Strong, localised country-rock contamination and partial homogenisation of a mafic magma: An example from west central Sweden

A dolerite sill cutting slightly older basalt in west-central Sweden shows a strong chemical variation (54% < SiO₂ < 73%) within a restricted area (< 100 × 100 m²). The linear correlation among almost all elements is extremely high; in addition, _NdT is strongly correlated with the SiO₂ content. Least-square hyperbolic-ratio and three-element ratio modelling (common denominator) suggests that most of the chemical variation is explained by mixing and/or micro-mingling. In all, we test 407 hyperbolas, of which 402 are fitted. The five ratio pairs, which could not be fitted to a hyperbola using a least-square fitting procedure, have the ratio Th / Eu in common. Testing the goodness of fit is problematic for hyperbolic distributions; for comparing purposes we sum the distances to chords approximating the hyperbola. Mobile and immobile elements behave similarly, suggesting that no elements are lost or added from outside the system. The data suggests that already the most mafic of the analysed rocks is a mixture of the ‘normal’ dolerite and a siliceous crustal rock. A mafic magma intruded into the base of the crust, where it fractionated resulting in a decreased Mg number. The magma was then contaminated with country rocks in an intermediate magma chamber due to country rock melting; during mixing/mingling almost no fractionation took place. The contaminated rock suggests the presence of a fluid phase. This was probably a prerequisite for country-rock melting. Enrichment in some incompatible elements suggests that besides major mixing/mingling a thermochemical separation process has affected the most felsic rock enriching it in light rare earths and Zr.     

The Aptian-Cenomanian flora of primor’e, part 2: Correlation of floral assemblages

Taxonomic composition of plant fossils from the Aptian-Cenomanian sediments of the Alchan, Razdol’naya, and Partizanskaya depressions of Primor’e is studied in detail. Each of the established floral assemblages characterizes a particular stage of flora stabilization. Correlation of the assemblages is performed. Floral assemblages of the Alchan depression, which occur in association with macrofauna, are suggested to be the standard ones for the southern Far East. New species are described.     

Application of grey correlation method to evaluate potential groundwater recharge sites

Artificial recharge is a practical tool available for increasing the groundwater storage capacity. The efficiency of artificial recharge is related to various hydrogeological factors of the target area. In this study, a variable saturated groundwater flow model, FEMWATER, was used to evaluate the arrival times of recharged water that infiltrates from an artificial recharge pond to the groundwater table under various hydrogeological conditions. Forty-five arrival times were generated by FEMWATER. The relationships between the arrival times and hydrogeological factors used in the simulation of FEMWATER were analyzed by the grey correlation method. The results show the order of importance of the factors as they influence the arrival time. In order from high to low importance, they are α, D _g, θ _e, D _p, K _S and β. D _g and D _p are interpreted as the potential for movement of the recharge water; θ_e is the water storage capacity of soil, and K _S represents the ability of soil to transport water. α and β describe the characteristic curve of the unsaturated soil. The method was applied to evaluate a suitable site for artificial recharge in the Yun-Lin area. Grey correlation analysis was performed to obtain the grey correlation grade using the minimum arrival time as a reference sequence. An index is proposed herein to determine the recharge efficiency of 20 sampling sites. A contour mapping of index values at the 20 sampling sites identified three areas for artificial aquifer recharge in Yun-Lin. Area A in the upper plain is considered more appropriate for groundwater recharge than areas B and C in the coast.     

Real-time measurement of volcanic SO2 emissions: validation of a new UV correlation spectrometer (FLYSPEC)

A miniaturized, lightweight and low-cost UV correlation spectrometer, the FLYSPEC, has been developed as an alternative for the COSPEC, which has long been the mainstay for monitoring volcanic sulfur dioxide fluxes. Field experiments have been conducted with the FLYSPEC at diverse volcanic systems, including Masaya (Nicaragua), Poás (Costa Rica), Stromboli, Etna and Vulcano (Italy), Villarica (Chile) and Kilauea (USA). We present here those validation measurements that were made simultaneously with COSPEC at Kilauea between March 2002 and February 2003. These experiments, with source emission rates that ranged from 95 to 1,560 t d⁻¹, showed statistically identical results from both instruments. SO₂ path-concentrations ranged from 0 to >1,000 ppm-m with average correlation coefficients greater than r ²=0.946. The small size and low cost create the opportunity for FLYSPEC to be used in novel deployment modes that have the potential to revolutionize the manner in which volcanic and industrial monitoring is performed.     

钢筋混凝土框架结构在小震作用下失效相关性的拟动力模型试验研究

通过两榀二层三跨规范钢筋混凝土对称、非对称框架结构模型的拟动力试验,对试件在小震作用截面约束的失效相关性进行了分析,并与文献中的Monte-Carlo随机模拟结果进行了比较,进一步验证了规范钢筋混凝土框架结构在小震作用下失效独立的相关性结论。     

北极海冰和北半球500hPa极涡的相互关系

利用NCEP/NCAR 2.5°×2.5°的500 hPa高度场月平均再分析资料和1°×1°的海冰资料分别计算了北半球500 hPa极涡面积、极涡强度指数和北极海冰面积指数,分析了它们的经向分布、周期变化以及长期变化趋势中的突变。结果表明,海冰和极涡在经向分布上有明显差异,就东西半球而言它们的相对位置也不一样。除了都具有4个月、准半年、准1 a、4~5 a和10 a的共同周期外,还呈现出各自的周期变化。北极海冰面积自20世纪80年代以来呈明显减小趋势,北半球极涡面积也呈减小趋势,但是它们发生突变的时间却完全不同。海冰与极涡面积有显著的正相关关系,但海冰和极涡强度、极涡面积和极涡强度之间的关系却纷繁复杂。     

岩土参数相关性的地基承载力模糊可靠性分析

地基的失效可视为模糊事件。影响地基承载力因素表现出空间变异性。根据随机场理论描述土性参数的空间变异性,考虑土性参数的自相关性及其互相关性,得出参数间的相关性在可靠性分析中不可忽视的结论。     

贵州省金沙煤田龙潭组岩煤层测井对比方法

龙潭组是金沙井田的主要含煤地层，含煤达12~15层，其中7、8、9、11、12五层煤较稳定，为主要可采煤层。根据测井物性曲线与地质岩心的对比分析，总结出该组煤岩层的共有测井物性规律：低密度、中低电阻率、较高中子孔隙度和较低的纵波速度，以及其特有规律如：5、6、7、8、9煤层的低自然伽马，11、12煤层较高的自然伽马等特征。结合煤层测井曲线形态特征及其与顶、底板以及和煤层上、下标志层间组合关系，进行了全煤系地层的对比，揭示了该井田煤层的分岔、合并、冲刷、沉缺、煤层厚度等变化规律。     

云南红土型矿床含矿红土剖面对比研究

凡在风化壳红土形成过程中形成,并保留至今的具有工业价值的各类矿床,均可称其为“红土型矿床”。铁、钛、金、锡、钴等云南红土型矿床,易采治(湿法),其基岩岩性与矿化虽差异甚大,但其最终形成的含矿红土,化学性质却较为接近。