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51.
This paper reviews the data concerning the fracture network and the hydraulic characteristics of faults in an active zone of the Gulf of Corinth. Pressure gap measured through fault planes shows that in this area the active normal faults (Aigion, Helike) act, at least temporarily and locally, as transversal seal. The analysis of the carbonate cements in the fractures on both the hangingwall and the footwall of the faults also suggests that they have acted as local seals during the whole fault zone evolution. However, the pressure and the characteristics of the water samples measured in the wells indicate that meteoric water circulates from the highest part of the relief to the coast, which means it goes through the fault zones. Field quantitative analysis and core studies from the AIG-10 well have been performed to define both regional and fault-related fracture networks. Then laboratory thin section observations have been done to recognize the different fault rocks characterizing the fault zone components. These two kinds of approach give information on the permeability characteristics of the fault zone. To synthesize the data, a schematic conceptual 3D fluid flow modeling has been performed taking into account fault zone permeability architecture, sedimentation, fluid flow, fault vertical offset and meteoric water influx, as well as compaction water flow. This modeling allows us to fit all the data with a model where the fault segments act as a seal whereas the relays between these segments allow for the regional flow from the Peloponnese topographic highs to the coast. 相似文献
52.
The NW-trending Bucaramanga fault links, at its southern termination, with the Soapaga and Boyacá faults, which by their NW trend define an ample horsetail structure. As a result of their Neogene reactivation as reverse faults, they bound fault-related anticlines that expose the sedimentary fill of two Early Jurassic rift basins. These sediments exhibit the wedge-like geometry of rift fills related to west-facing normal faults. Their structural setting was controlled further by segmentation of the bounding faults at approximately 10 km intervals, in which each segment is separated by a transverse basement high. Isopach contours and different facies associations suggest these transverse anticlines may have separated depocenters of their adjacent subbasins, which were shaped by a slightly different subsidence history and thereby decoupled. The basin fill of the relatively narrow basin associated with the Soapaga fault is dominated by fanglomeratic successions organized in two coarsening-upward cycles. In the larger basin linked to the Boyacá fault, the sedimentary fill consists of two coarsening-upward sequences that, when fully developed, vary from floodplain to alluvial fan deposits. These Early Jurassic rift fills temporally constrain the evolution of the Bucaramanga fault, which accommodated right-lateral displacement during the early Mesozoic rift event. 相似文献
53.
3-D seismic structure of the source area of the 1993 Latur, India, earthquake and its implications for rupture nucleations 总被引:1,自引:0,他引:1
The Latur earthquake (Mw 6.1) of 29 September 1993 is a rare stable continental region (SCR) earthquake that occurred on a previously unknown blind fault. In this study, we determined detailed three-dimensional (3-D) P- and S-wave velocity (Vp, Vs) and Poisson's ratio (σ) structures by inverting the first P- and S-wave high-quality arrival time data from 142 aftershocks that were recorded by a network of temporary seismic stations. The source zone of the Latur earthquake shows strong lateral heterogeneities in Vp, Vs and σ structures, extending in a volume of about 90 × 90 × 15 km3. The mainshock occurred within, but near the boundary, of a low-Vp, high-Vs and low-σ zone. This suggests that the structural asperities at the mainshock hypocenter are associated with a partially fluid-saturated fractured rock in a previously unknown source zone with intersecting fault surfaces. This might have triggered the 1993 Latur mainshock and its aftershock sequence. Our results are in good agreement with other geophysical studies that suggest high conductivity and high concentration of radiogenic helium gas beneath the source zone of the Latur earthquake. Our study provides an additional evidence for the presence of fluid related anomaly at the hidden source zone of the Latur earthquake in the SCR and helps us understand the genesis of damaging earthquakes in the SCR of the world. 相似文献
54.
Ir. Lahuddin M S Zulkifli Nasution 《湿地科学》2006,4(3):161-167
1 INTRODUCTIONQuality of chemical properties of flooded soils isgenerally determined by salinity and alkalinity,bothof these acts as inhibiting factors of plant growth.Thecorrelation of electrical conductivity and other analysisindex has been reported by … 相似文献
55.
Nadia Curetti Davide Levy Alessandro Pavese Gabriella Ivaldi 《Physics and Chemistry of Minerals》2006,32(10):670-678
The elastic properties of coexisting natural 3T and 2M
1 phengite samples (Cima Pal, Sesia Zone; Val Savenca; Western Alps, Italy) with similar chemical compositions have been studied by room temperature–high pressure powder diffraction, using synchrotron radiation on the ID9A beam-line at ESRF (Grenoble, France). The P–V curves have been modelled by the Birch–Murnaghan model; a third-order expansion fitted to the experimental data yields for 3T and 2M
1 K
0=60.4(±0.7) GPa, K′=5.79(±0.11) at V
0=703.8851 Å3, and K
0=57.3(±1.0) GPa, K′=6.97(±0.24) at V
0=938.8815 Å3, respectively. The relative stability of 3T vs. 2M
1 has been explored as a function of pressure and temperature in terms of configuration and deformation contributions to the Gibbs energy, using the elastic properties determined here and other thermodynamic parameters from earlier investigations. The results presented agree with the hypothesis of stability of the 3T polytype in the high pressure regime. 相似文献
56.
Aierken Sidike X.-M. Wang Alifu Sawuti H.-J. Zhu I. Kusachi N. Yamashita 《Physics and Chemistry of Minerals》2006,33(8-9):559-566
Natural calcite from Kuerle, Xinjiang, China, shows orange-red fluorescence when exposed to short-wave ultraviolet (UV) light (Hg 253.7 nm). Photoluminescence (PL) emission and excitation spectra of the calcite are observed at room temperature in detail. The PL emission spectrum under 208 nm excitation consists of three bands: two UV bands at 325 and 355 nm and an orange-red band at 620 nm. The three bands are ascribed to Pb2+, Ce3+ and Mn2+, respectively, as activators. The Pb2+ excitation band is observed at 243 nm, and the Ce3+ excitation band at 295 nm. The Pb2+ excitation band is also observed by monitoring the Ce3+ fluorescence, and the Pb2+ and Ce3+ excitation bands, in addition to six Mn2+ excitation bands, are also observed by monitoring the Mn2+ fluorescence. These indicate that four types of the energy transfer can occur in calcite through the following processes: (1) Pb2+ → Ce3+, (2) Pb2+ → Mn2+, (3) Ce3+ → Mn2+ and (4) Pb2+ → Ce3+ → Mn2+. 相似文献
57.
在分析戈壁沙漠地区地球物理特征的基础上,针对性的提出了解决煤田地质构造问题的方法,包括三维地震野外施工方法的选取、施工因素的选择、资料处理手段;并以获得的实际地质成果证实三维地震在解决复杂地质构造问题的可行性。 相似文献
58.
59.
利用Java-X3D实现地震层位三维可视化 总被引:1,自引:0,他引:1
地震层位三维可视化可以提供形象化的地震层位三维特征,便于地震资料的后期解释.在叙述地震层位三维可视化技术原理、目标、方法的基础上,尝试利用Java-X3D技术实现地震层位三维可视化,并利用实际坐标数据,实现了在Internet上跨平台的地震层位及地质构造三维可视化模拟,取得了良好的效果. 相似文献
60.
C1相干算法是计算每道的横测线和相邻纵测线的互相关,依据相干值来判断地层和岩性的横向不均匀性。根据互相关原理,提出了相干体算法中二维和三维C1算法的内容及其具体实现。通过对实际三维地震资料的处理,结合已知地质资料,证明C1相干技术在三维地震资料的断层解释方面有着明显的效果。 相似文献