青林省含铁地下水的分布与处理措施

本文根据含铁地下水的形成条件将吉林省含铁地下水划分为四个区,并论述了各区的分布特征。综合国内目前各种地下水除铁技术,着重对各除铁系统的方法、基本原理和适用条件以及经济效益等进行了论述。从环境水文地质学的角度,提出了在含铁地下水区寻找低铁地下水的方法,并通过实例验证是可行的。     

Differentiation Mechanism and Evolution of High-level Magma Chamber at Xiangshan,China

The calc-alkaline volcanic magmas,which formed the Mesozoic uraniferous volcanic complex of Xiangshan,resulted from partial melting of the mixture of lower crust and enriched mantle with a high mixing proportion in a specific tectonic setting such as active continental margin or ocean-continent collision zone.The preliminary concentrations of Uand Th occur in low-degree par-tial melts.Only small part of these melts was rapidly extracted and erupted and most intruded into the high-level magma chamber(depth:12-13 km) of the compressed upper lithosphere ,in which occurred a strong differentiation which would resulted in strong preconcentrations of the high-hygromagmaphile elements U and Th associated with strong depletion of the 3-d transition ele-ments Ti,Sc,Co,Zr,etc.At the final stage of subduction of the West-Pacific-Kula plate towards the Asian continental plate,the regional tectonic environment was transformed from a compressive in-to a tensional setting.The strongly differentiated,U(and Th) enriched silicic alkalic magmas in high level magma chamber extensively erupted,extruded and intruded.The hydrothermal fluids released as a result of late volcano-degassing and dewatering during crystallization-solidification of magmas,re-sulted in the remobilization,leaching,migration and reconcentration of uranium ,which had been preconcentrated in volcanic rocks.Therefore,specific regional petrogeochemical criteria are expected for the uraniferous volcanic series.     

Volatile constituents in magmatic inclusions

Laser Raman microprobe has been applied to the analysis of volatile components in shrinkage gas bubbles of individual magmatic inclusions in quartz crystal fragments and phenocrystals from the Mesozoic volcanic complexes of Tonglu and Shouchang, Zhejiang Province. Quantitative analyses are given for CO₂, CH₄, H₂O, CO, H₂, N₂, H₂S, and SO₂. In conjunction with the microthermometry and microbarometry data and the chemical composition of magmatic inclusions, the results permit one to calculate the physico-chemical parametersP _total,fO ₂ ,fCO ₂ ,fCH ₄ ,fH ₂O,fCO, andfH ₂ at the time individual magmatic inclusions were trapped. Based on the data obtained, some physico-chemical conditions for the Mesozoic volcanic magma evolution in the Tonglu and Shouchang areas are discussed. This work shows that this type of studies has become an indispensable new and rising domain in modern magmatic petrology, especially modern volcanic petrology. It can help us to reconstruct the physico-chemistry of the crystallization-evolution of a natural magma. The project was financially supported by the National Science Foundation of China.     

Lower Boundary of the Marine Pleistocene in Northern Shelf of the South China Sea

A marine stratigraphic sequence across the Pliocene / Pleistocene boundary has been found in the north-ern continental shelf of the South China Sea. The marine Quaternary deposits in the Yinggehai Basin may ex-ceed 2,000 m in thickness, probably providing the best section for studying the lower boundary of the marinePleistocene in South China. The vertical succession with planktonic foraminifers and nannofossils revealed inboreholes in the basin has been well correlated with that in the international stratotype section of thePliocene / Pleistocene boundary at Vrica, Italy, resulting in the acquirement of a biostratigraphic boundary at1.64 Ma. This boundary, however, does not coincide with any prominent lithological palaeoenvironmentalchanges in the study area and can hardly be used in geological practice. There are, in contrast, significantchanges at the level of LAD of Globorotalia multicamerata sensu lato located below the above-mentionedboundary. The percentage of planktonic foraminifers in the total population and preservation of foraminiferaltests display great changes at this level corresponding to a clear onlap on the seismic profiles and indicating adepositional hiatus at ca. 2.0-2.5 Ma. Since the level can be widely traced in the Pearl River Mouth Basin andthe Beibu Gulf Basin and well corresponds with the marked depositional environmental changes recorded inthe west Pacific and other regions, it is recommended that the Plio / Pleistocene boundary be drawn at the levelof Gr. multicamerata sensu lato LAD, roughly concurrent with the Gauss / Matuyama turn.     

