华北地台中寒武世米级旋四层序与复合海平面变化

笔者在对华北地区中寒武统颐滩碳酸盐建造露头层序地层学研究工作中首次识别出层序中最基本的地层单元──米级旋回层序，它是露头层序分析最基本的工作单元。本文总结概括出不同体系域内米级旋回层序类型和特征。这些米级旋四层序在塞向上叠加构成高级（五级、四级、三级）旋回层序时表现出周期性和规律性。这种不同级次的旋回层序的形成受不同动力成因引起的具不同周期和频率复合海平面变化的控制。米级旋回层序的识别与复合海平面变化的研究得出中寒武世鲕滩层序的形成经历了若干次周期性的淹没－间断－均衡堆积－加积进积事件，这为盆地充填史的恢复提供了新途径。     

西菲律宾海沉积物稀土元素地球化学

对取自西菲律宾海区3个沉积物柱样（WP1、WP2和WP40）的32个样品的稀土元素（REE）地球化学行为进行了系统的研究。区内沉积物表现出以下特征：①稀土元素含量及总量（ZREE）较低，WP1、WP2和WP40孔的ΣREE依次为72．91×10－6，54．15×10－6和54．18×10－6，REE在粘土粒级中得到了较大富集；②REE球粒陨石标准化的分布模式曲线表现为负斜率，富集轻稀土，WP1、WP2和WP40孔LREE／HREE比值平均值为37．36，26．33和17．16，页岩标准化曲线大致呈水平；③与球粒陨石和页岩相比，Ce都表现为强烈的亏损；以球粒陨石为标准，WP40孔表现为弱的Eu正异常，其他两孔表现为弱的Eu负异常；以页岩为标准，皆显示Eu正异常；④ΣREE纵向变化曲线与CaCO3旋回曲线有良好的对应关系。上述特征表明：①沉积物的来源复杂，有陆源、火山源、生物源和自生源，在所研究的三个孔中，WP1孔含有较多的陆源物质，WP2和WP40含有较多的火山物质；②被粘土吸附是本区REE重要的存在形式；③沉积物形成环境为氧化条件；④据ΣREE的纵向变化曲线与CaCO3旋回曲线，将本区沉积物自下而上划分为末次冰期亚间冰期沉积、冰期最盛期沉积和全新世沉积。     

含油气盆地地球动力学模式

文章讨论了含油气盆地地球动力学模式,其中着重讨论了以下几个问题:(1)沉积盆地地球动力学研究的进展,使得能够提出一种根据盆地所处的板块位置和地球动力学模型进行划分的含油气盆地分类;(2)尽管我们有一些古生代克拉通盆地的地球动力学模式,但其成因机制仍缺乏令人信服的解释;(3)通过大陆内裂谷火山岩化学成分、地温场、构造变形、岩石圈结构以及区域板块构造背景综合分析,我们建立了六种大陆裂谷形成的地球动力学模式;(4)前陆盆地的形成与其周缘造山带密切相关,其地球动力学模式是大陆岩石圈对褶皱冲断带构造负载的挠曲响应;     

陕西洛川黄土沉积物中稀土元素及其它微量元素的化学淋滤研究

本文采用化学淋滤的方法对洛川黄土沉积物的酸溶和酸不溶相中稀土元素以及其它微量元素的分布分配特征进行了系统的分析。     

Characteristics of Volcanic Rocks in the Shoshonite Province, Eastern China, and Their Metallogenesis

The shoshonite province in eastern China is characterized by extensive distribution (ca. 80000 km2) of Late Jurassic-Early Cretaceous (165-100 Ma) shoshonite series with subordinate high-K calc-alkali series. It was formed in a dominantly tensile stress field. In comparison with their analogues in island arcs and active continental margins in other countries, the volcanic rocks in the shoshonite province have their specific characteristics in petrology, mineralogy and geochemistry as well as related mineralization association, which are the comprehensive reflection of the special composition and structure of the mantle and crust of the province and the special Mesozoic regional tectonic setting.     

