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41.
岩体通常是以孔隙岩石为基质并包含各种成因的裂隙和溶隙的复杂多空隙组合地质材料。为研究孔隙-裂隙-溶隙多空隙组合介质的渗流特性,在简要介绍多孔介质渗流Darcy定律、平板窄缝流Poiseuille定律和圆形管道流Darcy-Weibach理论的基础上,分析了几种孔隙-裂隙-溶隙组合情况的多空隙介质渗流特性,推导出相应组合的等效渗透系数KE,给出了描述多空隙组合介质KE的一般表达式,讨论了影响各种空隙组合KE的主要因素。以普通砖模拟岩石基质,通过砖身钻孔填充及砖间缝隙填充,试验模拟了岩溶岩体和裂隙岩体中溶孔和裂隙填充后的渗透情况。试验结果与所推求理论公式计算出的KE在同一量级且误差很小,很好地验证了所推导的多空隙组合介质渗透系数表达式的有效性。 相似文献
42.
董振信 《中国地球化学学报》1998,17(1):29-43
Based on the measurements of refractive index,specific gravity,unit cell parameter,and mineral chemistry and infrared absorption spectrum analyses of pyropes in kimberlites from China,systematic studies of the Physical properties and compositional variations of pyropes of different colors and diverse paragenetic types,within and between kimberlite provinces have been undertaken,The origin of pyropes in the Kimberlites and the depth of their formation have been discussed.Pyropes of the purple series are different from those of the orange series in physical and chemical properties,for exaple,pyropes of the puple series are higher in α0,RI,SG,Cr2O3,MgO,Cr/(Cr Al),Mg/(Mg Fe),and Mg/(Mg Ca),and lower in Al2O3,Fe2O3 FeO than those of the orange series.The classification of garnets in kimberlites from china by the Dawson and Stephens‘ method(1975) has been undertaken and clearly demonstrates that pyropes of diamond-rich kimberlites contain much more groups than those of diamond-poor,especially diamond-free kimberlites.The higher in α0,RI,SG,Cr2O(3.Cr/(Cr Al),knorringite and Cr-component the pyropes are ,the richer in diamond the kimberlites will be.The infrared absorption spectrum patterns of pyropes change with their chemical composition regularly,as reflected in the shape and position of infrared absorption peaks.Two absortpion bands at 862-901 cm^-1 will grade into degeneration from splitting and the absorption band positions of pyropes shift toward lower frequency with increasing Cr2O3 content and Cr/(Cr Al) ratio of pyropes,LREE contents of orange pyrope megacrysts are similar to those of porple pyrope macrocrysts,but the former is higher in HREE than the latter,showing their different chondrite-normalized patterns.The formation pressures of pyropes calculated by Cr-component,Ca-component,knorringite molecules of pyropes show that some pyropes of the purple series in diamondiferous kimberlites fall into the diamond stability field.but all pyropes of diamond-free kimberlites lie outside the diamond stability field.The megacrysts were formed through early crystallization of kimberlites magma at high pressure condition,the majority of the purple pyrope macrocrysts have been derived from disaggregated xenoliths but the minoirty of them appear to be fragments of the discrete megacryst pyropes,or phenocrysts. 相似文献
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豫西南蒲塘金矿床地质特征及成因探讨 总被引:4,自引:0,他引:4
蒲塘金矿床属爆破角砾岩型,主成矿期温度236~318℃,主矿体受爆破角砾岩筒控制,含矿围岩蚀变及矿体变化规律明显,黄铁矿及黄铜矿是金的主要载体矿物。矿石中Au-Cu含量呈正消长关系,成矿物质主要来源于花岗岩,从花岗岩的侵入到矿床的形成,大体上经过了晚燕山期浅成初始岩浆侵入-爆破,超浅成强烈爆破及热液成矿三个阶段。 相似文献
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以T42产品为因子用卡尔曼滤波方法作温度预报 总被引:3,自引:4,他引:3
本文以T42数据预报产品为因子,用卡尔曼滤波方法建立可更新系数的预报方程作南京和芜湖的温度预报。从1994年1月至4月共84次试报中,用完全相同的因子卡尔曼滤波方法比回归分析方法预报结果精度提高0.5度。 相似文献
49.
A new two-way land-atmosphere interaction model (R42_AVIM) is fulfilled by coupling the spectral at- mospheric model (SAMIL_R42L9) developed at the State Key Laboratory of Numerical Modeling for Atmo- spheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sci- ences (LASG/IAP/CAS) with the land surface model, Atmosphere-Vegetation-Interaction-Model (AVIM). In this coupled model, physical and biological components of AVIM are both included. Climate base state and land surface physical fluxes simulated by R42_AVIM are analyzed and compared with the results of R42_SSIB [which is coupled by SAMIL_R42L9 and Simplified Simple Biosphere (SSIB) models]. The results show the performance of the new model is closer to the observations. It can basically guarantee that the land surface energy budget is balanced, and can simulate June-July-August (JJA) and December-January- February (DJF) land surface air temperature, sensible heat flux, latent heat flux, precipitation, sea level pressure and other variables reasonably well. Compared with R42_SSIB, there are obvious improvements in the JJA simulations of surface air temperature and surface fluxes. Thus, this land-atmosphere coupled model will offer a good experiment platform for land-atmosphere interaction research. 相似文献
50.
Discovery of diamondiferous kimberlites in the Mainpur Kimberlite Field, Raipur District, Chhattisgarh in central India, encouraged investigation of similar bodies in other parts of the Bastar craton. The earlier known Tokapal ultramafic intrusive body, located beyond the 19-km milestone in Tokapal village along the Jagdalpur–Geedam road, was reinterpreted as crater-facies kimberlite. Its stratigraphic position in the Meso-Neoproterozoic intracratonic sedimentary Indravati basin makes it one of the oldest preserved crater-facies kimberlite systems. Ground and limited subsurface data (dug-, tube-wells and exploratory boreholes) have outlined an extensive surface area (>550 ha) of the kimberlite. The morphological and surface color features of this body on enhanced satellite images suggest that there is a central feeder surrounded by a collar and wide pyroclastic apron. Exploration drilling indicates that the central zone probably corresponds to a vent overlain by resedimented volcaniclastic (epiclastic) rocks that are surrounded by a 2-km-wide spread of pyroclastic rocks (lapilli tuff, tuff/ash beds and volcaniclastic breccia). Drill-holes also reveal that kimberlitic lapilli tuffs and tuffs are sandwiched between the Kanger and Jagdalpur Formations and also form sills within the sedimentary sequence of the Indravati basin. The lapilli tuffs are commonly well stratified and display slumping. Base surges and lava flows occur in the southern part of the Tokapal system. The geochemistry and petrology of the rock correspond to average Group I kimberlite with a moderate degree of contamination. However, the exposed rock is intensely weathered and altered with strong leaching of mobile elements (Ba, Rb, Sr). Layers of vesicular fine-grained glassy material represent kimberlitic lava flows. Tuffs containing juvenile lapilli with pseudomorphed olivine macrocrysts are set in a talc–serpentine–carbonate matrix with locally abundant spinel and sphene. Garnet has not been observed, and phlogopite is very rare. Very limited microdiamond testing (two 18-kg samples) proved negative; however, the composition of chromite grains indicate crystallization in the diamond stability field. 相似文献