREE. Based on the enrichment mechanism of REE contents, the theoretical quantities of precipitated ferromanganese oxides and the depleted quantities of active components are calculated : the depleted quantities of active components for the unit mass of fresh basalts vary in the range of 0.15 ~ 0. 657, and the precipitated quantities of ferromanganese oxides for the unit mass of fresh basahs vary in the range of 0. 006 ~ 0. 042. Of the major elements, the two most depleted are iron, and magnesium, with 18.28% ~ 70.95% of iron and 44.50% ~ 93.94% of magnesium in the fresh basalts was leached out. Theoretical calculation and geochemistry results both indicate that low-temperature alteration of basalts can supply abundant amount of metals to seawater, and may play an important role in ocean metal circulation. 相似文献
106.
The Luzon Strait is the only deep channel that connects the South China Sea(SCS) with the Pacific.The transport through the Luzon Strait is an important process influencing the circulation,heat and water budgets of the SCS.Early observations have suggested that water enters the SCS in winter but water inflow or outflow in summer is quite controversial.On the basis of hydrographic measurements from CTD along 120° E in the Luzon Strait during the period from September 18 to 20 in 2006,the characteristics of t... 相似文献
107.
108.
Influence of Structural Non-Stationarity of Surface Roughness on Morphological Characterization and Mechanical Deformation of Rock Joints 总被引:2,自引:2,他引:0
N. Fardin 《Rock Mechanics and Rock Engineering》2008,41(2):267-297
Summary Structural non-stationarity of surface roughness affects accurate morphological characterization as well as mechanical behaviour
of rock joints at the laboratory scale using samples with a size below the stationarity threshold. In this paper, the effect
of structural non-stationarity of surface roughness is investigated by studying the scale dependence of surface roughness
and mechanical behaviour of rock joints. The results show that the structural non-stationarity mainly affects the accurate
characterization of the surface roughness of the fracture samples. It also controls the amount and location of the contact
areas during shear tests, which in turn affects the mechanical properties and asperity degradation of the samples. It is concluded
that for accurate determination of the morphological and mechanical properties of rock joints at laboratory and field scales,
samples with size equal to or larger than the stationarity threshold are required.
Author’s address: Nader Fardin, Rock Mechanics Group, Department of Mining Engineering, Faculty of Engineering, University
of Tehran, P.O. Box: 11365/4563, Tehran, Iran 相似文献
109.
Wenjun Yong E. Dachs A. C. Withers E. J. Essene 《Contributions to Mineralogy and Petrology》2008,155(2):137-146
The low-temperature heat capacity (C
p) of Si-wadeite (K2Si4O9) synthesized with a piston cylinder device was measured over the range of 5–303 K using the heat capacity option of a physical
properties measurement system. The entropy of Si-wadeite at standard temperature and pressure calculated from the measured
heat capacity data is 253.8 ± 0.6 J mol−1 K−1, which is considerably larger than some of the previous estimated values. The calculated phase transition boundaries in the
system K2O–Al2O3–SiO2 are generally consistent with previous experimental results. Together with our calculated phase boundaries, seven multi-anvil
experiments at 1,400 K and 6.0–7.7 GPa suggest that no equilibrium stability field of kalsilite + coesite intervenes between
the stability field of sanidine and that of coesite + kyanite + Si-wadeite, in contrast to previous predictions. First-order
approximations were undertaken to calculate the phase diagram in the system K2Si4O9 at lower pressure and temperature. Large discrepancies were shown between the calculated diagram compared with previously
published versions, suggesting that further experimental or/and calorimetric work is needed to better constrain the low-pressure
phase relations of the K2Si4O9 polymorphs.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
110.
雷电灾害风险评估中,雷击风险的计算方法有人工计算、Excel表格计算和软件计算3种。选取石嘴山一油库为案例,依据风险管理标准(GB/T 21714.2 -2015),分别采用人工、Excel和软件方法,计算该油库雷电风险总量和风险分量。计算结果显示,软件计算风险总值相对人工计算值总是偏高,特别是对于易燃易爆场所,比人工计算、Excel计算值高20~30倍;人工方法、Excel方法风险总值计算结果较为一致。造成差别的原因是,人工计算主观性大,不同的评估人员在风险分量的选取及计算过程中会出现较大的差别,容易忽略部分风险分量,从而造成风险总量的减少。在风险分量的组成上,对第三类防雷建筑物,人工计算结果更符合实际;对第一、二类防雷建筑物,软件计算结果更符合实际。 相似文献