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991.
992.
流体地质填图是一种全新的地质调查及找矿方法。本次研究选择云南巍山-永平矿集区进行流体地质填图试验,研究了矿集区的控矿地质要素、各种主要的矿床(点)特征、成矿流体子系统及流域、流体的盐度与均一温度、流体的气液相成分、微量元素含量、稳定同位素特征及成矿流体的浓集中心。得到的流体地质图基本反映了本区成矿流体的性质与状态,反映了两个成矿流体子系统的基本特征,圈字了2个成矿流体子系统的流域范围及7个成矿流体浓集中心。这些浓集中心与已知矿化点分布、化探异常及有利的地质条件基本吻合,成为该区进一步找矿预测的重要依据之一。本项目的实践表明,流体地质填图不失为一种有效的找矿手段。 相似文献
993.
将原始数据转换为分析型数据,增强用户对海量数据的分析能力,是数据仓库技术最核心、最有价值的思想,也是数据仓库在气象领域应用的基础。该文针对天气预报领域数据空间性、瞬变性、物理性和多尺度性等特点,提出了五元组描述的天气预报分析型数据概念模型;总结了生成分析型数据的固定区域统计、划分区域统计、基本天气系统识别和天气学概念模型识别4种聚集变换,并对其关键技术进行了讨论。提出了基本天气系统自动识别的滤波-划分-测量算法,探讨了针对气象数据特点的模糊空间关系,定义了进行天气学概念模型识别的空间模糊产生式规则,并针对空间数据给出了定位条件等扩展。 相似文献
994.
John A. Knox 《Mathematical Geology》2000,32(2):203-215
The Fahrenheit-to-Celsius temperature-conversion equation is a basic component of many introductory earth science courses. Despite its simplicity, it presents a challenge to students and instructors alike because residents of the United States are unfamiliar with the Celsius scale. By solving for the point at which these two temperature scales are equal, it is possible to use the equations for temperature conversion as a springboard to more advanced topics. It is demonstrated that temperature-conversion equations and chaotic equations can be solved using identical numerical and graphical techniques. As a result, the fundamental concepts of chaos theory and numerical methods can be introduced to students in the context of the simplest equations in the earth sciences. These solution methods are applied to the quantitative theory of the extratropical cyclone as an example of the utility and broad scope of this educational approach. 相似文献
995.
996.
O. K. Manuel 《Journal of Earth System Science》2000,109(1):195-203
The notion of remote element synthesis has recently been modified to explain the presence of nucleogenetic isotopic anomalies
and decay products of short-lived nuclides by injection of a small amount ofexotic nucleogenetic material. Even with this modification, remote element synthesis seems inconsistent with the following observations:
相似文献
– | Evidence of coupled variations in the chemical and isotopic compositions of the source material for meteorites. |
– | Residual coupling of chemical and isotopic heterogeneities across planetary distances in the solar system today. |
– | The mass-fractionation relationship seen across isotopes of elements in the planetary system, in the solar wind, and in solar flares. |
– | Linkage of short-lived radioactivities with isotopic anomalies and with physical properties of their host grains, as expected for early condensate of fresh stellar debris. |
– | Temporal and spatial distributions of short-live nuclides and their decay products. |
– | Mirror-image (+ and −) isotopic anomalies in meteorite grains that sum to “normal” isotopic ratios, as expected of unmixed products of the same nuclear reactions that produced our bulk elements. |
– | The lac supporting evidence for “presolar” grains or nearby stars that injectedexotic material into the early solar nebula. |
997.
Summary Discontinuities or joints in the rock mass have various shapes and sizes. Along with the joint orientation and spacing, the
joint persistence, or the relative size of the joint, is one of the most important factors in determining the block sizes
of jointed rock masses. Although the importance of joint persistence on the overall rock mass strength has long been identified,
the impact of persistence on rock strength is in most current rock mass classification systems underrepresented. If joints
are assumed to be persistent, as is the case in most designs, the sizes of the rock blocks tend to be underestimated. This
can lead to more removable blocks than actually exist in-situ. In addition, a poor understanding of the rock bridge strength
may lead to lower rock mass strengths, and consequently, to excessive expenditure on rock support.
In this study, we suggest and verify a method for the determination of the block sizes considering joint persistence. The
idea emerges from a quantitative approach to apply the GSI system for rock mass classification, in which the accurate block
size is required. There is a need to statistically analyze how the distribution of rock bridges according to the combination
of joint orientation, spacing, and persistence will affect the actual size of each individual block. For this purpose, we
generate various combinations of joints with different geometric conditions by the orthogonal arrays using the distinct element
analysis tools of UDEC and 3DEC. Equivalent block sizes (areas in 2D and volumes in 3D) and their distributions are obtained
from the numerical simulation. Correlation analysis is then performed to relate the block sizes predicted by the empirical
equation to those obtained from the numerical model simulation. The results support the concept of equivalent block size proposed
by Cai et al. (2004, Int. J. Rock Mech. Min. Sci., 41(1), 3–19). 相似文献
998.
山东三山岛金矿床流体包裹体特征及其地质意义 总被引:5,自引:0,他引:5
三山岛金矿床位于莱州市三山岛—仓上断裂带内,矿石主要为蚀变岩和含金石英脉2种类型。随着胶东金矿床研究的深入和三山岛金矿资源的不断减少,对三山岛金矿床的成矿作用及深部开发前景问题研究具有更重要的意义。针对上述问题,对三山岛金矿床2种类型矿石的成矿流体特征进行对比研究,认为代表成矿早—中期的蚀变岩型矿石形成于中温(均一温度为325~240℃)、低盐度(2.07%~6.88%)、低密度(0.720~0.868g/cm3)、酸碱性不均匀(pH=3.27~10.43)、以氟化物和氯化物为成矿物质载体的还原性流体;代表成矿中—晚期的含金石英脉型矿石形成于中—低温(均一温度为306~160℃)、低盐度(1.05%~9.73%)、低密度(0.739~0.962g/cm3)、碱性(pH=9.25~9.85)、以氯化物和硫化物为成矿物质载体的还原性流体。成矿流体性质的转变反映了成矿流体处于由比较封闭到比较开放的构造环境的转变期,且成矿流体早期以原生岩浆水为主,后期有变质水、大气降水以及海水的参与作用。三山岛金矿成矿深度为2.5~5km,根据目前的开采深度推算其深部还有一定的资源量可供开发。 相似文献
999.
“小而肥”油藏油水分布特征及成因探讨——以海拉尔贝尔凹陷贝中油田为例 总被引:1,自引:0,他引:1
针对“小而肥”油田油气成藏特点,以贝尔凹陷贝中油田为例,在对其探评井及开发井测井曲线、地震解释成果、测井解释资料、试油试采动态开发数据研究整理的基础上,结合其断裂系统拆分结果,通过典型实例分析和油藏解剖得知,贝中油田南一段主力油层在“满凹含油”的基础上,形成含油性差区或水区的主要控制因素为:断层断失作用造成目的层内主力... 相似文献
1000.