老挝龙湖钾盐矿床沉积碳酸盐碳、氧同位素组成及其对成钾环境的初步指示

碳、氧同位素作为反映古沉积环境、成矿物源和水–岩反应等良好的稳定同位素指标,被广泛应用。通过对老挝龙湖钾盐矿区ZK309、ZK301、ZK311和ZK004四个钻孔农波组盐岩上覆泥岩碳、氧同位素组成的分析,讨论了盐岩上覆泥岩沉积的碳、氧同位素组成变化特征及其指示的沉积环境。经分析,所测碳、氧同位素基本代表了碳酸盐碳、氧同位素组成,初步推测这些碳酸盐均为当地自生,受后期改变很少,δ13C和δ18O平均值分别为-5.1‰和-4.6‰,其中δ13C值略高于一般陆相碳酸盐碳同位素最大值–5.69‰,δ18O值介于–2.71‰~–10.8‰之间,ZK309和ZK301钻孔碳、氧同位素相关系数均小于0.7,初步指示盐岩沉积之后沉积环境为陆相。δ13C值略高于–5.69‰,推测是后期盐岩层被淋滤,泥岩层受淋滤后的残余卤水影响的结果,这也解释了蒸发岩沉积层序异常(钾石盐覆盖于光卤石之上)的沉积特征。因此,在本研究中,大气水在泥岩碳、氧同位素的变化中扮演了重要角色。     

峨眉山大火成岩省太和花岗岩的成因及构造意义

攀西地区的太和花岗质岩体和赋存超大型钒钛磁铁矿矿床的辉长岩体在空间上共生,成因上均与峨眉山地幔柱头的上升密切相关.太和花岗质岩体主要由超碱质花岗岩和石英正长岩及少量正长岩组成;富含高场强元素并具高Ga/Al值(3.74～5.63),显示典型A型花岗岩的特征.花岗岩、正长岩和辉长岩的Nb/Ta和Zr/Hf值与洋岛玄武岩(OIB)的相应比值近似.花岗质岩石具较低的87Sr/86Sr初始值(0.7025～0.7049)和正的εNd(t)值(1.9～3.5),与辉长岩的值相近[(87Sr/86Sr)i =0.7049～0.7052; εNd(t) =2.4～3.3].太和花岗质岩体的εNd(t)为正值,显示地幔柱来源的底侵玄武质岩浆对其形成起主要作用.辉长质和花岗质岩石具相似的钕同位素组成,表明其母岩浆来自于同一源区.我们认为太和花岗质侵入体主要由底侵于下地壳的玄武质岩浆分异出的花岗质熔体侵位及随后经结晶分异而形成.因此,晚古生代时幔源岩浆底侵造成的地壳增生在峨眉山大火成岩省中表现极为显著.     

元谋干热河谷坡耕地土壤侵蚀造成的土地退化

在元谋干热河谷土壤侵蚀特征分析的基础上，对坡耕地土壤侵蚀造成的土地退化进行了模拟研究。结果表明，土壤侵蚀造成表层耕作土壤的物理性能下降、养分流失和水分入渗能力降低。表层耕作土壤的容重比下层土壤低12．7％，总孔隙度高10．9％，有机质高37．3％，120min累计入渗总量是下层土壤的1．6-2．2倍。模拟土壤侵蚀与土地生产力关系的小区试验结果显示，坡耕地每流失1cm表土，土地生产力水平平均下降4．54％。     

FY-3E: The First Operational Meteorological Satellite Mission in an Early Morning Orbit

Fengyun-3 E(FY-3E),the world’s first early-morning-orbit meteorological satellite for civil use,was launched successfully at the Jiuquan Satellite Launch Center on 5 July 2021.The FY-3E satellite will fill the vacancy of the global early-morning-orbit satellite observation,working together with the FY-3C and FY-3D satellites to achieve the data coverage of early morning,morning,and afternoon orbits.The combination of these three satellites will provide global data coverage for numerical weather prediction(NWP)at 6-hour intervals,effectively improving the accuracy and time efficiency of global NWP,which is of great significance to perfect the global earth observing system.In this article,the background and meteorological requirements for the early-morning-orbit satellite are reviewed,and the specifications of the FY-3E satellite,as well as the characteristics of the onboard instrumentation for earth observations,are also introduced.In addition,the ground segment and the retrieved geophysical products are also presented.It is believed that the NWP communities will significantly benefit from an optimal temporal distribution of observations provided by the early morning,mid-morning,and afternoon satellite missions.Further benefits are expected in numerous applications such as the monitoring of severe weather/climate events,the development of improved sampling designs of the diurnal cycle for accurate climate data records,more efficient monitoring of air quality by thermal infrared remote sensing,and the quasicontinuous monitoring of the sun for space weather and climate.     

