743阳离子交换快速分离——ICPS-PGS2单道扫描直读光谱仪测定地质样品中15个微量稀土元素

本文采用过氧化钠(Na_2O_2)熔样,743阳离子交换树脂快速分离,0.4mol/L柠檬酸25ml洗脱稀土,无需浓缩,即可用lCPS-PGS2单道扫描直读光谱仪直接测定15个微量稀土元素。在选择的最佳测量条件下,本法测定下限为0.005~g/ml(Eu)-0.50μg/ml(Ce),标准加入回收在88％—110％之间,样品分析精度为3.3％—17％,样品分析结果与参考值相符。本法适用于一般地质样品中微量稀土元素的例行分析。     

龙门山平驿铺组沉积体系及旋回层序研究

本文首次从龙门山区下泥盆统平驿铺组中，划分出河口湾、三角洲、滨岸和陆棚四个沉积体系和三个Ⅲ级Ｔ－Ｒ旋回层序。平面上，四个沉积体系组成了扬子板块西侧的古大陆边缘由过渡相区和滨岸相区相间分布的古地理格局；垂向上，两相区中的三个Ⅲ级Ｔ—Ｒ旋回层序也由不同的沉积体系组成，旋回层序的演化虽然受构造差异沉降影响，但仍以Ⅲ级海平面升降变化为主要控制因素，并具同步演化规律，可分别代表古大陆边缘活动型和相对稳定型的两种Ⅲ级Ｔ—Ｒ旋回层序模式。     

北祁连加里东造山带从挤压到伸展造山机制的转换

早古生代早期，北祁连造山带发生强烈的挤压变形作用，形成加里东期的俯冲－增生杂岩、高压变质岩，并使造山带岩石圈地壳加厚缩短。志留纪末期，加厚的造山带岩石圈由于垮塌作用及根部的拆沉作用，使造山带从挤压造山机制转换为伸展造山机制，并进入后造山伸展作用阶段，增厚的岩石圈开始减薄，发生不同层次的伸展作用，同时伴随花岗岩及Ａｎ∈变质岩的穹隆以及泥盆纪磨拉石盆地上叠盆地（Ｃ－Ｔ）的形成。石炭纪末，北祁连造山带岩石圈地壳已基本减薄到正常厚度。而现今的北祁连造山带的缩短和抬升则为喜马拉雅期再造山作用的产物     

浙江缙云斜发沸石水的核磁共振分析

本文应用宽线NMR技术,结合红外测定,研究了缙云斜发沸石中水的结构类型、存在状态、运动特征和热稳定性。结果表明:缙云斜发沸石中的沸石水按其运动特性可以分为受阻旋转水、自由旋转水和自扩散运动水三种类型,它们以谱线中分裂的双线和线宽不同的单峰相区别。低温时,受阻旋转运动的水在晶格中转变为刚性配置。其脱水次序决定于各类型水与沸石结构骨架键合的强弱,脱水是连续的。研究显示缙云斜发沸石的结构骨架相当疏宽,骨架对水分子的吸引力没有严格的方向性,这一特性有利于阳离子的交换。     

长江流域洪水分期规律对水库优化蓄水运用方式的科学支撑作用

针对长江流域大型水利工程汛末防洪和蓄水间的矛盾,根据流域汛期洪水资料和环流形势等天气资料,分析了流域洪水与西太平洋副热带高压位置间的关系,在此基础上采用数理统计等方法分析了汛期洪水的分期特性,并重点分析了三峡和瀑布沟水库汛期洪水的分期特点。分析表明,三峡和瀑布沟汛期洪水存在较为明显主汛与后汛之分,分期时间在8月20日左右。分析结果为三峡和瀑布沟水库分析分期设计洪水、优化汛末蓄水调度方式等提供了良好的科学支撑。     

