地洼区的过渡间成矿及其意义──以东南地洼区铀矿为例     

陈勤五 《大地构造与成矿学》1999,23(4):293-299

本文以东南地洼区铀矿为例,对过渡层（岩性）、构造过渡带及地洼阶段过渡期的有利配合的“三位一体”的成矿模式进行阐述,并对其找矿意义进行了初步探讨。  相似文献   

Stable channel analysis with sediment transport for rivers in Malaysia: A case study of the Muda,Kurau, and Langat rivers     

《国际泥沙研究》2020,35(5):455-466

Assessments of a stable channel were done to evaluate the conditions of three rivers in Malaysia, using an analytical method that modifies the stable channel flowchart developed by Chang (1988) and Ariffin (2004). The analytical approach was selected to calculate the suitable dimensions for a stable channel, using equations that describe the physical relation of sediment transport, flow resistance, and dynamic equilibrium. Measured field data were used as the input data for the stable channel program, which then processed the data until the input discharge was equal to the output discharge. However, this method depends on the accuracy of the sediment transport equation that is used in the stable channel design. Existing equations recommended by the Department of Irrigation and Drainage (DID), Malaysia, were found to be unsuitable because of their low discrepancy ratio (DR) values, which were below 42%. These are the equations of Engelund and Hansen (1967) and Yang (1979), as well as existing local equations from Ariffin (2004) and Sinnakaudan et al. (2006). Therefore, revised equations were developed in the current study to increase the accuracy of the total bed material load equations for use in Malaysian rivers. The newly revised Ariffin (2004) and Sinnakaudan et al. (2006) equations yielded better DRs of 66.34 and 64.49%, respectively. River assessments done on the Kurau River (a small river), the Muda River (a medium-size river), and the Langat River (a large river) show that these rivers have experienced different levels of erosion. Only the Kurau River was found to have minimal erosion and sedimentation levels. Conversely, stable channel assessments for the Muda River and the Langat River revealed that both rivers had experienced severe erosion, due to excessive sand mining. Almost all the cross section sampling points on the Muda River and Langat River were deeper than the suggested stable channel heights.  相似文献   

新疆西天山莫托萨拉热水沉积型铁锰矿床矿物学与地球化学特征     

董志国  张帮禄  石方平  张连昌  高炳宇  张新  彭自栋  王长乐 《岩石学报》2021,37(4):1099-1121

莫托萨拉铁锰矿床位于西天山阿吾拉勒成矿带东端,研究程度相对薄弱,在矿床成因方面存在热水沉积、沉积-热液改造、胶体化学沉积等争论。本文详细研究了莫托萨拉最上层锰矿及其围岩的矿物组成、结构构造和地球化学特征,并综合前人资料对整个铁锰矿床的成因做了进一步探讨。本研究首次在矿区发现了热液长石岩,其主要由钠长石、钾长石以及少量重晶石、霓石、锌铁黄长石等矿物组成,类似于"白烟型"热水沉积岩。莫托萨拉最上层锰矿主要由锰橄榄石、褐锰矿、红硅锰矿、磁锰铁矿以及少量重晶石、方铁锰矿等矿物组成,发育有典型的热水内碎屑结构,指示其沉积于海底热液喷流口附近。该层锰矿的Al/(Al+Fe+Mn)值很低(0～0.02)、Si/Al值较高(7.9～10.9)、Fe/Ti值很高(428～1353),通过UCC标准化后发现明显富集Zn、Ba、Pb等元素,而Co、Ni、Cu等元素未见富集,以上地球化学特征与现代海底热液成因铁锰沉积物一致。在Fe/Ti-Al/(Al+Fe+Mn)、Si O2-Al2O3、10×(Co+Ni+Cu)-Fe-Mn、100×(Zr+Ce+Y)-15×(Cu+Ni)-(Fe+Mn)/4等判别图中,莫托萨拉的锰矿层和铁矿层样品均落在海底热液沉积区。锰矿层和铁矿层的稀土元素经PAAS标准化后具有明显的Ce负异常、Eu正异常和Y正异常,与现代海底热液成因铁锰沉积物的稀土配分模式非常相似。综合分析本次研究的矿物学、岩石学、地球化学特征以及前人资料,本文认为莫托萨拉铁锰矿床为海相热水沉积成因,成矿与同期海底火山的间歇性活动密切相关,海底热液的化学组分、温度高低和活动强弱都具有明显的脉动性。莫托萨拉矿区铁锰共存但各自独立成矿,且铁锰分离程度较高,这在显生宙沉积型锰矿中独具特色。鉴于前人曾报道莫托萨拉铁矿石中存在菌藻类微生物化石,我们推测,该矿床的铁锰分离过程除了受控于沉积环境的氧化还原条件变化外,微生物的选择性氧化沉淀可能也发挥了重要作用,值得开展深入研究。  相似文献   

