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本文以广西龙水水政顶倾竖褶皱构造变形分析为基础,根据含金石英脉与非含金石英脉的变形差异,认为作用于岩层上的主剪切应力(σ_s)与主压缩应力(σ_p)随时间(t)的变化是导致岩层褶皱过程中石英脉多样性变形的主因;阐述了上述模型的动态应力场及其动力学过程;提出了构造变形的分解作用、水力压裂作用与裂开-愈合作用是石英脉形成的新构造机制。 相似文献
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This paper presents sedimentary evidence for rapid englacial debris entrainment during jökulhlaups. Previous studies of jökulhlaup sedimentology have focused predominantly on proglacial impact, rather than depositional processes within glaciers. However, observations of supraglacial floodwater outbursts suggest that englacial sediment emplacement is possible during jökulhlaups. The November 1996 jökulhlaup from Skei?arárjökull, Iceland presented one of the first opportunities to examine englacial flood deposits in relation to former supraglacial outlets. Using observations from Skei?arárjökull, this paper identifies and explains controls on the deposition of englacial flood sediments and presents a qualitative model for englacial jökulhlaup deposition. Englacial jökulhlaup deposits were contained within complex networks of upglacier‐dipping fractures. Simultaneous englacial deposition of fines and boulder‐sized sediment demonstrates that englacial fracture discharge had a high transport capacity. Fracture geometry was an important control on the architecture of englacial jökulhlaup deposits. The occurrence of pervasively frozen flood deposits within Skei?arárjökull is attributed to freeze‐on by glaciohydraulic supercooling. Floodwater, flowing subglacially or through upglacier‐dipping fractures, would have supercooled as it was raised to the surface faster than its pressure‐melting point could increase as glaciostatic pressure decreased. Evidence for floodwater contact with the glacier bed is supported by the ubiquitous occurrence of sheared diamict rip‐ups and intra‐clasts of basal ice within jökulhlaup fractures, deposited englacially some 200–350 m above the bed of Skei?arárjökull. Evidence for fluidal supercooled sediment accretion is apparent within stratified sands, deposited englacially at exceptionally high angles of rest in the absence of post‐depositional disturbance. Such primary sediment structures cannot be explained unless sediment is progressively accreted to opposing fracture walls. Ice retreat from areas of former supraglacial outbursts revealed distinct ridges characterized by localized upwellings of sediment‐rich floodwater. These deposits are an important addition to current models of englacial sedimentation and demonstrate the potential for post‐jökulhlaup landform development. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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Y、D、L井组是平顶山盐厂仅有的三对水力压裂连通井组,也是平顶山盐厂卤水的主要产供者,Y井组为设计水力压裂连通井组,D、L井组为改造连通井组,由原对流单井改造而成。本文通过三井组连通通道所处层位的判断及其运行特点的解析,对两种连通井组作出比较,并对平顶山盐田采卤方法提出建议 相似文献
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Sergee A. Shapiro Pascal Audigane & Jean-Jacques Royer 《Geophysical Journal International》1999,137(1):207-213
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Conduit system and formation mechanism of heat fluids in diapiric belt of Yinggehai basin, China 总被引:3,自引:0,他引:3
The conduit system of heat fluids in diapiric belt of Yinggehai basin is dominantly vertical faults and fractures. Detailed
research on the formation mechanism and their occurrence features shows that the faults and fractures can be classified into
three types: intrastratal dispersive hydrofracture, puncturing fault and upwarping-extensional fault. The development of the
fault and fracture system not only resulted in the changes of the temperature and pressure fields in the basin, but also affected
the hydrocarbon migration in the overpressured system. These faults and fractures constituted the main pathways for vertical
hydrocarbon migration, and opening and closing intermittently led to episodic expulsion of overpressured fluid compartment.
Thus there formed the pool-forming model of multi-source mixing and ploy-stage migration and accumulation for hydrocarbons
in the Yinggehai basin.
Project jointly supported by the Ministry of Science and Technology of China (Grant No.95-Pre-39) and the National Natural
Science Foundation of China (Grant No. 49732005), and A Hundred Excellent Researchers Foundation from the Ministry of Land
and Resources. 相似文献
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Three‐dimensional texture of natural pseudotachylyte: Pseudotachylyte formation mechanism in hydrous accretionary complex 下载免费PDF全文
Yohei Hamada Gaku Kimura Jun Kameda Asuka Yamaguchi Mari Hamahashi Rina Fukuchi Yujin Kitamura Shin'ya Okamoto 《Island Arc》2018,27(2)
Melt‐origin pseudotachylyte is the most reliable seismogenic fault rock. It is commonly believed that pseudotachylyte generation is rare in the plate subduction zone where interstitial fluids are abundant and can trigger dynamic fault‐weakening mechanisms such as thermal pressurization. Some recent studies, however, have discovered pseudotachylyte‐bearing faults in exhumed ancient accretionary complexes, indicating that frictional melting also occurrs during earthquakes in subduction zones. To clarify the pseudotachylyte generation mechanism and the variation of slip behavior in the plate subduction zone, a pseudotachylyte found in the exhumed fossil accretionary complex (the Shimanto Belt, Nobeoka, Japan) was re‐focused and microscopic and three‐dimensional observations of the pseudotachylyte‐bearing fault were performed based on optical, electron, and X‐ray microscope images. Based on the patterns contained in the fragment, the pseudotachylyte is divided into four domains, although no clear domain boundaries or layering structures are not found. Three‐dimensional observation also suggests that the pseudotachylyte were fragmented or isolated by cataclasite or carbonate breccia. The pseudotachylyte was rather injected into the surrounding carbonate breccia, which is composed of angular fragments of the host rock and a matrix of tiny crystalline carbonate. The pseudotachylyte volume was extracted from the X‐ray microscope image and the heat abundance consumed by the pseudotachylyte generation was estimated at 2.18 MJ/m2, which can be supplied during a slip of approximately 0.5 m. These observations and calculations, together with the results of the previous investigations, suggest hydrofracturing and rapid carbonate precipitation that preceded or accompanied the frictional melting. Dynamic hydrofracturing during a slip can be caused by rapid fluid pressurization, and can induce abrupt decrease in fluid pressure while drastically enhancing the shear strength of the shear zone. Consequently, frictional heating would be reactivated and generate the pseudotachylyte. These deformation processes can explain pseudotachylyte generation in hydrous faults with the impermeable wall rock. 相似文献
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影响水力压裂效果的因素及人工神经网络评价 总被引:2,自引:2,他引:0
水力压裂是低渗透油气田提高开采效益的主要技术手段之一,但是影响水力压裂效果的因素较多,如地质特征、储层物性和地层能量等。为了达到理想的压裂效果,就要综合考虑各个影响因素之间的相互关系,找出影响压裂效果的主要因素。本文利用人工神经网络方法建立了数学评估模型并对已有的大量生产数据进行了网络训练和方法验证。结果证明所建立的压裂井潜能评估模型稳定性好,预测精度较高,对油田水力压裂的选井评层及产能预测具有一定的指导意义。 相似文献