东营凹陷沙三段烃源岩中火成岩岩石学特征分析

东营凹陷沙三段烃源岩中发现一些规模不大的玄武岩和辉长岩体。通过对其岩性及产状、岩石化学和地球化学元素分析，认为研究区玄武岩是碱性－亚碱性橄榄玄武岩；辉长岩的岩石化学和微量元素组成与上述玄武岩相似，认为它们具有同源性，只是辉长岩没有喷发到地表而被封存在刚刚沉积下来的沙三段烃源岩中。水下喷溢的玄赋岩对烃源岩的沉积和生烃演化具有促进作用，辉长岩可以造成局部烃源岩的热变质作用。     

A New Digestion and Chemical Separation Technique for Rapid and Highly Reproducible Determination of Lu/Hf and Hf Isotope Ratios in Geological Materials by MC-ICP-MS

A new digestion procedure and chemical separation technique has been developed for measurement of Lu/Hf and Hf isotope ratios that does not require high‐pressure bombs or use of HF or HClO₄ acids. Samples are digested in dilute HCl or HNO₃ after flux‐fusion at 110 0 °C in the presence of lithium metaborate. High field strength elements (HFSE) and rare earth elements (REE) are separated from this solution by co‐precipitation with iron hydroxide. The dissolved precipitate (in 2 mol l^?1 HCl) is loaded directly onto a standard cation exchange column which separates remaining sample matrix from the heavy REE (Lu+Yb), and the middle‐light REE and HFSE (Hf). The middle‐light REE and individual HFSE are then separated (10.5, 9 and 6 mol l^?1 HCl) using a miniaturized column containing TEVA spec resin which provides a REE‐, Ti‐ and Zr‐free Hf cut. This chemical separation scheme can also be readily adapted for isotopic analysis of the Sm‐Nd system and/or the other HFSE (Ti, Zr). Total procedural blanks for this technique are < 10 0 pg and < 2 pg for Hf and Lu, respectively, even when digesting large (0.5 g) samples. We present data from replicate digestions of international rock reference materials which demonstrate this technique routinely reproduces Lu/Hf ratios to < 0.2% (2s) and ¹⁷⁶ Hf/¹⁷⁷ Hf isotope ratios to < 30 ppm (2s). Moreover, the technique is matrix‐independent and has been successfully applied to analysis of diverse materials including basalts, meteorites, komatiites, kimberlites and carbonatites. The relative simplicity of this technique, coupled with the ease of digestion (and sample‐spike equilibration) of large difficult‐to‐dissolve samples, and the speed (2 days) with which samples can be digested and processed through the chemical separation scheme makes it an attractive new method for preparing samples for Lu‐Hf isotopic investigation.     

Geochemical－Sequence Stratigraphy and Its Application Prospects in Lake Basins

As a useful approach for hydrocarbon exploration,the sequence stratigraphy has been commonly accepted.The concepts of sequence and parasequence provide a state-of -the-artframe-work for studying the distribution and characters of depositional system,and analyzing the occurrence,distribution,characteristics of source,reservoir and seal-play elements.The newly-developed geochemical -sequence stratigraphy focuses mainly on the occurrence,distribution and characters of source rocks and reservoir hydrocarbons within a chronostratigraphic framework,Integrated with sequence wtratigraphy,geochemistry can be used to study the surce rock potential within a sequence wtratigraphic framework and to describe the characteristics of hydrocarbons accumulated in reservoirs,which were predicted by way of sequence stratigraphy.The concept of geochemical-sequence wtratigraphy was proposed by Peters et al.(2000).Constructing a reliable sequence stratigraphic framework is the basis of geochemical-sequence wtratigraphic study although it is not the main goal.High-resolution biomarker analysis is critrical to the construction of a geochemical-sequence stratigraphic model.The geochemical-stratigraphic study involves mainly:(1) the distribution and geochemical characteristics of source rocks with relative sea (lake)-level change;(3) to prodict if these reservoirs bear hydrocarbons and their geochemical features;(4) to be used to construct the time-stratigraphic framework.This paper also summarizes the lake basin types,and introduces their facies associatons,source potential and organic geochemical features.At the end,the authors offer some suggestions about how to carry out geochemical-sequence stratigraphic study in ladcustrine strata.     