鄂尔多斯盆地南部延安组水下分流河道型湖泊三角洲体系的沉积构成

采用过程沉积学和成因地层分析相结合的方法,在鄂尔多斯盆地南部延安组中识别出了一种新的湖泊三角洲沉积体系。它与普通河控型湖泊三角洲的主要区别是下三角洲平原部分不是由典型的分流河口坝和前三角洲沉积组成,而是由多分支的水下分流河道、水下决口扇和湖泊沉积组成。在边缘三角洲部分,时常受波浪作用的改造,并形成各种类型的湖滨沉积。本文比较详细地讨论了这类湖泊三角洲的沉积构成及其发育的边界条件。     

井潮系数,气压系数与地震关系的探讨

本文就井潮效应及气压效应的变化特征与地震关系,以及地震预报方法可行度进行了分析研究和初步探讨,结果表明气压系数、井潮系数的变化与地震关系复杂。但在判断确认、预报地震强度、地点方面有可取之处,该预报地震新方法值得进一步深入探讨和研究。文中以滇01井为研究对象,以1984年的回归参数为正常动态。分别求出各项参数的均值z_o与标准误差σ_o以z_o-4σ≦z_o+4σ为正常涨落范围。在此以外的单因子N型脉冲,或多因子单脉冲视为异常。其映震率为77.8%,震前异常预报可行率55.6%。地震漏报率为22.2%,地震虚漏报率为44.4%。     

云南剑川早更新世剑齿象化石

袁氏剑齿象(新种)(Stegodon yuani sp.nov.)是根据发现于云南省大理白族自治州剑川县东山脚村附近的两颗上第三臼齿建立的。 化石产于早更新世湖泊和滨湖河流相的东山组上部粉砂质粘土层中。它稍原始于东方剑齿象(S.orientalis),而在进化水平上又稍晚于先东方剑齿象(S.praeorintalis)。     

Comparison of the rise of water level in the typical catchments,Three Gorges Reservoir area

Water level is an important index for studying hydrologic processes. Water level rise processes were studied in three catchments (catchment I, II, III in Chen Jiagou watershed in the Three Gorge Reservoir Area) with different areas to provide useful information to inform data extension from a gauged-catchment to an ungauged catchment. The results showed that there are seasonal changes in the dominant driving mode of the rise of the water level. The rise of the water level in March is likely mainly driven by the mode of stored-full runoff, and in September or October, it is mainly driven by Horton-flow. The correlation coefficients of all indexes were significant among the three catchments, suggesting that these catchments have similarities and that water level data extension is likely to be completed successfully between the large catchment (III-Catchment) and the small catchment (I-Catchment). It was confirmed that there is good similarity between the 0.6 km2 and 6 km2 catchments, and the data correlation is good between the catchments with the area differences in the Three Gorges Reservoir Area. In addition, the rise processes of the water level in the catchments were not only different under the same rain conditions, but this difference could also change with the rain condition.     

高精度磁测在青海省阿尔茨托山地区划分地质构造中的应用

推断地质构造是磁测资料解释的组成部分,是对基础地质资料进行综合分析的重要参考,内容包括推断构造(断裂构造、火山构造)、地层(磁性火山岩地层、磁性变质岩地层)和侵入岩等。该文以青海省阿尔茨托山地区1∶5万地面高精度磁测成果为例进行分析,对区内的地质构造及岩浆岩分布等形成了一定认识,推断断裂构造17条并划分了区内火山岩地层、侵入岩体的分布范围,进一步完善了区域地质构造格架。