中国南方风化磷块岩研究   总被引：3，自引：2，他引：3  

李铁生  文素秋 《化工矿产地质》1996,18(3):196-200

中国南方风化磷块岩中的风化磷矿的自然类型可分为两类七种型式，其中以“原位面型风化磷矿”和“位移溶洞砂砾磷矿”为主。风化磷矿是由其原矿的自身特性与外部适宜条件（水文地质条件为主导）综合作用的产物。根据碳酸盐、磷酸盐矿物分解、淋失程度可划分为弱风化、风化、强风化三个阶段。可用直接法、间接法和数学法３类共１３种方法加以判别  相似文献   

赤峰—朝阳地区金矿成矿物理化学条件研究     

刘纲 《黄金地质》1996,2(4):43-49

系统论述了区内各大类金矿的成矿温度，成矿压力，各种气体的逸度、ｐＨ值，金离子及其配合物的活度，讨论了金的迁移形式，推测了区内各类矿液中金的沉淀机制。  相似文献   

含金硫化物基岩区红土型金矿的成矿作用   总被引：8，自引：0，他引：8  

李志群 《矿产与地质》1996,10(6):380-387

实验表明，在含金硫化物基岩区，硫代硫酸金络阴离子团和硫酸金络阴离子团是金在表生条件下的主要迁移形式，它们的沉淀与铁、锰氢氧化物的形成有密切联系。金的表生迁移－沉淀条件除一般的表生地质条件外，还有特殊的物理化学－生物化学条件。络阴离子团的地球化学性质，控制着红土型金矿床的垂向分带与金的次生富集。  相似文献   

512铀矿床地浸条件及技术经济评价   总被引：2，自引：2，他引：2  

王保群 《铀矿地质》1997,13(3):147-153

本文应用铀矿普查及地浸试验中获取的资料，对５１２矿床地质构造、矿石物质成份、矿床水文地质、工程地质及自然经济地理等地浸条件及矿床技术经济条件进行了分析评价，认为５１２矿床地浸条件较好，地浸技术指标适中，用酸法地浸开采具有耗酸量少、成本低、经济效益好的特点。在今后的开采中，若能解决伴生元素Ｒｅ，Ｓｅ，Ｍｏ的综合利用问题，将会大大提高矿床的经济价值。  相似文献   

华北克拉通-扬子克拉通与秦岭造山带古地幔组成及状态的对比   总被引：4，自引：1，他引：4  

路凤香  郑建平  王方正  孙平  刘永顺  赵磊 《地球科学》1997,6(3)

经研究，华北克拉通古地幔以含石榴石的二辉橄榄岩、方辉橄榄岩及纯橄榄岩为主．地幔交代作用强烈，岩石富集不相容元素，明显高于南非及西澳克拉通者．扬子克拉通古地幔主元素亏损程度差，交代作用较弱，岩石为石榴石／尖晶石二辉橄榄岩．秦岭造山带壳、幔交界带的岩石类型复杂，包括蛇纹石化尖晶石二辉橄榄岩（蛇纹岩）、石榴石辉石岩、榴闪岩、变辉长岩及变玄武岩等．蛇纹岩遭受强的塑性流变，剪切变形结构发育．与克拉通相比，地幔交代作用很弱．３个地幔域的古地温状态有差异，秦岭造山带最高，扬子克拉通居中，华北克拉通最低．上述结果表明，两克拉通的古地幔特征相差显著，暗示经历了不同的演化过程．交代作用可能发生在１７００Ｍａ以前和１１００～５００Ｍａ，后者强于前者．造山带地幔的剪切变形明显强于克拉通地幔  相似文献   

A new form of the cokriging equations     

Andrew E. Long  Donald E. Myers 《Mathematical Geology》1997,29(5):685-703

Myers developed a matrix form of the cokriging equations, but one that entails the solution of a large system of linear equations. Large systems are troublesome because of memory requirements and a general increase in the matrix condition number. We transform Myers’s system into a set of smaller systems, whose solution gives the classical kriging results, and provides simultaneously a nested set of lower dimensional cokriging results. In the course of developing the new formulation we make an interesting link to the Cauchy-Schwarz condition for the invertibility of a system, and another to a simple situation of coregionalization. In addition, we proceed from these new equations to a linear approximation to the cokriging results in the event that the crossvariograms are small, allowing one to take advantage of a recent results of Xie and others which proceeds by diagonalizing the variogram matrix function over the lag classes.  相似文献   

Relocation of the October 9, 1505 Earthquake with M63/4     

Dong Ruishu  Xiang Hongfa  Guo Shunmin  Ran Hongliu  and Fu ChanghongInstitute of Geology  SSB  Beijing  China Institute of Geophysics  SSB  Beijing  China 《中国地震研究》1997,(4)

There have been 12 possible locations of the earthquakes occurring in the South Yellow Sea since 1505.In this paper,the location of the earthquake that occurred in 1505 has been determined by the collection of more historical data of the influenced field,referring the isoseismal data of earthquakes with the epicentral intensityⅨ and combining geophysical field data with tectonic condition,due to its great influence on seismic safety assessment of some significant engineering.  相似文献   

Study on simulation of spatial correlative earthquake ground motion field     

Xiao-Jun Li  Feng-Xin Zhao  Yu-Xian Hu 《地震学报(英文版)》1997,10(2):267-271

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Barotropic local instability and severe storm process     

Dasheng Yang  Lan Sun 《中国科学D辑(英文版)》1997,40(3):259-268

By means of barotropic model, the characteristic and initial value problems are investigated to reveal the local two-dimensional barotropic instability of the nonuniform current to the dynamic mechanism of the formation of the Yangtze-Huaihe River severe storm in July 1991. Analytical theory and numerical experiment show that (i) the unstable developing modes are chiefly the two periods of about 44 d and 10 d, which are fundamentally consistent with that of the precipitation change of the Yangtze-Huaihe River. (ii) The growth rate of the local perturbation is dominated by the meridional wave numbern = 1–5 and zonal wave numberk = 1–12, i.e. the severe storm over the Yangtze-Huaihe River results from the interaction of the systems at different latitudes and waves of different scales, (iii) The perturbation over the Yangtze-Huaihe River possesses the property of local intensification, which slowly migrates westward over the lower and middle reaches of the Yangtze-Huaihe River. (iv) The growth rate of the instability, especially the propagation velocity of the perturbation, is sensitive to the external parameters ū and α. Project supported by the National Natural Science Foundation of China.  相似文献   

流体在同心环状空间中流动时的压力损失     

张祝新  程晓新  夏圣强 《吉林大学学报(地球科学版)》1997,(2)

同心环状空间是工程上较常见到的流体流动空间，在此空间中流体流动情况的分析较复杂。工程上对其流动情况的分析常常是引用流体力学中的分析结果，但往往由于对环状空间结构的条件重视不够，引用时很容易出毛病。经过仔细推导分析，指出其应用条件，并有助于对同心环状空间中流体流动时压力损失的分析与计算  相似文献