Behaviours of REE and Other Trace Elements During Pedological Weathering-Evidence from Chemical Leaching of Loess and Palaeosol from the Luochuan Section in Central China

The chemical leaching method is used for a systematic analysis of distribution characteristics of acid-soluble and acid-insoluble REE and other trace elements from the Luochuan loess deposits. The study shows that the acid-insoluble phase in loess and palaeosol is a stable component of old aeolian dusts and is characteristic of the provenance; the acid-soluble phase is the unstable component in the weathering pedogenic process and reflects rock-forming features after accumulation of aeolian dusts. The acid-insoluble REE and acid-soluble Sr and Pb can be used as geochemical indicators respectively to trace the provenance characteristics and the weathering pedogenic process.     

Oxygen Isotope Exchange Kinetics Between Coexisting Minerals and Water in the Aral Granite Pluton of the Altay Mountains, Northern Xinjiang

Coexisting quartz, feldspar and biotite vary widely in their δ18O values and display a remarkable 18O/16O disequilibrium relation; especially, a quartz-feldspar reversal (△ 18OQUartz_feldspar< 0) exsists in the Aral granite pluton of the Altay Mountains, northern Xinjiang. The 18O / 16O exchange reaction definitely occurred between granite and water. Initial δ18O values of the granite and exotic fluid are evaluated by the mass balance consideration. The conventional method of discrimination between various magma derivations simply with δ18O values of either whole rock or separate minerals is misleading and unreliable. Experiments carried out by the authors show that the 18O / 16O exchange reaction is not accompanied by what geologists describe as petrological and mineralogical alteration effect. This decoupling relation implies that exchange reaction occurs at a relatively high temperature during subsolidus-postmagmatic cooling of magmas. The exchange mechanism is mainly diffusion-controlled. It is     

Estimation of in situ viscoelastic parameters of weak floor strata by plate-loading tests

Summary This paper explores an approach to estimation of the viscoelastic parameters of weak floor strata using plate-loading tests. Mathematical equations are derived to describe deformation-time history for the standard Burgers model under three-dimensional stress-strain conditions, which are verified with a finite element model. A number of time-dependent in-mine plate-loading tests were conducted and the values of the viscoelastic parameters were estimated based on the derived equation. It is shown that large discrepancies between the parameter values estimated from the plate-loading tests and those acquired from the in-mine convergence data are the results of neglecting adjacent pillar interaction. Finite element modelling was conducted to investigate the effects of adjacent pillar interactions upon the pillar settlement. Based on the finite element analyses, a correction curve was developed to adjust the viscoelastic parameter values to take into account the interaction between adjacent pillars. With the correction, the parameter values estimated from the plate-loading tests compared favourably with those acquired from the in-mine convergence results.     

南天山蛇绿混杂岩和中天山南缘糜棱岩的40Ar/39Ar年龄及其大地构造意义

⁴⁰Ar/³⁹Ar同位素年龄测定,获得南天山蛇绿混杂岩基质黑云母石英片岩单矿物黑云母的两个坪年龄分别为(370.0±4.8)Ma和(259.0±3.3)Ma;中天山南缘长英质糜棱岩单矿物黑云母的坪年龄为(250.5±7.9)Ma,二云母花岗岩单矿物白云母的坪年龄为(348.9±0.3)Ma。结合南天山古生代沉积特征和塔里木及伊犁-哈萨克斯坦板块古地磁数据的综合分析,提出南天山晚泥盆世至石炭纪早期完成向伊犁-哈萨克斯坦板块的B型俯冲,中-晚二叠世进行陆内A型俯冲造山的板块碰撞演化模式。     

极谱催化波测定天然水中微量锗的研究

系统研究了Ｇｅ－ＡＲＳ－Ｈ２Ｃ２Ｏ４－Ｖ体系报道极谱催化波的影响因素，测定了Ｇｅ－ＡＲＳ－Ｈ２Ｃ２Ｏ４三元配合物的配合比为１：２：１。实验初步证明了该体系催化波为具有吸附性质的平行催化波。本法检出限为０．１４ｍｇ．ｍＬ＾－１，相对标准偏差小于９．８９％，标准回收率为９３．７０％－１０９．０％，０－５０ｍｇ．ｍＬ＾－１的锗具有良好的线性关系。