茅台酒酿酒高梁的地质环境研究   总被引：2，自引：0，他引：2  

杨立铮  朱赫宇 《地学前缘》1996,3(2):224-233

茅台酒对酿酒高梁有严格要求，适于茅台酒传统酿造工艺的高梁只产于仁怀县的某些地区，主要是受地质环境的控制。仁怀高梁对某些常量和微量元素有着鲜明的选择性，对磷和钼表现出强烈的吸收作用。岩－土剖面元素的迁聚，对磷和铝的供应是确定仁怀高梁品质和产量的关键。侏罗系砂泥岩、二叠系煤系地层的岩－土剖面，元素淋溶微弱，总量丰富，有效态含量高，组合良好，能正常进行岩－土－高梁系统的物质转化与元素迁移，能充分供应高梁生长所需的磷和钼等元素，是茅台酒酿酒高梁的最宜种植区。  相似文献   

Comparison of the pseudo-static and dynamic behaviour of gravity retaining walls     

P. K. Woodward  D. V. Griffiths 《Geotechnical and Geological Engineering》1996,14(4):269-290

Summary Pseudo-static and dynamic non-linear finite element analyses have been performed to assess the dynamic behaviour of gravity retaining walls subjected to horizontal earthquake loading. In the pseudo-static analysis, the peak ground acceleration is converted into a pseudo-static inertia force and applied as a horizontal incremental gravity load. In the dynamic analysis, an actual measured earthquake acceleration time history has been scaled to provide peak ground acceleration values of 0.1 g and 0.3 g. Good agreement is obtained between the pseudo-static analysis and analytical methods for the calculation of the active coefficient of earth pressure. However, the results from the dynamic analysis require careful interpretation. In the pseudo-static analysis, the increase in the point of application of the resultant active force with the horizontal earthquake coefficient k _h from the one-third point to the mid-height of the wall is clearly observed. In the dynamic analysis, the variation in the point of application is shown to be a function of the type of wall deformation. Both finite element analyses indicate the importance of determining the magnitude of the predicted displacements when assessing the behaviour of the wall to seismic loading.  相似文献   

Characteristics and origin of sediment-hosted disseminated gold deposits: a review   总被引：4，自引：0，他引：4  

Greg B. Arehart 《Ore Geology Reviews》1996,11(6):383-403

Sediment-hosted disseminated gold (SHDG) deposits comprise a major portion of the gold production and reserves in the US. Although presently known to be common only in western North America, SHDG deposits are a significant source of world gold production. These deposits are characterized by extremely fine-grained disseminated gold, hosted primarily by arsenian pyrite. Other metals show very little enrichment although in addition to As, anomalous concentrations of elements such as Sb, Hg, Tl and Ba are utilized as exploration tools. The host rocks are dominantly silty carbonates, but ore concentrations are also present in siliceous and silicified rocks as well as intrusive rocks. Alteration consists of decarbonatization, silicification (jasperoid formation) and argillization, which are arranged both spatially and temporally in that order. Argillic alteration is zoned from kaolinite-dominated cores to sericite-dominated margins. The deposits commonly exhibit significant structural (faults) and stratigraphic (composition/permeability) controls. Until the last few years, SHDG deposits were considered as near-surface, epithermal type deposits in origin. Because of their fine-grained nature and the lack of macroscopic features such as veins, it has proven quite difficult to extract geochemical data that are clearly related to their genesis. However, fluid inclusion data indicate pressures corresponding to depths of 2–4 km under lithostatic conditions. Temperatures are constrained by fluid inclusions and phase equilibria to near 225°C. Stable isotope data from alteration minerals and fluid inclusions indicate that the ore fluids were dominated by meteoric waters, some of which had clearly exchanged oxygen with wallrocks during their passage through the crust. Although the data vary, most ore fluids probably had δD values near −150‰ and δ¹⁸O values ranging from −10 to +5‰. Sulfur isotope values reported from SHDG deposits span a wide range, from −30 to +20‰ (sulfides) and 0 to >45‰ (sulfates). Ore-related sulfides (pyrite, realgar) fall at the upper end of the range reported for sulfides. The alteration and mineral assemblage indicate the ore fluids were probably near neutral and gold was likely carried as a bisulfide complex. The depositional mechanism(s) probably included mixing, cooling and oxidation. These mechanisms are consistent with the observed alteration features, i.e. quartz precipitation, calcite dissolution and sericite-kaolinite coexistence. It also explains the presence of both siliceous ores containing native Au and sulfide ores containing Au in pyrite. The extreme variations in sulfur isotopes as seen at Post and fluid inclusion data from Carlin may be indicative of some phase separation (‘boiling’), but such relations have not been documented in other deposits and the importance of phase separation to gold deposition appears minimal.  相似文献   