The solution of the long-wave equation for various nonlinear depth and breadth profiles in the power-law form     

《Dynamics of Atmospheres and Oceans》2021

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A casting procedure for reproducing coarse‐grained sedimentary surfaces     

Thomas Buffin‐Blanger  Ian Reid  Stephen Rice  Jim H. Chandler  Jill Lancaster 《地球表面变化过程与地形》2003,28(7):787-796

In the ?eld, the measurement of near‐bed hydraulics remains problematic. Greater precision is possible in the laboratory, but, in the case of gravels, it is dif?cult to create a water‐worked channel‐bed that is realistic enough to replicate faithfully the conditions found in nature. In this paper, a technique to reproduce coarse‐grained sedimentary fabrics of large areal extent is described. It involves moulding natural river‐bed surfaces from which facsimiles are cast. Remarkably realistic casts with dimensions of 1 m by 2 m have been produced and their quality assessed using spatial data derived using automated digital photogrammetry. The casts reproduce the prototype surfaces with errors at millimetre scale (0·5 per cent of the microrelief). The technique has facilitated the introduction of sedimentary surfaces that incorporate natural, complex structures of grains up to cobble size into experimental channels where detailed studies of near‐bed hydraulics can be carried out. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

石油物探软件项目管理应用信息平台的开发     

姚秋明  岳承祺 《物探化探计算技术》2003,25(4):317-322

介绍了基于企业局域网的石油物探软件项目管理应用信息平台的开发，开发应用信息平台的需求分析、信息平台的设计、项目管理表单模板以及信息平台数据库的建设。详细介绍了建设背景和信息平台的环境建设，以及对信息平台内容作了较详细的分析，特别是表单模板设计的有关内容，包括项目实施计划、软件测试计划、软件维护计划等。  相似文献   

关于全球通地理信息系统的思考   总被引：6，自引：0，他引：6  

龚强 《测绘科学》2003,28(3):74-76

由多数据格式组成的多源数据非常复杂,主要表现在没有标准的基础数据,旧有的数据又难以利用,数据的多语义性,获取数据方法的多源性,数据存储格式的多样性以及数据的多时空性和多尺度等,但多源数据集成共享又是客观需要。目前的多源数据集成有数据格式转换模式、数据互操作模式和直接数据访问模式,以上几种模式虽各具千秋,却各有不足,解决的办法只有建立全球通地理信息系统,以实现各系统技术原则统一,交流沟通顺畅,实现真正意义的共享。因此,建立全球通地理信息系统势在必行。  相似文献   

The accuracy of a river bed moulding/casting system and the effectiveness of a low-cost digital camera for recording river bed fabric     

Jim H. Chandler  Tom Buffin-Bélanger  Steve Rice  Ian Reid  David J. Graham 《The Photogrammetric Record》2003,18(103):209-223

Digital photogrammetry has been used to develop and test an artificial river bed moulding and casting system, which allows the pebbles within a coarse-grain river bed to be recreated for hydraulic research in a laboratory flow channel or flume. Imagery of both the original streambed and the cast facsimile was acquired using a non-metric Kodak DCS460 digital camera and digital elevation models and orthophotographs were derived and compared to assess the accuracy of the moulding and casting system. These comparative tests proved to be critical in modifying and developing the system.
Additional imagery was obtained in the field using a non-metric Olympus C3030 'compact' digital camera to assess whether far cheaper camera technology could deliver data appropriate for such comparative examinations. Internal calibration parameter sets and data that were generated were compared with data obtained by the non-metric Kodak DCS460. These tests demonstrate that digital sensors built around high-quality 35 mm professional camera bodies and lenses are required for comparative examinations and for similar system development.  相似文献   

贵州盘县地区峨眉山玄武岩铜矿的成矿地质条件   总被引：12，自引：0，他引：12  

刘远辉李进  邓克勇 《地质通报》2003,22(9):713-717

以峨眉山玄武岩底部与中二叠统茅口组灰岩接触界面上赋存的黄见坑-哈树富铜矿带为例，论述了这一新类型玄武岩铜矿的成矿地质条件及峨眉山玄武岩浆喷-溢对Cu(Au、Pb、zn、Pt、Pd、Sb、F等)元素的富集和后期热液改造成矿作用，以扩大找矿思路。  相似文献   

GPS整周模糊度确认中残差二次型次小与最小之差的分布问题     

周世健  臧德彦等 《测绘学院学报》2002,19(1):5-7,10

根据残差二次型次小与最小之差进行整周模糊角度确认的关键是差值的分布，只有得到了合理的差值分布才可确定合理的界值。文中基于原有的两种方法及这两方法的不足，从理论上导出了满足条件的差值分布，并作了一定的说明。  相似文献