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61.
把无粘流中能成功捕捉接触间断的反扩散差分格式,用在了准地转二维理想锋生的数值模拟中,并将计算结果与Cullen的计算结果和半地转方程的精确解进行了比较。用反扩散格式模拟的锋面较Cullen的结果更加显,而且更接近半地转方程的精确解。 相似文献
62.
江西银山多金属矿床伊利石的形成与流体成矿作用的初步研究 总被引:4,自引:0,他引:4
江西银山多金属矿床的热液蚀变粘土矿物主要由伊利石组成,伊利石主要由流体作用过程中长石的伊利石化形成,其结晶度与成矿流体作用密切相关.银山第1期铅锌银成矿作用,水/岩比相对较低,成矿流体以孔隙渗透为主,溶质迁移慢,形成含有少量膨胀层的伊利石;第2期铜金成矿作用,水/岩比相对较高,流体的运移方式以通道式或裂隙式为主,溶质迁移的速度快,形成不含膨胀层的伊利石.研究表明成矿作用过程中的伊利石化主要与铅锌银矿化有关,而绿泥石化与铜金矿化有关. 相似文献
63.
64.
长江三峡工程正常蓄水位为175m,在蓄水过程中随着库水位的抬升,必然会引起库岸边坡地下水渗流场的变化。运用3D-Modflow软件模拟了三峡工程的蓄水过程中奉节库段边坡岩土体内部地下水位的动态变化,为长江三峡工程奉节库区段移民迁建地质灾害预测与防治提供科学依据。 相似文献
65.
The chronological data obtained by a variety of dating methods have confirmed that the sodium enriched metavolcanite series
in the area of the Longbohe copper deposit at Jinping, Yunnan Province, was formed during the Proterozoic (its Pb−Pb isochron
age=1595±75 Ma), corresponding to the Dahongshan Group sodium enriched metavolcanites. The Sm−Nd isochron age of 1336±46Ma
should represent the time at which this series of volcanic rocks experienced spilitization in response to sodium metasomatism,
equivalent to the time of sedimentation of the Ailaoshan Group and Yashan Group rocks. The Rb−Sr ages of the volcanic rocks
and the Pb−Pb ages of copper ores have recorded the events of strong dynamic metamorphism and of strong reworking-metallogenesis
of copper during the Jinningian period. Similarities in forming age, rock assemblage and isotopic characteristics between
the sodium enriched metavolcanite series and the Dahongshan Group sodium enriched metavolcanite series have provided new clues
to the exploration of the Dahongshan-type copper deposits in this area.
Granted jointly by the National Natural Science Foundation of China (Nos. 49702022, 40073001) and the State 973 Program (No.
G1999043215). 相似文献
66.
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68.
Mt. Qomolangma lies in the collision zone between the fringe of Eurasia plate and Indian plate. The crustal movement there
is still very active so far. In the past three decades China carried out five geodetic campaigns in Mt. Qomolangma and its
north vicinal area, independently or cooperatively with other countries, including triangulation, leveling, GPS positioning,
atmospheric, astronomical and gravity measurements. On the basis of the observation results achieved in the campaigns the
crustal movements in the area were studied and explored. A non-stationary phenomenon both in time and space of the crustal
vertical movement in the area is found. There seems to be some relevance between the phenomenon of non-stationary in time
and seismic episode in China. The phenomenon of non-stationary in space is possibly relevant to the no-homo- geneity of crustal
medium and non-uniform absorption of terrestrial stress. The horizontal crustal movement in the area is in the direction of
NEE at a speed of 6–7 cm per year, and the trend of strike slip movement is manifested evidently in the collision fringe of
Indian plate and Qinghai-Xizang block. 相似文献
69.
Quantitative reconstruction of the lake water paleotemperature of Daihai Lake, Inner Mongolia, China and its significance in paleoclimate 总被引:5,自引:2,他引:5
By measuring Sr/Ca ratios of the ostracod shells (Limnocthere cf. inopinata) in sediments of the Daihai Lake, and combined with Sr2+/Ca2+ ratios of the lake water, this paper obtained paleosalinity of the lake water. Vaporizing experiment of the lake water in
laboratory showed that there was a quantitative relationship between salinity and oxygen isotope. Using this relationship,
oxygen isotope values of the paleo-lake water were calculated. By measuring the oxygen isotope of the authigenic carbonate
in the lake’s sediments, and in combination with the oxygen isotope values of the paleo-lake water, the paleotemperature of
the lake water was calculated. Finally, based on these proxies, the paleoclimate in the lake basin was explored. 相似文献
70.
Yves Moëlo Pierre Palvadeau Nicolas Meisser Alain Meerschaut 《Comptes Rendus Geoscience》2002,334(8):529-536
Cu-poor meneghinite from La Lauzière Massif (Savoy, France) has the composition (electron microprobe) (in wt%): Pb 59.50, Sb 20.33, Bi 1.19, Cu 0.87, Ag 0.05, Fe 0.03, S 17.62, Se 0.05, Total 99.64. Its crystal structure (X-ray on a single crystal) was solved with R1=0.0506, wR2=0.1026, with an orthorhombic symmetry, space group Pnma, and a=24.080(5) Å, b=4.1276(8) Å, c=11.369(2) Å, V=1130.0(4) Å3, Z=4. Relatively to the model of Euler and Hellner (1960), this structure shows a significantly lower site occupancy factor for the tetrahedral Cu site (0.146 against 0.25). Among the five other metallic sites, Bi appears in the one with predominant Sb. Developed structural formula: Cu0.15Pb2(Pb0.53Sb0.47)(Pb0.46Sb0.54)(Sb0.75Pb0.19Bi0.06)S6; the reduced one: Cu0.58Pb12.72(Sb7.04Bi0.24)S24. The formation of such a Cu-poor variety seems to be related to specific paragenetic conditions (absence of coexisting galena), or to crystallochemical constraints (minor Bi). To cite this article: Y. Moëlo et al., C. R. Geoscience 334 (2002) 529–536. 相似文献