Sedimentary and geochemical evidence of Eocene climate change in the Xining Basin,northeastern Tibetan Plateau

The northeastern Tibetan Plateau began to grow during the Eocene and it is important to understand the climatic history of Asia during this period of so-called ‘doubthouse' conditions. However, despite major advances in the last few decades,the evolutionary history and possible mechanisms of Eocene climate change in the northeastern Tibetan Plateau remain unclear.The Xining Basin in the northeastern Tibetan Plateau contains a continuous sequence of Early to Late Eocene non-marine sediments which provides the opportunity to resolve long-term climate changes during this period. In this study, we report the results of analyses of lithofacies, sediment color and geochemistry of bulk samples collected from the Xijigou section of the Xining Basin. An abrupt lithofacies change between the Early(~52–40 Ma) and Late Eocene(~40–34 Ma) indicates a change in the depositional environment from a shallow lake to a playa lake in response to a significant climatic shift. During ~52–40 Ma,higher values of sediment redness(a*), redness/lightness(a*/L*) and higher modified Chemical Index of Weathering(CIW′)indicate a relatively warm and humid climate, while from ~40–34 Ma the lower values of a*, a*/L*and lower CIW′ imply subhumid to semi-arid climatic conditions. The paleoclimatic records indicate a long-term(~52–34 Ma) trend of decreasing chemical weathering, consistent with global climate change. An abrupt sharp excursion of the proxy records during ~42–40 Ma suggests a relatively brief warm interval, corresponding to the Middle Eocene Climatic Optimum(MECO). We suggest that global cooling substantially reduced humidity in inner Asia, resulting in sub-humid to semi-arid climatic conditions after 40 Ma in the Xining Basin, which may have been responsible for the long-term trend of decreasing chemical weathering during the Eocene.     

中国石化枯竭气藏型储气库注采技术及发展建议

经长输管线输送的天然气注入到地下空间而形成的人工气藏称为地下储气库。国内外现有储气库大多数是枯竭气藏型地下储气库。中国石化储气库建设起步较晚,基础较为薄弱,同时与国内外已建成储气库相比,中石化储气库建设面临的地质条件和注采工况也较为复杂。以中国在建最大储气库项目中原文23储气库为例,其复杂地质条件以及面临的"快瞬变非稳态增压"注采难题需要进行专门研究。分析了目前中石化枯竭型气藏储气库建库现状,提出了建库技术挑战,总结了现阶段取得的注采关键技术研究成果,通过分析中国石化枯竭气藏型储气库注采技术研究现状和最新进展,提出了国产化技术完善、智能化注采营运、一体化模拟实验室的建设等方面的发展建议和要求,为持续加强规模化储气库群建设的支持提供参考。     

SPOT5遥感影像在土地调查中的应用

本文结合SPOT5卫星影像在某地区土地利用调查中的应用,介绍了利用SPOT5卫星遥感影像进行室内判读、结合外业调查建立土地利用数据库,进行土地利用调查的技术方法和工作流程。     

基于双正交小波的遥感图像融合研究

针对多光谱图像与全色图像融合中的光谱失真问题,采用一种双正交小波的方法进行融合。试验证明,该方法可以减少图像的失真问题,提高图像的空间分辨率,保留图像的边缘细节。     

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西昌盆地上三叠统白果湾组富有机质泥页岩沉积岩相古地理与孔隙特征

海陆过渡相富有机质泥页岩是页岩气勘查开发的重要领域。本文以西昌盆地上三叠统白果湾组富有机质泥页岩为研究对象,对研究区内富有机质泥页岩的沉积岩相古地理特征、微观孔隙类型、孔隙结构特征进行研究。白果湾组富有机质泥页岩段沉积相主要为湖泊相、三角洲相、河流相。发育不同类型的微孔隙,孔隙主要以小孔为主,微孔次之,平均孔径分布在5.56~56.89nm之间,比表面积平均为9.44m²/g,总孔体积平均为0.0187cm³/g。页岩气主要形成于滨浅湖亚相及半深湖亚相中,并主要吸附于富有机质泥页岩的小孔、微孔内;西昌盆地白果湾组富有机质泥页岩储集空间较好,具有良好的勘探潜力。     

赣南狮吼山硫铁多金属矿区花岗岩地球化学、年代学特征及其成因

狮吼山矿区是江西省内规模最大的矽卡岩型硫铁多金属矿床,伴生W、Cu、Au多种成矿元素,成矿作用与矿区出露的茶山迳复式花岗岩体有关。岩体主要包括茶山迳似斑状黑云母二长花岗岩和莲湖细粒二长花岗岩两期,为研究成矿岩体的侵位时代、岩石成因及与成矿的关系,本次工作进行了U-Pb锆石定年、岩相学和岩石地球化学等测试分析。结果表明：岩体具有高硅、高钾、富铝的特征,属高钾钙碱性系列花岗岩;轻重稀土元素分馏明显,均为右倾型,弱Eu负异常,以富集Cs、Rb、Th、U、Pb,亏损Ba、Nb、Sr、和Ti等元素为主要特征,属于低Ba-Sr壳源花岗岩类;锆石具较好晶形,具典型岩浆锆石特征,利用LA-ICP-MS进行U-Pb测年,获得谐和年龄为（162.4±0.6）Ma（MSWD=1.8）,加权平均年龄为（162.4±1.4）Ma（MSWD=1.4）,谐和年龄与加权平均年龄在误差范围内高度一致,表明茶山迳复式岩体侵位于燕山早期中侏罗世;综合考虑岩体矿物组合、主微量元素及高分异特征,认为其成因分类应属于S型花岗岩;对比中国花岗岩成矿元素平均含量,茶山迳两期花岗岩均具有较高的W、Mo、Bi、Pb等成矿元素含量,可同时为成矿作用提供热源、流体及物质。     

Discrete element modeling of transversely isotropic rocks with non-continuous planar fabrics under Brazilian test

Acta Geotechnica - A new numerical approach based on the particle discrete element method (PDEM) is developed to investigate the mechanical behavior of transversely isotropic rocks with...