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131.
文章从赋矿层位、构造入手,研究了金矿形成的特殊矿源层及构造作用下的成矿裂隙特征,认为小尖山金矿位于全区含金丰度最高的石炭系下统雅满苏组地层内,差异的矿化特征主要由不同的裂隙导致形成. 相似文献
132.
藤铁铁矿位于鱼鹿岩枝东接触带中段,该矿体为铁、铜、锡共(伴)生矿床.受断裂带、岩体侵入接触带、夕卡岩带和鱼鹿岩枝控制.据此总结出该区"三带一体"的成矿特征. 相似文献
133.
High-resolution structures of the Landers fault zone inferred from aftershock waveform data 总被引:2,自引:0,他引:2
High-frequency body waves recorded by a temporary seismic array across the surface rupture trace of the 1992 Landers, California, earthquake were used to determine fault-zone structures down to the seismogenic depth. We first developed a technique to use generalized ray theory to compute synthetic seismograms for arbitrarily oriented tabular low-velocity fault-zone models. We then generated synthetic waveform record sections of a linear array across a vertical fault zone. They show that both arrival times and waveforms of P and S waves vary systematically across the fault due to transmissions and reflections from boundaries of the low-velocity fault zone. The waveform characteristics and arrival-time patterns in the record sections allow us to locate the boundaries of the fault zone and to determine its P - and S -wave velocities independently as well as its depth extent. Therefore, the trade-off between the fault-zone width and velocities can be avoided. Applying the method to the Landers waveform data reveals a low-velocity zone with a width of 270–360 m and a 35–60 per cent reduction in P and S velocities relative to the host rock. The analysis suggests that the low-velocity zone extends to a depth of ∼7 km. The western boundary of the low-velocity zone coincides with the observed main surface rupture trace. 相似文献
134.
Multi-borehole pumping and tracer tests on the 10 to 100-m scale were conducted in a fractured chalk aquitard in the Negev
Desert, Israel. Outcrop and core fracture surveys, as well as slug tests in packed-off intervals, were carried out at this
site to obtain the parameters needed for construction of a stochastic discrete fracture network (DFN). Calibration of stochastic
DFNs directly to the multiple borehole test data was inadequate. Instead, two equivalent deterministic DFN flow models were
used: the vertical-fractures (VF) model, consisting of only vertical fractures, and the fractures’ intersections (INT) model,
consisting of vertical and horizontal fractures with enhanced transmissivity at their intersections. Both models were calibrated
against the multi-borehole response of one pumping test and their predictions were tested against three other independent
pumping tests. The average accuracies of all transient drawdown predictions of the VF and INT models were 65 and 66%, respectively.
In contrast to this equality in average drawdown predictions of both models, the INT model predicted better important breakthrough
curve features (e.g., first and peak arrival times), than the VF model. This result is in line with previously assumed channeled
flow, derived from analytical analysis of these pumping and tracer tests.
Ronit Nativ, deceased, may her memory be blessed. 相似文献
135.
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137.
开挖边坡随机楔体稳定分析与加锚优化方法 总被引:1,自引:1,他引:1
随机楔体的破坏是岩石开挖边坡中常见的破坏类型之一,在对组成楔体的结构而调查统计的基础上,应用随机模拟的方法,生成开挖边坡的三维裂隙网络,进一步运用随机搜索方法与块体理论,搜索出边坡面上的随机楔体,进行楔体的稳定分析,采用风险设计的理论,建立系统锚杆的优化设计方法,将研究结果应用于小湾水电站进水口开挖边坡的稳定分析与锚固优化设计中,得到了较为可信的结果。 相似文献
138.
松辽盆地深部反射地震探查 总被引:14,自引:4,他引:14
概述了近年来用近垂直反射地震方法研究不同大地构造单元的地壳结构和深部构造问题所取得的基本成果,说明了在松辽盆地内所进行的两次深反射地震探查,包括位置、科学目标、资料采集、处理技术和基本结果,利用延长排列所得到的约42km长共炮点资料,求出松辽盆地地壳平均速度约为6.197km/s。通过初步解释,认为在上部地壳存在多组低角度断裂、中下部地壳构造具有更为复杂的震相、Moho震相比较清晰,多处出现与Moho震相斜交的震相。 相似文献
139.
IntroductionThe tectono-physical background and dynamic environmental features of strong earthquakes have long been studied from different viewpoints by seismologists both in domestic and abroad. Many controlling factors include the crust structure, lithological environment, tectonic conditions, the stress state, heat flow distribution and hydrodynamic effects at depth, etc. Some of the studies have established a foundation for researching and recognizing the spatial distribution of potential … 相似文献
140.