粘土矿物的提取、鉴定及其古气候意义——以柴达木盆地怀头他拉剖面为例          下载免费PDF全文

鲍晶  叶程程  栗兵帅 《干旱区地理》2022,45(3):814-825

沉积物中粘土矿物类型主要有自生粘土矿物和碎屑粘土矿物。其中,自生粘土矿物含量较少,是在沉积环境中形成,可能是沉积再循环或成岩作用的产物,可作为沉积环境某方面的指示标志;而碎屑粘土矿物是母岩风化的产物,受沉积环境影响较小,能够有效示踪物源区化学风化过程,进而反映古气候变化。近年来利用碎屑粘土矿物特征来重建物源区古气候的方法得到了广泛的应用。然而,由于粘土矿物主要存在于<2 μm硅酸盐粘粒中,粘土矿物的提取、鉴定比较困难,且自生粘土矿物易受沉积环境等的影响。因此,在利用粘土矿物重建古气候变化时,需慎重选择粘土矿物的提取方法,并考虑物源和沉积环境变化以及成岩作用等对粘土矿物解释的影响。本文以柴达木盆地东北缘怀头他拉剖面硅酸盐粘土矿物的提取、鉴定及其古环境指示意义为例,介绍粘土矿物的提取及应用,为后期粘土矿物研究提供参考。  相似文献   

新疆塔额盆地各气象要素对水面蒸发影响的敏感性分析     

魏光辉 《沙漠与绿洲气象(新疆气象)》2014,8(5):44-47

水面蒸发敏感因素的判断,对于干旱区水资源的规划与利用具有重要指导意义。文章以新疆塔额盆地内的塔城市气象站1981—2010年资料为例,采用敏感系数法对研究区多年月均水面蒸发影响因素进行敏感性分析,并与关联分析法分析的结果对比。结果表明：在塔额盆地内,温度与水汽压二因素对水面蒸发影响最为敏感;基于敏感系数法的敏感因素研究结果与关联分析的结果基本一致,尤其在主要影响因子的判定上。  相似文献   

兰州地区降水量正态分布特征     

白冰  陆登荣  陈学君  韩海涛  王有恒 《干旱气象》2014,(1):123-127

在对降水资料的分析过程中,要求资料的时间序列呈正态分布。利用兰州地区的兰州、皋兰、榆中和永登4个站点1960~2009年的降水量资料,采用"偏度—峰度系数+W检验"方法,基于SPSS软件,对兰州地区的年、季和月降水量正态特征进行分析。结果表明,兰州地区4个气象站的年降水量均呈正态性分布;兰州、皋兰和永登3站的夏、秋2季降水量为正态性分布,而榆中站只有秋季降水量为正态性分布,且秋季降水量的正态性最好,冬季最差;大多数月降水量不服从正态分布,但对降水序列进行平方根处理后,其正态性得到明显的改善。  相似文献   

Improved understanding of petroleum migration history in the Hongche fault zone,northwestern Junggar Basin (northwest China): Constrained by vein-calcite fluid inclusions and trace elements   总被引：1，自引：0，他引：1  

Jian Cao  Zhijun Jin  Wenxuan Hu  Yijie Zhang  Suping Yao  Xulong Wang  Yueqian Zhang  Yong Tang 《Marine and Petroleum Geology》2010

Calcite veins and cements occur widely in Carboniferous and Permian reservoirs of the Hongche fault zone, northwestern Junggar Basin in northwest China. The calcites were investigated by fluid inclusion and trace-element analyses, providing an improved understanding of the petroleum migration history. It is indicated that the Hongche fault behaved as a migration pathway before the Early Cretaceous, allowing two oil charges to migrate into the hanging-wall, fault-core and footwall reservoirs across the fault. Since the Late Cretaceous, the Hongche fault has been sealed. As a consequence, meteoric water flowed down only into the hanging-wall and fault-core reservoirs. The meteoric-water incursion is likely an important cause for degradation of reservoir oils. In contrast, the footwall reservoirs received gas charge (the third hydrocarbon event) following the Late Cretaceous. This helps explain the distribution of petroleum across the fault. This study provides an example of how a fault may evolve as pathway and seal over time, and how reservoir diagenetic minerals can provide clues to complex petroleum migration histories.  相似文献   

Fossilisation of a silica diagenesis reaction front on the mid-Norwegian margin     

Raluca Cristina Neagu  Joe Cartwright  Richard Davies  Lars Jensen 《Marine and Petroleum Geology》2010

The diagenetic transformation of biogenic silica from opal-A to opal-CT was recognised on seismic reflection data over an area of 78 × 10³ km² on the mid-Norwegian margin. The opal-A/CT diagenetic boundary appears as a positive, high amplitude reflection that generally cross-cuts the hosting stratigraphy. We demonstrate that it is not a sea bottom simulating reflection (BSR) and also that is not in thermal equilibrium with the present day isotherms. We present arguments that three styles of deformation associated with the opal-A/CT reflection – polygonal faulting, regional anticlines and synclines and differential compaction folding – indicate that the silica diagenesis reaction front is fossilised at a regional scale. Isochore maps demonstrate the degree of conformity between the opal-A/CT reflection and three seismic horizons of Late Miocene to Early Pliocene age that potentially represent the paleo-seabed when ‘fossilisation’ of the reaction front took place. The seismic interpretational criteria for recognition of a fossilised diagenetic front are evaluated and the results of our study are integrated with previous studies from other basins of the NE Atlantic in order to determine if the arrest of silica diagenesis was diachronous along this continental margin.  相似文献   

