Geochemistry of granitoid rocks and crustal evolution, Zhejiang Province, China— II. Proterozoic granitoid rocks

Proterozoic granitoid rocks in Zhejiang Province were formed in the Shengongian period (1.8–1.9 Ga) and the Late Jinningian period (0.6–0.9 Ga), respectively. Petrogenetic problems are discussed based on chemical (major, trace elements and REEs) and Nd-Sr isotopic compositions. The Shengongian granites resulted from partial melting of the Badu Group and the Late Jinningian granites are of mantle derivation with or without contamination of crustal material. The crust in Zhejiang had undergone three major periods of growth during 2.6–2.7 Ga, 0.8–1.1 Ga and 0.10–0.12 Ga after it was generated in Archean time. Compositional fractionation in the process of crust evolution is not evident. The presence of Late Jinningian granites of mantle and mantle-crust-derivation along the Jiangshan-Shaoxing Fault is indicative of crust subduction at that time. This project was finantially supported by both the National Natural Science Foundation of China (No. 9490011) and the Zhongguancun Test Center.     

流动注射分析及其在地质样品痕量元素测试中的应用

简述了流动注射分析方法的发展及其特点,介绍了流动注射在线分析技术,包括流动注射－原子光谱法、流动注射－分光光度法和流动注射－电化学分析法等联用技术在地质样品分析中的应用情况。     

Sediment heavy metal record in Lake Baikal: natural and antrhopogenic sources

Geochemical analysis of six radiometrically dated short cores of recent sediment from Lake Baikal shows clear evidence of enhanced Pb supply. However, the sediment concentration increases are very small; the average Pb concentration rises from a baseline value of 10.9 g g^-1 to a peak value of only 14.8 g g^-1. In contrast to the more polluted lakes commonly studied in Europe and North America, variation in Pb concentration is far more strongly influenced by natural variation than by pollution. In sediment deposited over the last 150–200 years 73% of the variance in the sediment Pb concentration can be accounted for by variation in bulk composition of the sediment, and by atmospheric pollution. Factors influencing Pb concentrations over this time period are, in order of decreasing average importance (fraction of total variance explained), catchment supply (indicated by ²²⁶Ra activity variation) (43%), anthropogenic Pb emissions (24%), and dilution by ferromanganese hydroxides (6%). On longer (1000s of years) time scales dilution by biogenic silica is probably more important.The recent enhanced supply of catchment Pb correlates with accelerating accumulation rates, indicating a link with enhanced erosion. Anthropogenic sources dominate only in the southern basin, where local fossil-fuel burning industry is situated. The evidence for a local industrial source for the Pb pollution is strengthened by the high correlation between the inventories for Pb and for spheroidal carbonaceous particles. The absence of detectable anthropogenic Pb enrichment in the northern part of the lake suggests that long-distance Pb pollution is small compared with the local natural supply.     

黔南泥盆系的风暴遗迹相

风暴沉积岩在黔南泥盆系地层中比较常见，其中的遗迹化石也较为丰富，为研究风暴遗迹相提供了良好的场所。风暴作用的强度和持续时间影响了沉积环境的水能量、含氧量等物化条件，遗迹化石群也随之有所变化。本文研究了发生在Ｇｌｏｓｓｉｆｕｎｇｉｔｅｓ，Ｓｋｏｌｉｔｈｏｓ，Ｃｒｕｚｉａｎａ和Ｚｏｏｐｈｙｃｏｓ等不同遗迹相环境中的风暴沉积遗迹化石组合，把它们划分为三种类型：（１）单调型风暴遗迹相，风暴作用较弱，风暴沉积过程中的遗迹化石属种和数量较少，但仍与风暴前后的遗迹化石组合属于Ｓｅｉｌａｃｈｅｒ（１９６７）的相同遗迹相；（２）混合型风暴遗迹相，风暴沉积形成新的遗迹相附加于较低能的遗迹相中；（３）多元混合型风暴遗迹相，随着强烈风暴作用强度的变化，在风暴沉积期出现两种以上遗迹相的沉积环境     

Cd, Cr, Cu, Ni and Pb in the water column and sediments of the Ob-Irtysh Rivers, Russia

Concentrations of Cd, Cr, Cu, Ni and Pb were determined in filtered water, suspended particulate matter, and bottom sediments from a 2000 km section of the Ob and Irtysh Rivers. Dissolved Cd, Cr, Cu and Ni concentrations are similar to, or higher than, results from other Russian Arctic and large world river-estuaries. Concentrations of Cd, Cr, Cu, Ni and Pb in suspended particulate matter are generally comparable to results from other Russian Arctic and large world rivers and estuaries. Comparison of trace metal ratios in crustal material and suspended particulate matter and bottom sediment suggests that the source of Cr, Cu and Ni is continental weathering. Particulate Cd and Pb are elevated relative to their crustal abundance, suggesting a source of these metals to the Ob-Irtysh in addition to continental weathering.     

花岗岩类某些矿物中微量元素和挥发分离子探针[SIMS]研究

本文采用离子探针(SIMS)分析花岗岩类磷灰石、锆石和黑云母等矿物中微量元素和挥发分,来探讨花岗岩类成矿作用。结果证明,不同时代和不同成因的磷灰石和锆石具有某些指纹特征;并显示了花岗岩类所含微量元素和挥发分之间存在某种相关关系。     

遗迹相及其古环境的意义

遗迹相是指一组具有特征的遗迹化石组合,在一段相当长的地质时期中不断的重视以及它们的环境意义。本文结合中国实例指出7个常见和通用的遗迹相及其沉积环境。浊积岩或复理石沉积中含有Nereites遗迹相,文内列举了目前已知的中国10个复理石产地,证明它们主要分布在两个板块构造单元的对接（消减）带。     

新疆震旦纪痕迹化石Planolites,Chondrites的发现及其意义

新疆震旦纪痕迹化石的存在及其形态特征,反映那里最早的水平潜穴,在震旦纪冰期前即已存在,但痕迹细小,且相互交切,绝不分叉。之后始出现分叉现象,并向枝形潜穴方向演变。     

Petrology of a new basalt occurrence in Hungary

Summary A new occurrence of basalt (minimum K/Ar age 57.9 ± 2.2 m.y.) is reported from Budaliget, near Budapest. Major and minor element concentrations show that the basalts are alkaline and potassic in nature ranging from olivine tholeiite to moderately undersaturated basanite. High mg-values and concentrations of Ni and Cr indicate that some of the samples may represent primary compositions. High pressure accidental xenoliths, xenocrysts and cognate megacrysts are frequent and the chemical zoning patterns of olivine and pyroxene phenocrysts indicate a complex evolution and polibaric conditions for the crystallization. The discovery of the new basalt occurrence is important from a geodynamical point of view: prior to the last two major geodynamical events (Plio-Pleistocene rifting with associated alkali basaltic volcanism and collision of microplates with associated Miocene calk-alkaline volcanism) the continental lithosphere below NE Transdanubia may have experienced another rifting period in the Paleocene or Upper Cretaceous.With 7 Figures     

豫西太原组(C_3)中一种罕见的遗迹化石——沙蠋粪化石

沙蠋粪化石保存在豫西荥巩煤田西部晚石炭世太原组(C_3)上部泥晶灰岩中。化石完整、形态逼真、十分罕见。该灰岩动植物化石((竹蜓)、腕足类、有孔虫等碎片)丰富,推测其古环境可能是潮坪上低洼积水的潮池(与现代生活在潮坪环境中的沙蠋一致),因此地层中的沙蠋粪化石的出现,可作为鉴定潮坪环境的重要标志之一。