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51.
本文应用分数维理论,计算了阿尔金活动断裂带的分数维值,从分数维值的大小反映断裂构造复杂程度的观点出发,分析了阿尔金活动断裂带的活动特点。 相似文献
52.
当前反射地震学研究中的问题浅析 总被引:3,自引:4,他引:3
反射地震学作为地震学应用于国民经济建设的分支学科取得了巨大的成功。它在矿产资源勘探、工程建设与环境、自然灾害预测等各种领域发挥了不可替代的作用,特别是在能源开发中功不可殁。另一方面,反射地震学在广泛的工业应用中全面地完善和发展了地震学的理论、方法和技术。时至今日,反射地震学的发展已经从经典理论方法的研究走向更加与客观介质密切相关的深层次研究新阶段,这些问题是,反射地震学从单纯的构造研究走向地层岩性研究,与此有关的是从偏移构造成像步入层析成像、利用单波单分量数据转向应用多波多分量数据、假设地层为固体弹性介质转向双相孔隙介质、各向同性研究转向各向异性研究以及经典的一些方法技术与现代新技术同时使用等。本文对这些方面的研究现状进行概要的分析。 相似文献
53.
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55.
吉林省西林河金矿构造特征及找矿方向 总被引:2,自引:0,他引:2
对矿区划分了太古宙、元古宙、中生代和新生代四个构造层;整个矿区为一棋盘格子形构造体系;主干构造形迹为由东、中、西三个韧性挤压剪切带,金矿的主要成矿构造是西部韧性挤压、剪切带,主要找矿方向为西带F6及其派生的近南北向剪切断裂群。 相似文献
56.
根据实际资料分析研究,逆断裂破裂位错向上传播至松散层中有4种消减形式:端部分叉、从断裂向褶皱转换、破裂在松散层中的吸收与尖灭及逆断层前方碎砾物质的扰动变形等。端部分叉与扰动变形的消减可能与突发性位错相关;上覆层的褶皱及位错在松散层中的尖灭则多属弹-塑转换型的消减方式 相似文献
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58.
Technical difficulties associated with excavation works in tectonized geological settings are frequent. They comprise instantaneous
and/or delayed convergence, sudden collapse of gallery roof and/or walls, outpouring of fault-filling materials and water
inflows. These phenomena have a negative impact on construction sites and their safety. In order to optimize project success,
preliminary studies on the reliability of rock material found on site are needed. This implies in situ investigations (surface
mapping, prospective drilling, waterflow survey, etc.) as well as laboratory investigations on rock samples (permeability
determination, moisture and water content, mineralogy, petrography, geochemistry, mechanical deformation tests, etc.). A set
of multiple parameters are then recorded which permit better insight on site conditions and probable behavior during excavation.
Because rock formations are by nature heterogeneous, many uncertainties remain when extrapolating large-scale behavior of
the rock mass from analyses of samples order of magnitudes smaller. Indirect large-scale field investigations (e.g. geophysical
prospecting) could help to better constrain the relationships between lithologies at depth. At a much smaller scale, indirect
analytical methods are becoming more widely used for material investigations. We discuss in this paper X-ray computed tomography
(XRCT) and neutron tomography (NT), showing promising results for 3D petrographical investigations of the internal structure
of opaque materials. Both techniques record contrasts inside a sample, which can be interpreted and quantified in terms of
heterogeneity. This approach has the advantage of combining genetic parameters (physico-chemical rock composition) with geometric
parameters resulting from alteration or deformation processes (texture and structure). A critical analysis of such 3D analyses
together with the results of mechanical tests could improve predictions of short- and long-term behavior of a rock unit. Indirect
methods have the advantage of being non-destructive. However, as it is the case with large-scale geophysical surveying, XRCT
and NT are affected by several error factors inherent to the interaction of a radiation modality (X-ray or neutron beam) with
the atomic structure of the investigated materials. Recorded signals are therefore in particular cases not artifact-free and
need to be corrected in a subsequent stage of data processing. 相似文献
59.
粤东嵩溪银锑矿床成矿构造及矿化富集规律浅析 总被引:2,自引:1,他引:2
论述了嵩溪银锑矿床的地质特征、矿脉形态特征及组构特征,通过分析得出矿床成矿断裂的产生有四个阶段,其中银、锑矿化主要与第二、三阶段有关。 相似文献
60.
J. M. Léger J. Haines C. Chateau G. Bocquillon M. W. Schmidt S. Hull F. Gorelli A. Lesauze R. Marchand 《Physics and Chemistry of Minerals》2001,28(6):388-398
The structure of the cristobalite-like polymorph of phosphorus oxynitride PON has been refined using neutron powder diffraction
data. It is tetragonal, space group I&4macr;2d, Z=4. The four P–(O,N) distances are equal but the tetrahedron is compressed along c. In AX2 or ABX4 compounds, the tetragonal I&4macr;2d or I&4macr; structure is obtained when the average ratio of the cation to anion radius is below 1.186, whereas the tetragonal P41212 or orthorhombic C2221 structure is obtained at low temperatures for larger ratios. The cell parameters of this PON polymorph have been determined
as a function of hydrostatic pressure by in situ angle dispersive X-ray powder diffraction in a diamond-anvil cell. Under
truly hydrostatic pressure, a strong anisotropic behavior is observed with the c parameter being nearly incompressible. Very slight anisotropic stress strongly modifies the high-pressure behavior. According
to the pressure-temperature conditions of treatment, three phases, cristobalite-, moganite-, and quartz-like, have been obtained
by quenching experiments, and the P–T phase diagram of PON was derived. The high-pressure behavior of the α-quartz, moganite, and cristobalite-like polymorphs
of PON and SiO2 is discussed.
Received: 7 August 2000 / Accepted: 21 January 2001 相似文献