气液包裹体稳定同位素样品制备及与气液相成分联测方法

本方法研制了一套“气液包裹体稳定同位素样品制备与气液相成分分析联测装置”，将包裹体稳定同位素样品制备装置与气相色谱仪连结起来，能在一个样品中测定出包裹体中的碳、氢、氧稳定同位素及气相和液相成分。整套装置性能良好，主要测定项目均能达到规定的技术指标，并满足包裹体测定要求：①δＤ制样及测定结果的标准偏差≤３‰；②δ＾１８Ｏ制样及测定结果的标准偏差≤０．３‰；③δ＾１３Ｃ制样及测定结果的标准偏差≤０．１     

Determination of Platinum‐Group Elements in Geological Samples by Isotope Dilution‐Inductively Coupled Plasma‐Mass Spectrometry Combined with Sulfide Fire Assay Preconcentration

A method was developed for the determination of platinum‐group elements (PGE) in geological samples by isotope dilution‐inductively coupled plasma‐mass spectrometry combined with sulfide fire assay preconcentration. Samples were fused and PGE analytes were concentrated in sulfide buttons. The buttons were dissolved using HCl leaving PGE analytes in insoluble residues, which were digested in HNO₃ and simultaneously processed for the distillation of Os. The remaining solutions were further prepared for the purification of Ru, Rh, Pd, Ir and Pt using a tandem assembly of cation and Ln resin columns. The eluents were directly analysed by membrane desolvation‐ICP‐MS. Ruthenium, Pd, Os, Ir and Pt were determined by isotope dilution, whereas Rh was determined by conventional reference material calibration combined with ¹⁹³Ir as the internal standard element. The method was validated using a series of PGE reference materials, and the measurement data were consistent with the recommended and the literature values. The measurement precision was better than 10% RSD. The procedural blanks were 0.121 ng for Ru, 0.204 for Rh, 0.960 ng for Pd, 0.111 ng for Os, 0.045 ng for Ir and 0.661 ng for Pt, and the limits of detection (3s) were 0.011 ng g^?1 for Ru, 0.008 ng g^?1 for Rh, 0.045 ng g^?1 for Pd, 0.009 ng g^?1 for Os, 0.006 ng g^?1 for Ir and 0.016 ng g^?1 for Pt when a test portion mass of 10 g was used. This indicates that the proposed method can be used for the determination of trace amounts of PGE in geological samples.     

电感耦合等离子体质谱法测定化探样品中微量砷

通过电感耦合等离子体质谱法测定化探样品中As的分析方法,利用1:1王水在沸水浴中溶矿,用ICP-MS直接测定。方法的检出限为0.0113μg/g,精密度RSD%小于3%,用国家标准物质验证的结果与标准值一致。方法简便快速,适合应用于大批量化探样品中As的测定。     

Uncovering pathways of metal contamination with microscopic techniques and lead isotopic tracing

Over several decades, there has been considerable disagreement about heavy-metal contamination in mining communities as to whether the contamination arose from natural processes such as oxidation and weathering over millennia or from mining activities. More sophisticated geochemical methods and isotopic tracing especially for lead (Pb) may or may not provide definitive answers. We suggest that relatively simple approaches using the microscopic techniques of optical microscopy complemented by scanning electron microscopy and energy-dispersive analyses along with X-ray diffraction can provide definitive answers to the conundrum. Heavy liquid and –53 + 48 µm fractions of soil, pavement and gutter sweepings, dust depositional gauges, long-term dust accumulation, vacuum cleaner dust and ceiling dust were investigated using the above methods. The most common Pb-bearing particles consisted of Pb, Fe, Mn, Al, Si and O. The majority of grains were rounded with cavities and overgrowths, and showed evidence of transport and recrystallisation, probably deriving from post-mining activities and/or earlier geological processes. A small number of samples from ceiling dust, pavement sweepings, vacuum cleaner dust and long-term dust accumulation contained galena with a high degree of crystallinity suggesting a derivation from recent mining and ore concentration activities. High-precision Pb isotopic analyses showed that some samples with extensive oxidation and weathering had absorbed Pb from sources other than mine Pb, and these could be from gasoline, paint or weathering of the country rocks.     

