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891.
892.
The high-temperature and pressure experimental data of garnet, sillimantite and biotite-bearing potash feldspar gneiss (SGBG,
natural block rock) has shown that metamorphic reactions between garnet and melt, and mineral assemblage evolutional features
are not only controlled byP-T condition, but also genetically correlate with dehydration-melting of biotite and partial melting of felsic minerals. Combining
experimental data with theoretical analyses, the genetic mechanism of metamorphic reaction and its dynamic significance have
been demonstrated in the process of metamorphic evolution of khondalite series on the border of Jin (Shanxi Province)-Inner
Mongolia.
Project supported by the Youth Geologist Foundation of Ministry of Geology and Mineral Resources of China, the Post-docter
Foundation and the National Natural Science Foundation of China (Grant No. 49572138). 相似文献
893.
A hybrid discrete-continuum approach has been presented in this paper to simulate water flow in the near and far fields of deformable fractured rocks. In the near field, the discrete model is used; while in the far field, the equivalent continuum model is employed. The discrete element method (with the static relaxation algorithm) is used in the near field and the boundary integral equation method in the far field. Along the interface of these two domains, both mechanical and hydraulic compatibility conditions are satisfied. Fully coupled hydro-mechanical analysis can be conducted in the combined near and far fields. Application to a dam foundation problem has demonstrated the capability of the developed approach. 相似文献
894.
腾冲、长白山、五大连池新生代火山岩Sr、Nd、Pb同位素地球化学特征 总被引:5,自引:2,他引:3
概括了腾冲、长白山、五大连池新生代火山岩岩石学、岩石化学基本特征,探讨了Sr、Nd、Pb同位素地球化学特征和岩浆源区性质。腾冲火山岩为高钾钙碱性岩系,高87Sr/86Sr、高206Pb/204Pb、208Pb/204Pb、低143Nd/144Nd,岩浆源区为俯冲带再循环富集地幔。长白山火山岩为超钾钙碱性岩系,低Sr高87Sr/86Sr,εNd为-23—+29,Pb同位素组成变化不大,岩浆源区为俯冲带再循环地幔。五大连池火山岩为超钾碱性岩系,高87Sr/86Sr、低143Nd/144Nd和206Pb/204Pb、208Pb/204Pb,岩浆源区为地幔内部交代作用所产生的富集地幔。 相似文献
895.
HOU Dujie ZHANG Linye WANG Tieguan Research Centre for Organic Geochemistry Jianghan Petroleum Institute Jingzhou Hubei Applied Geochemistry Section Dept. ofGeosciences China University of Petroleum Changping Beijing Geochemistry Research Section Shengli Petroleum Geological Sciences Institute Shengli Petroleum Administration Bureau Dongying Shandong 《《地质学报》英文版》1998,72(4):399-408
Four typical distribution patterns of pentacyclic triterpenoid hydrocarbons (types A-D) are distinguished in the low-mature source rocks from eastern China. Type A has a relatively high content of pentacyclic triterpenes. It exists in immature sediments and the distribution and abundance of triterpenes vary with the maturity of the sediments. An unknown C30 triterpene (UCT2) has also been detected in very shallow sediments. This compound is very unstable and disappears rapidly with the increase of depth. Type B is characterized by a relatively high amount of 17α(H), 21β(H)-30-homohopane. This kind of distribution pattern is common in coals and terrestrial sediments of low maturity. Type C has a relatively high content of diahopane and neohopane series. The analysis shows that this distribution pattern may have an indirect relationship with the input of higher plants despite its microbial source. There are C30-unconfirmed triterpane (UCT2) and a relatively high content of C35 hopane in type D. The dist 相似文献
896.
Reform of Carbonate Rock Subsurface by Crustose Lichens and Its Environmental Significance 总被引:5,自引:0,他引:5
CAO Jianhua WANG FuxingInstitute of Karst Geology Chinese Academy of Geological Sciences Guilin Guanxi Xiao Pinfang Liu Xinzhu 《《地质学报》英文版》1998,72(1):94-99
Crustose lichens are distributed extensively in karst areas in Southern China. They can be found on the surface of carbonate rocks. Through biophysical and biochemical processes, crustose lichens reform the subsurface of carbonate rocks and in the meanwhile change their physical and chemical properties: (1) the mechanical strength decreases by 17.04° on average (up to 33.2° ); (2) the chemical solution surface area increases from 28.26% to 75.36% (lichen microholes considered only); and (3) the water-holding capacity is greatly improved. Comparative field experiments between biokarst samples underneath crustose lichens and fresh rock samples with the same composition and texture show that the corrosional rate of carbonate rocks of the former is 1.264-1.643 times higher than that of the latter. Crustose lichens are considered as an activator of the surface corrosion of carbonate rocks. 相似文献
897.
A polymetallic zone dominated by U-W mineralization was found in Northeast Guangxi. Distributed along the east contact zone
of a complex granite mass, it extends for about 100 km in length, with more than fifty deposits and prospects embraced. The
deposits show a wide range of genetic types, related to the granite, from magmatic (including pegmatite and skarn deposits)
through hydrothermal mineralizations (hypo-, meso- and epithermal) all the way to tin placers, constituting a very intact
metallogenetic series of granites. The epithermal U-W deposits are considered as a new type for their unique geological and
geochemical characters, such as the paragenesis of U and W and the large time gap (> 40 Ma) between ore and granite.
This project was financially supported by the Open Lab. of Ore Deposit Geochemistry, Chinese Academy of Sciences. 相似文献
898.
非迭代,非线性二维重力反演计算方法 总被引:1,自引:0,他引:1
本文叙述了非迭代、非线性二维重力反演方法的原理、模型计算及应用效果等。与以往诸多的求界面重力反演方法相比,该法的主要特点是:将界面的深度用一幂级数的形式表示,且幂级数系数的计算与界面上下地层的密度差无关。因此,一旦求出了幂级数的系数,由界面的密度差可直接得到界面的深度,且幂级数收敛的速度很快。 相似文献
899.
遗传规划在岩石力学中的应用 总被引:1,自引:0,他引:1
本文探讨了遗传规划这一新的优化方法在岩石力学参数确定中的应用。由于影响岩石力学性能的各因素之间关系不明确,而遗传规划特别适用于各影响因素之间因果关系不明确的复杂非线性问题。它为预测岩石力学性能提供了一条新的技术途径。通过例子,说明该方法的实用性。 相似文献
900.
估算岩石断裂面粗糙度的一种分形模型 总被引:3,自引:0,他引:3
提出了一种更为简单的估算岩石断裂面粗糙度值的分形模型,可用来模拟岩石断裂面剖面线。断裂面愈粗糙,其分维值也愈大,并建立了分维值与JRC值之间的经验方程。 相似文献