MD－50型钻机液压系统的设计          下载免费PDF全文

于飞 《探矿工程》1996,(2):47-48

介绍了ＭＤ－５０型钻机液压系统的设计原理和主要液压元件的选择依据，并通过对设计和实践的总结，谈了作者在全液压钻机液压系统设计中的一些体会。  相似文献   

垂直断层附近三维不均匀体点源电场的边界单元法     

李予国  徐世浙 《物探化探计算技术》1996,18(2):147-151

本文将给出垂直断层附近三维不均匀体电阻率法的数值解，所用方法是边界单元法，但基本解的选择与以往的边界单元法不同。  相似文献   

多媒体创作工具Compel的应用     

徐晓平  陈天与 《物探化探计算技术》1996,18(4):325-330

本文介绍了一种多媒体应用的创作工具。利用这种工具可以编辑和组织文字、图象、图表、声音以及视频等多种媒体元素。并通过媒体链接以及超级链接，完成多媒体应用的制作。同时，也介绍了多媒体应用的播放。  相似文献   

Geochemistry of the Jinman Vein—Type Copper Deposit,Western Yunnan Province,China——I.Element Geochemical Characteristics   总被引：3，自引：0，他引：3  

季宏兵  李朝阳 《中国地球化学学报》1996,15(2):172-184

The Jinman copper deposit,which is situated on the northern margin of the Lanping-Simao back-arc basin,western Yunnan Province,is a silver-bearing,high-grade vein-type copper deposit.Comprehensive element geochemical studies of the host rocks and hydrothermal minerals revealed the regularities in the distribution,mobilization and transport of elements from the host rocks to hydrothermal minerals.In conjunction with the fluid inclusion and isotope data,it is suggested that the ore-forming fluid was derived mainly from a deep source characterized by CO2 enrichment and reduction in nature.It is also suggested that the oreforming materials come largely from a deep source.although the contribution of the country rocks should not be ruled out.It is also found that some hydrothermal minerals are possessed of MREE-enrichment patterns.It is deduced that the REEs in the deep-source ore fluid were transported in the form of CO3^2- complexes and were deposited in a continental basin(or a hot-spring basin).  相似文献   

A Study on the Geological—Geochemical Dynamics of Hydrothermal Ore Deposition as Exemplified by the Muping—Rushan Gold Deposit Belt,Eastern Shandong,China     

赵伦山  高太忠等 《中国地球化学学报》1996,15(4):289-295

This paper presents a method of establishing a hydrothermal ore-forming reaction system.On the basis of the study of four typical hydrothermal deposits,the following conclusions concerning geochemical dynamic controlling during hydrothermal mineralization have been sions concerning geochemical dynaamic controlling during hydrothermal mineralization have been drawn:(1)The regional tectonic activities control the concentration and dispersion of elements in the ore-forming process in terms of their effects on the thermodynamic nature and conditions of the ore-forming reaction system.(2)During hydrothermal mineralization the activites of ore-bearing faults can be divideb into two stages:the brittle splitting stage and the brittle-tough tensing stage,which would create characteristically different geodynamic conditions for the geochemical thermodynamic ore-forming system.(3)The hydrothermal ore-forming reaaction system is an open dynamic system.At the brittle splitting stage the system was so strongly supersaturated and unequilibrated as to speed up and enhance the crystallization and differentiation of ore-forming fluids.And at the brittle-tough tensing stage,the ore-forming system was in a weak supersaturated state;with decreasing temperature and pressure the crystallization of oreforming material would show down,and it can be regarded as an equilibrated state.(4)In the lates stages of hydrothermal evolution,gold would be concentrated in the residual ore-forming solution.The pulsating fracture activite in this stage led to the crush of pyrite ore and it was then filled with gold-enriched solution,forming high-grage“fissure”gold ore.This ore-forming process could be called the coupling mechanism of ore formation.  相似文献   

地幔交代作用的微区微量元素证据——云南双沟蛇绿岩的质子探针研究   总被引：2，自引：0，他引：2       下载免费PDF全文

张旗  陈龙红 《地质科学》1997,32(1):88-95

用质子探针技术对双沟地幔交代熔融物的微区微量元素进行了测定。研究表明,地幔橄榄岩中的残留矿物橄榄石和斜方辉石仅含Ni和Zn,而Ga、Ge、Sr、Rb、Zr、Y、As、Pb等微量元素主要集中在地幔部分熔融所产生的矿物(尤其是尖晶石和绿泥石)中。微区范围内微量元素的分布表明,尖晶石二辉橄榄岩地幔不均一性的尺度可达微米级,通常解释为尖晶石二辉橄榄岩在开放系统下地幔交代作用的结果。  相似文献   

深层搅拌桩复合地基的有限元分析   总被引：18，自引：3，他引：18  

周建民  丰定祥 《岩土力学》1997,18(2):44-50

介绍了用自行编制的适用于群桩地基基础应力、变形分析的三维非线性程序对一种有代表性的群桩进行分析的情况。讨论了深层搅拌桩复合地基的工作机制和应力、变形分布特点，并通过多种方案的比较就不同的荷载水平、桩长、桩上置换率、土层分布、桩身变形模量等诸因素对地基沉降、桩端应力、桩的承载率的影响和规律进行了研究。  相似文献