四川龙门山地区早中泥盆世孢子化石研究

本文系统研究了四川龙门山地区下泥盆统桂溪组、木耳厂组、观音庙组、关山坡组以及中泥盆统金宝石组的孢子化石,共鉴定孢子41属81种,建立了三个孢子组合带,由下至上分别是:Retusotriletes rotundus—Calamospora panucea(RP)孢子组合、Synorisporites downtoensis—Verrucosisporites scurrus(DS)孢子组合、Densosporites inaequus—Grandispora inculta(Ⅱ)孢子组合。通过与研究较为详细的西欧、北美地区的经典资料,包括老红砂岩大陆、北欧、加拿大等地区,以及国内相关资料的对比,结合特征种的地层分布、重要属种的含量、孢子大小等组合特征,确定RP组合时代为Lochkovian,DS组合时代为Pragian至早Emsian,Ⅱ组合时代为Eifelian中晚期—Givetian早期。这也是首次在金宝石组中发现孢子化石并对其进行研究。另外,通过对孢子直径的统计分析从另一个角度探讨了古植物的演化历程。     

盾构隧道施工地表变形分析与三维有限元模拟

随着地表建、构筑物密度与日俱增,在地铁建造过程中对地表环境的保护是一个越来越不容忽视的难题。盾构法隧道施工技术成功地应用于地铁施工之后,如何合理预测和控制盾构施工对地表变形的影响就成为了一个新课题。在查阅大量文献的基础上,总结前人的计算方法,利用有限元方法对某盾构隧道工程进行了三维的变形模拟分析,与实测的数据比较计算结果较为满意。     

安徽宣城黄土堆积的磁性地层学与古环境意义

利用磁性地层学方法对安徽宣城剖面的研究表明,B/M界限位于剖面中网纹红土的中下部,结合光释光测年可以外推出长江中下游地区的典型风成沉积开始形成于0.85Ma前后。这一年龄对应于一次全球性的气候转型事件,在海洋沉积与我国北方的黄土-古土壤序列中均记录了这一气候转型事件。同时,0.85Ma对应于中更新世的两大地质事件,一是全球冰量的增加,二是青藏高原的快速隆升,长江中下游地区风成堆积的开始,可能是上述两个因素共同作用的结果。      

The 2020/21 Extremely Cold Winter in China Influenced by the Synergistic Effect of La Niña and Warm Arctic

In the first half of winter 2020/21,China has experienced an extremely cold period across both northern and southern regions,with record-breaking low temperatures set in many stations of China.Meanwhile,a moderate La Ni?a event which exceeded both oceanic and atmospheric thresholds began in August 2020 and in a few months developed into its mature phase,just prior to the 2020/21 winter.In this report,the mid?high-latitude large-scale atmospheric circulation anomalies in the Northern Hemisphere,which were forced by the negative phase of Arctic Oscillation,a strengthened Siberian High,an intensified Ural High and a deepened East Asian Trough,are considered to be the direct reason for the frequent cold surges in winter 2020/21.At the same time,the synergistic effect of the warm Arctic and the cold tropical Pacific(La Ni?a)provided an indispensable background,at a hemispheric scale,to intensify the atmospheric circulation anomalies in middle-to-high latitudes.In the end,a most recent La Ni?a prediction is provided and the on-coming evolution of climate is discussed for the remaining part of the 2020/21 winter for the purpose of future decision-making and early warning.     

黄河口凹陷流体包裹体成藏年代和充注期次研究

流体包裹体技术已被证实在含油气盆地的成藏年代和运移期次的研究中是一个有效的手段。关于包裹体在成藏期次方面的研究已有许多,但系统介绍包裹体技术在油气勘探中的应用研究则少见。为推动该方法在油气勘探中的应用,本文从样品制备、分析仪器、流体包裹体镜下特征、均一温度等方面系统介绍了利用流体包裹体确定油气成藏年代与充注期次的方法,以及该方法在黄河口凹陷油气勘查中的应用研究成果:确定了该凹陷普遍发育较低成熟液态烃包裹体、成熟气液态烃包裹体、较高成熟气液态烃包裹体和气烃包裹体3类包裹体,确定了黄河口地区沙河街组油气充注至少有3期:第1期、第2期油气于明化镇组沉积时期开始注入储层(10~5Ma),第3期较高成熟油及伴生气于第四纪开始注入储层(小于3Ma);利用包裹体均一温度还确定了位于黄河口凹陷与渤中凹陷交界的BZ25构造第1期油气来源于渤中凹陷。     

东川铜矿硅质角砾40Ar-39Ar定年探讨

为探索热液成因含微量钾矿物＾４０Ａｒ－＾３９Ａｒ定年的最佳实验方案,从而获得可信的成矿年龄,本文进行了东川落雪铜矿稀矿山段落雪组角砾状矿石硅质角砾流体包裹体及其固体粉末的＾４０Ａｒ－＾３９Ａｒ对比实验;先采用真空击碎技术提取硅质角砾（ＣＤ－５－２）的流体包裹体进行＾４０Ａｒ－＾３９Ａｒ分析,接着对击碎后的固体粉末样品进行常规的＾４０Ａｒ－＾３９Ａｒ阶段加热分析（１７０～１８０℃）。与以往样品的流体