X射线荧光光谱法测定高氟地质样品中氟、钙等元素

采用X射线荧光光谱法测定高氟地质样品中氟、钙等元素,对样品进行熔融制样前处理,理论α系数和经验系数法校正基体效应。应用此方法分析国家一级标准物质和代表性样品,所测元素的精密度(RSD)均小于5%(除含量较低元素);分析不参加回归的标准物质和人工配制的标准样品,测量结果与标准值基本一致。通过实验数据可知,该方法可以满足高氟硅酸盐样品、萤石、萤石型铀矿、磷矿石等样品的测定要求。     

Nonlinear processes in earthquake foci

The results of laboratory experiments on biaxially compressed physical models of a seismic source are presented, discussed and interpreted in terms of nonlinear dynamics; the relation is shown between the degree of seismic pulse coherency (expressed through the amplitude frequency spectra development) and energy (or magnitude) in a series of model experiments. It has been ascertained that the degree of radiated waves coherency plays a more important role concerning the seismic energy release than the size (radius) of the seismic source.The relations among individual source parameters obtained in the laboratory were tested by the analysis of three series of seismograms of aftershocks which followed the 1988 Spitak earthquake (two series) and the 1975 Oroville earthquake (one series). The fundamental effect observed in the laboratory, i.e., the growth of pulse coherency with increasing stress concentration in the focal region (reflected in growing earthquake magnitude), was clearly manifested in all three earthquake aftershock series.Due to derivation by a comparison of the above results, obtained on the basis of nonlinear dynamics with the classical source models by Brune, Madariaga and others, it seems to be namely the self-organizing of the structure itself caused by the increasing stress field in the seismic source, which can answer the question concerning the degree of energy cumulation in the earthquake focus at a given moment.     

不同类型水样中同位素样品采集方法浅析

本文对不同类型水样中同住素样品野外采集方法进行了探讨。根据各种水样的同位素分布情况，进一步探索地下水的来源、补给和运移机理，为实现水资源的计划开发、统一管理服务。     

Permeability of the rocks from the Kola superdeep borehole at high temperature and pressure: implication to fluid dynamics in the continental crust

Permeability of the samples collected from the surface and from the depths of 8–11 km in the Kola SG-3 and from the depth of 3.8 in the KTB boreholes was studied at temperatures up to 600 °C and pressures up to 150 MPa. These PT correspond to in situ conditions of the deep parts of the superdeep boreholes and to the conditions of progressive and regressive metamorphism of the Kola series rocks. The experiments were carried out with fluid filtration parallel and normal to rock foliation and parallel to core axis. The temperature–permeability trend behavior depends on effective pressure and depth of sample collection. At low effective pressure, a temperature increase leads first to a permeability decrease and then to its increase. At higher effective pressure, inversions appear on all the temperature trends of the samples collected from great depths. In contrast, permeability of the samples selected at shallow depth (3.8 km) and on the surface decreases within the entire temperature range. As a rule, with flow parallel to foliation, the values of permeability are higher than with flow normal to foliation. The results of microstructure studies allow to conclude that microcrack initiation and closure, due to a competitive influence of temperature and pressure cause such permeability behavior. In the samples, there are two families of microcracks: with low aspect ratio and those with high aspect ratio. Their effect on rock permeability changes with temperature. On sample heating, the low aspect ratio microcracks close and, on the contrary, high aspect ratio ones open. The total effect is expressed by minima in the temperature–permeability trends. Permeability anisotropy increases with temperature, reaches a maximum at 200 °C and then decreases. Sample permeability decreases with different gradients at simultaneous increase of temperature and pressure, simulating in situ depth increase. Hence, the deep seat rocks can vary greatly in permeability and against the common background of permeability decrease with depth, local deep aquifers may occur. At PT of progressive metamorphism the permeability values were high enough to permit the fluid flow to penetrate the whole volume of rock massif. At PT of regressive metamorphism, the permeability values were a few decimal orders lower, so fluid flow could be concentrated in large disjunctive zones only.     

Latitudinal changes in siphonophore assemblages across the Atlantic sector of the Southern Ocean

Siphonophores are commonly considered to be useful indicators of water masses and water-mass movement, but their employment as such across the wider Southern Ocean has not so far been attempted. We redress this here using archived samples, collected during January–February 1993 along a transect from Cape Town to the South African National Antarctic Expedition (SANAE) base in Antarctica, and compare the patterns generated with those determined from a prior analysis of whole assemblages at lower taxonomic resolution. Twenty-one species were identified from 18 of the original 53 samples collected, and two distinct assemblages were confirmed as separated by the Sub-Antarctic Front. That to the south was characterised by low diversity and high abundance and was dominated by cold-water specialists, whereas that to the north comprised a larger number of subtropical and temperate species at low abundance. Assemblage structure was strongly influenced by the mixed layer depth, sea surface salinity and chlorophyll a concentration, as well as mesozooplankton biomass. Congruence with the whole-assemblage study was high, indicating that this taxon can be suitably employed as a proxy in studies such as this. The study emphasises the value of archived plankton samples and makes a plea for better curation.