四川盆地汛期旱涝预测研究     

马振锋 《成都信息工程学院学报》1999,(1)

对近１０年来四川盆地汛期降水预测水平进行了定量评估，并与国家气候中心预测水平作了对比。在分析影响四川盆地汛期降水主要物理因素的基础上，提出了四川盆地汛期旱涝预测的基本思路和技术方法，并在实际业务预报中取得了较好的效果。  相似文献   

The Basin of Mexico and its metropolitan area: water abstraction and related environmental problems     

T. Gonzlez-Morn  R. Rodríguez  S. A. Cortes 《Journal of South American Earth Sciences》1999,12(6):431

The Basin of Mexico is a closed basin of lacustrine character, with an average elevation of 2200 m above sea level. The watershed covers a vast extension in five states. Mexico City and its metropolitan area are located within this basin. The aquifer system is the main source of water supply for more than 20 million people. Water consumption is about 60 m³/s. The aquifer supplies about 43 m³/s from around 1000 wells at 70–200 m depth. Pumping policies have generated subsidence and degradation of the ground water quality in the Basin of Mexico The lacustrian clay layers play an important role in the local hydrogeology, protecting the aquifer from pollution, but the transition and piedmont areas are highly vulnerable to surface pollutants.  相似文献   

黄河流域人地耦合与可持续人居环境   总被引：2，自引：2，他引：2  

汪芳  安黎哲  党安荣  韩建业  苗长虹  王静  张广汉  赵勇 《地理研究》2020,39(8):1707-1724

黄河流域是中国人地矛盾最为紧张的区域之一,承担着生态安全建设和经济社会发展的重任。自古以来人类和黄河始终处于共同进化的过程中,近年来伴随经济发展而来的生态保护压力也日益增加,流域水资源脆弱性和风险更甚,为化解人地矛盾,需探究城镇聚落和河流的动态耦合机制。在“黄河流域生态保护和高质量发展”上升为重大国家战略之际,从城乡规划、自然地理、环境考古、生态学、水文水资源、土地资源管理等多领域视角,聚焦黄河流域人地关系的空间分异和演化规律,以及资源和生态保护的困境与机遇。建成环境与自然环境的平衡是可持续发展的基础,应将黄河流域视为自然及人文环境相互影响与依存的“生命共同体”,并从系统性和交叉性、地方性和适应性等方面探讨可持续发展策略。  相似文献   

Tertiary coal geology and stratigraphy of the Port Phillip Basin,Victoria     

G. R. Holdgate  S. J. Gallagher  M. W. Wallace 《Australian Journal of Earth Sciences》2013,60(3):437-453

Results from coal‐exploration drilling in the onshore part of the Port Phillip Basin, Victoria, have established stratigraphic and age correlations of the Lower Miocene Werribee Formation brown coal deposits at Bacchus Marsh to similar brown coals at Altona. The coal deposits occur in a northwest‐southeast structural depression (the Parwan Trough) that appears to be a southeast continuation of the Ballan Graben. Recent drilling for potential coal‐bed methane in the trough has provided new data on the deeper stratigraphy not penetrated by earlier drilling, including recognition of an Upper Cretaceous to Eocene Yaloak Formation coal‐bearing interval, similar to the Anglesea area, Ballan Graben and Lal Lal Basin. Up to 200 m of coal‐bearing sediment and minor volcanics underlie the Miocene coal measures. A marine facies transition takes place between the Miocene coal swamps of the Parwan Trough, through barrier sands west of Werribee, to carbonate facies near Geelong. To the south beneath Port Phillip Bay, a similar transition probably occurs between coal swamps of the Parwan Trough and fully marine carbonate environments of the contiguous Sorrento Graben. The palaeogeographical reconstructions suggest a similar coal‐to‐carbonate facies transition as in the adjacent onshore Gippsland Basin.  相似文献   

Neoproterozoic (Cryogenian) stromatolites from the Wolfe Basin,east Kimberley,Western Australia: Correlation with the Centralian Superbasin     

K. Grey  D. H. Blake 《Australian Journal of Earth Sciences》2013,60(3):329-341

Linella avis, an early to middle Neoproterozoic (Tonian to Cryogenian) stromatolite, occurs in the Eliot Range Dolomite, part of the Ruby Plains Group in the Wolfe Basin, east Kimberley. Previously, this dolomite was assigned to the Mesoproterozoic Bungle Bungle Dolomite in the Osmond Basin, which contains a different suite of stromatolites. Linella avis, which also occurs in the Neoproterozoic Bitter Springs Formation of the Amadeus Basin, central Australia, appears to be restricted to rocks aged around 850 to 800 Ma. The presence of L. avis indicates that the Ruby Plains Group is a probable correlative of the Heavitree Quartzite and Bitter Springs Formation, and is probably much younger than the Bungle Bungle Dolomite. If the correlation suggested here is correct, the Wolfe Basin, together with the Amadeus and Ngalia Basins, formed part of the Centralian Superbasin.  相似文献