ICP-AES法测定金属硅中硼磷铝锰钙镁铁等28种微量和痕量元素

采用ICP-AES法对金属硅中的B、P、Al、Mn、Ca、Mg、Fe等28种微量和痕量元素进行分析。根据元素的化学性质制定预处理方法,优化ICP-AES光谱仪测试样品的最佳工作条件。在缺少金属硅标准物质的情况下,选择硅含量较高的国家一级岩石标准物质（GBW07106）进行试验,该标准物质的回收率在95.0%～104.4%之间,相对标准偏差RSD在0.21%～4.01%之间。实际分析工作表明,该方法准确、快速,符合DZ/T 0130—2006的要求。     

金伯利岩中铬铁矿原生表面特征成因类型及其成分特征

对金伯利岩中铬铁矿原生表面特征的成因做出了合理解释,并提出了４种成因类型;通过探讨铬铁矿原生表面特征,化学成分,含矿性之间的关系,初步建立了铬铁矿原生表面特征与金刚石含矿性之间的关系。     

个旧矿区遥感异常信息解译及找矿远景分析

文章以TM多光谱遥感数据为基本信息源,从实际地质情况出发,采用计算机识别和人工判读相结合,对区内的线形、环形构造进行了解译.应用比值 主成分分析的方法对区内热液弱蚀变信息进行了提取.在此基础上,综合利用已知矿床的分布以及遥感构造信息、遥感蚀变晕信息,结合已有的物化探资料,分析出4个找矿远景区.     

Late Mesozoic compressional to extensional tectonics in the Yiwulüshan massif,NE China and their bearing on the Yinshan–Yanshan orogenic belt: Part II: Anisotropy of magnetic susceptibility and gravity modeling

Granitoids play an important role in deciphering both crustal growth and tectonic evolution of Earth. In the eastern end of the Yinshan–Yanshan belt of North China Craton, the Yiwulüshan massif is a typical region that presents the tectonic evolution features of this belt. Our field work on the host rocks has demonstrated two phases of opposite tectonics: compressional and extensional, however, the deformation is almost invisible in the intrusive rocks. To improve the understanding of the tectonic evolution of the Yiwulüshan massif and the Late Mesozoic tectonics of East Asia, a multidisciplinary study has been carried out. In this study, anisotropy of magnetic susceptibility (AMS) and gravity modeling have been applied on these Jurassic plutons (Lüshan, Jishilazi and Guanyindong), which intrude into the Yiwulüshan massif. According to laboratory measurements and microscopic observations on thin sections, the AMS of the Yiwulüshan massif is characterized by secondary fabrics, indicating that the intensive post solidus deformation has reset the (primary) magmatic magnetic fabrics. A relatively gentle NW dipping magnetic foliation has been identified with two distinct groups of magnetic lineations of N34°E and N335°E orientations, namely L_M1 and L_M2, relatively. Gravity modeling reveals a southward thinning of the massif with a possible feeding zone rooted in the northern part of the massif. Integrating all results from structural observation, geochronological investigation, AMS measurement and gravity modeling, two tectonic phases have been identified in the Yiwulüshan massif, posterior to the Jurassic (180–160 Ma) magmatism in the Yinshan–Yanshan area. The early one concerns a Late Jurassic–Early Cretaceous (~ 141 Ma) compressional event with a top-to-the-south to southwest sense of shear. The second one shows an Early Cretaceous (~ 126 Ma) NW–SE ductile extensional shearing. At that time, sedimentary basins widened and Jurassic plutons started to be deformed under post solidus conditions. In fact, the NW–SE trend of the maximum stretching direction is a general feature of East Asian continent during Late Mesozoic.     

Tectonic geomorphology in the Hexi Corridor, north-west China

The Hexi Corridor is a Cenozoic foreland basin system at the north-eastern margin of the Qinghai–Tibet Plateau. Active faults, having clear geomorphological expression, are mainly NW-trending reverse-sinistral faults and NNW-trending reverse-dextral faults. From the south-west to the north-east, landforms can be divided into three parallel zones arranged along the WNW faults. Longitudinally, three transverse uplifted blocks divide the Hexi Corridor into four subbasins. North-eastward motion of the Qinghai–Tibet Plateau and eastward motion of the north-east part of the Plateau resulted in compressive and shear deformations and controlled the geomorphological pattern in the Hexi Corridor.