岩石中铅和锌的分离与测定

将KHSO4加入在小体积(1mL)试液中,以K2SO4·PbSO4复盐形式沉淀分离Pb,再用NH4Ac溶液热提Pb,1mgPb的平均回收率为100.66%;滤液再蒸至1mL小体积,加入NaCl NaOH小体积两次沉淀分离Fe、Ti、Mn等干扰元素,存在于滤液中的Zn平均回收率为100.5%。分离所得的含Pb2+和Zn2+的溶液用EDTA分别进行滴定,测定范围(质量分数,w)由0.5%下延至0.01%;测定结果与极谱法相一致;精密度(RSD,n=10)试验Pb为2.6%,Zn为1.4%。     

论盐矿化学分析项目的合理选择

盐矿化学分析 ,对研究盐矿组分全貌 ,分析盐类沉积阶段 ,评价盐矿质量 ,制订采卤工艺等方面都是极其重要的手段。依据多年来从事探盐找钾工作的实践经验 ,对盐矿所含易溶、难溶两种盐类组分 ,提出了水溶和酸溶两个系统的分析 ,并针对不同类型盐矿的化学分析项目进行了合理选择     

内蒙古乌审旗板户梁方沸石岩矿特征及开发应用前景

内蒙古乌审旗板户梁方沸石岩矿赋存在下白垩统志丹群洛河组二段二亚段紫红色泥岩和方沸石泥岩中,矿体呈近水平层状产出,为内蒙古地区乃至国内少见的大型矿床。方沸石是沸石族矿物的一种,具有独特的理化特征,可被广泛应用于工业、农业、建筑业、化工业、废水处理等方面。     

大陆板块俯冲和折返的同位素地球动力学

大别 -苏鲁造山带是扬子大陆板块与华北大陆板块之间在三叠纪时期俯冲 -碰撞所形成的超高压变质带。对该带超高压变质岩的稳定同位素研究发现 ,不仅含柯石英榴辉岩出现局部氧同位素负异常 (δ18O =- 10‰ ) ,而且区域上存在氧同位素分布的不均一性 (δ18O =- 10‰～+10‰ )。前者要求榴辉岩原岩在变质前经历过大气降水热液蚀变 ,说明俯冲板块具有大陆地壳特点 ;后者反映扬子板块具有快速俯冲变质的特征 ,否则将达到同位素均一化。榴辉岩氧同位素负异常的保存显示 ,这些超高压变质岩与地幔之间没有发生显著的化学相互作用。因此 ,载有榴辉岩原岩的板块俯冲到 2 0 0多公里深的地幔内部时 ,超高压岩石形成后在地幔中的滞留时间很短(<10Ma) ,致使它们与地幔之间的氧同位素交换没有达到再平衡。榴辉岩中不同矿物对氧同位素测温不仅给出了相互一致的结果 (6 5 0～ 75 0℃ ) ,而且这些温度与阳离子交换温度计的结果 (6 0 0～80 0℃ )相一致。因此 ,在榴辉岩相变质温度下共生矿物之间的氧同位素平衡已被“冻结” ,岩石冷却过程中的氧同位素交换再平衡没有发生 ,从而证明超高压榴辉岩在变质作用后经历了快速降压/冷却过程 ,对应于板块的快速抬升。这些结果首次从地球化学角度证明了大陆板块俯冲—超高压变质—折     

江苏建材非金属矿产资源开发现状与治理对策

江苏建材非金属矿产资源的开发利用在全省矿业经济中占有重要地位，但相应带来了市场竞争剧烈、资源优质劣用、生态环境恶化、安全事故频发等问题，为此，必须加大市场管理力度、综合治理，促进江苏矿业秩序的根本好转。     

Genesis of a mottled horizon by Fe-depletion within a laterite cover in the Amazon BasinGenèse d'un horizon tacheté par déferruginisation dans une couverture à latérite du Bassin amazonien

A mottled horizon in a laterite cover (without any duricrust) was studied by microscopy and quantitative chemical microanalysis. Apart from the voids, light red spots consisting of Fe-rich particles (≈2 μm) are set in clayey plasma. Dark red spots consisted of concentrations of Fe-rich particles. These patterns are inherited. On the border of structural or biological voids, where Fe-depletion features are systematic, gray or yellow spots result from dissolution of the Fe-rich particles and impregnation of the plasma by iron, respectively. The present Fe-depletion is the dominant process that explains the mottled differentiation and the absence of lateritic duricrust. To cite this article: V. Rosolen et al., C. R. Geoscience 334 (2002) 187–195.     

新疆东天山沙泉子地区地球化学特征及找矿预测

新疆东天山沙泉子地区位于雅满苏—沙泉子成矿区的东段 ,地层简单 ,但岩性复杂。受沙泉子深大断裂及沙泉子火山机构共同作用 ,地球化学异常表现为以 Cu- Zn- Ag- Mo为主的内环、以 Pb- Zn(Cu- As- Sb)为主的中环和以 Au或 Au- Ag- As- Sb异常区为主的外环 ,从中心至外围 Cu、Zn等异常强度、规模逐渐减弱 ,Au、As、Sb异常逐渐增强 ,在元素的空间分布上表现出Cu、Zn、Pb、Ag— Pb、Zn、As、Sb(Ag)— Au、As、Sb的元素分带现象。提出沙泉子北、苦水北二处找矿预测远景区 ,有较好的找矿前景