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101.
Hydrothermal mineral assemblages and related hydrothermally enhanced fracturing are common in the Precambrian Dengying Formation of Central Sichuan Basin. Petrographic and geochemical analyses of core samples show that the hydrothermal dolomite reservoirs of Dengying Formation consist of four main types of pores in the reservoir facies. These include: 1) hydrothermal dissolution vug(or pore), 2) intercrystalline pore, 3) residual inter-breccia vug(or pore), and 4) enlarged dissolved-fracture. There are three different fabrics dolomite in hydrothermal dolomite reservoirs, namely, saddle dolomite, fine-medium dolomite and micritic dolomite. Micritic dolomite is the original lithology of host rock. Saddle dolomite with curved or irregular crystal faces was directly crystallized from hydrothermal fluids(average temperature 192°C). Fine-medium dolomites are the products of recrystallization of micritic dolomite, resulting in abnormal geochemical characteristics, such as slight depletion of δ18O, significant enrichment of Mn-Fe and 87Sr/86Sr, and positive Eu anomaly. A model for the distribution of various hydrothermal dolomite reservoir facies is proposed here, which incorporates three fundamental geological controls: 1) extensional tectonics and tectono-hydrothermal events(i.e., the Xingkai Taphrogenesis of Late Sinian-Early Cambrian, and Emei Taphrogenesis of Late Permian), 2) hydrothermal fluid storage in clastic rocks with large thickness(e.g., Nanhua System of Chengjiang Formation and part of Doushantuo Formation), and 3) confining bed for hydrothermal fluids(such as, the shale in Qiongzhusi Formation). The supply of hydrothermal fluid is critical. Large basement-rooted faults and associated grid-like fracture system may function as the channels for upward migration of hydrothermal fluid flow. The intersection of the above-mentioned faults(including the conversion fault), especially transtensional sags above negative flower structures on wrench faults can serve as a key target for future hydrocarbon exploration. 相似文献
102.
QUATERNARY GLACIATION SERIES ANDGLACIAL LANDFORM IN GONGWANG MOUNTAINS INNORTHEAST PART OF YUNNAN PROVINCE, CHINA 总被引:1,自引:0,他引:1
况明生 《中国地理科学(英文版)》1997,7(2):180-190
Therearemanyquaternaryglaciallandformsinalpineareasahave3100ma.s.1.intheGongWangMountainsinthenortheastpartofYunnanProvinceofChina.TheglaciationseriesandtheglaciallandformsoftheQuaternaryhaveoncebeencoveredinanarticlesketchily(Yietal.,1991).Onthebasisoffieldinvestigationsinrecentyears,we'11goastepfurthertodiscusstheQuaternaryglaciationseriesandtheglacierlandfo~sthereinthisPaper.I.TabsQU~ANANYG~W~TheGOngWangMountainsissituatedbetweentwobranchesoftheJinshaRiver,theXiaojiangandthePudu… 相似文献
103.
辽西地震重点监视区桥梁震害预测 总被引:1,自引:0,他引:1
采用统计回归方法,对辽西地震重点监视防御区内4条国家级公路的桥梁133座、4次国有铁路的桥梁331座,以桥梁震害等级划分原则,求取其震害指数、判定震害等级。 相似文献
104.
矿物和玻璃中NaK—边的同步辐射XANES研究 总被引:2,自引:0,他引:2
本文利用同步辐射的NaK-边X射线近边结构谱(XANES)研究了含Na矿物NaK-边的特征谱,其谱的能量位置随着配位数垢增加而增大,同时建立了含磷(P)的钠玻璃中NaK-边的能量,随着P的含量增加而增大,由此表明本方法可以作为研究含Na矿物和Na玻璃的配位与局部结构的新方法。 相似文献
105.
106.
YANG Jie LIAO Mingsheng YANG Wen ZHANG Li YANG Jie Master National Laboratory for Information Engineering in Survey-ing Mapping Remote Sensing WTUSM Luoyu Road Wuhan China 《地球空间信息科学学报》1999,2(1):100-103
In Synthetic Aperture Radar (SAR) interferometry, the precise co-registration is a key problem to obtain the fine interferogram. Theoretically, 1/10 pixel accuracy is essential. Once the control points are determined, the relative rectification (pixel re-sampling)is also the important procedure. In this paper,a piecewise transformation algorithm based on Delaunay Tessellation algorithm is developed. The strategy is to "anchor" geographically all control points and transform the imagery on the basis of triangle by triangle. The piecewise algorithm, the accuracy evaluation and the preliminary results are described. The experiment result shows that the piecewise transformation out-performes the traditional polynomial transformation. 相似文献
107.
探讨了基于遥感和地理信息系统手段进行洪涝灾害灾情分析和损失估计的途径,研究了利用灾后一定时期内的遥感影像再现淹没状况的方法。 相似文献
108.
二维高分辨自动地电阻率探测地下洞穴技术 总被引:4,自引:1,他引:4
高分辨地电阻率系统主要用于地下洞体探测。采用单极-偶极连续二维剖面观测,地采集的资料应用目标异常匹配滤波法或交汇法再现地下异常体形象。 相似文献
109.
110.
Dien Li G. M. Bancroft M. Kasrai M. E. Fleet B. X. Yang X. H. Feng K. Tan Mingsheng Peng 《Physics and Chemistry of Minerals》1994,20(7):489-499
Sulfur K-edge x-ray absorption spectra (XANES and EXAFS) and L-edge XANES of sphalerite (ZnS), chalcopyrite (CuFeS2) and stannite (Cu2FeSnS4) have been recorded using synchrotron radiation. The K- and L-edge XANES features are interpreted using a qualitative MO/energy band structure model. The densities of unoccupied states at the conduction bands of sphalerite, chalcopyrite and stannite are determined using S K- and L-edge XANES features (up to 15 eV above the edge), combined with published metal K-edge XANES. The SK- and L-edge XANES also indicate that, for sphalerite, the Fe2+ 3d band at the fundamental gap has little or no bonding hybridization with S 3p and S 3s orbitals; for chalcopyrite, the Cu+ 3d and Fe3+ 3d bands have strong mixing with S 3p and S 3s states, while for stannite the Cu+ 3d band strongly hybridizes with S 3p and S 3s orbitals, but the Fe2+ 3d band does not. The post-edge XANES features (15–50 eV above the edge) of sphalerite, chalcopyrite and stannite are similar. These features are related to the tetrahedral coordination of sulfur in all these structures, and interpreted by a multiple scattering model. The resonance energies from both the K-edge and L-edge XANES for these minerals are well correlated with reciprocal interatomic distances and lattice spaces. Sulfur K-edge EXAFS analyses using Fourier transform and curve fitting procedures are presented. Comparison of the structural parameters from EXAFS with x-ray structure data shows that the first shell bond distances (BD) from EXAFS are usually accurate to ±0.02 Å, and that coordination numbers (CN) are generally accurate to ±20 percent. For sphalerite, EXAFS analysis yields the structure parameters for the first three neighbour shells around a sulfur atom; the BD and CN even for the third shell are in close agreement with the x-ray structure, and the Debye-Waller term decreases from the first shell to the third shell. It is shown that sphalerite (ZnS) is a good model compound for EXAFS analysis of sulfur in chalcogenide glasses and metalloproteins. 相似文献