铀对(Ⅱ型)低熟烃源岩生烃演化的影响Ⅱ

在油、气、煤、铀多种能源矿产形成演化富集成藏(矿)过程中,有机-无机相互作用是普遍存在的,在有机质的强大吸附作用及其所提供的还原环境为铀的富集成矿起促进作用的同时,铀也改变了烃源岩的生烃演化进程。本文在Ⅱ型低熟烃源岩中加入碳酸铀酰溶液的条件下进行了生烃模拟实验,对比无铀-加铀样品生烃模拟实验产物的相关参数,以探讨油气生成过程中无机铀所起的作用。从实验结果可以看出,铀可以使产物中不饱和烃向饱和烃转化;促进长链烃的裂解,促进低分子量烃类的产生,从而使CH4的含量提高,使生成的烃类的干气化程度增加。铀可以在低温阶段促进有机质的成熟度,降低烃源岩的生烃门限,使低熟烃源岩早期生成烃类;同时在高温阶段阻止有机质过度成熟,利于所生成烃的保存。因而铀可能是未熟-低熟油气生成可能的无机促进因素之一。     

微生物成矿作用研究的新进展和新动向

本文论述了四种微生物成矿作用的方式及其研究新成果，评述了微生物成矿作用研究方法上的新认识及一些矿种的生物作用研究新进展，阐述了“生物─有机质─流体”成矿系统等一些微生物成矿理论的重点研究方向，最后简述了微生物成矿机制应用于找矿和选矿上的新技术。     

大别山超高压榴辉岩流变强度——来自高温高压实验的证据

利用Griggs型 5GPa高压仪器 ,在柯石英稳定域围压条件下 ( >3GPa)完成大别山超高压榴辉岩流变学实验 ,建立了榴辉岩流变状态本构方程 (流动律 ) : ε=Aexp( -Q/RT)σn ,应力指数 (n)为 3 .4 ,活化能 (Q)为 4 80kJ/mol,结构常数 (A)为 10 3.3.实验结果表明 :( 1)作为两相矿物组成的榴辉岩 ,其流变学强度在很大程度上取决于强相矿物 (石榴石 )和弱相矿物 (绿辉石 )含量比例 ;( 2 )天然榴辉岩塑性变形机制是以位错蠕变为主 ;( 3 )根据实验成果比较榴辉岩和上地幔方辉橄榄岩流变学强度相当 ,两者耦合在大陆深俯冲 10 0km左右深度发生拆沉作用可能性很小 ,与上地幔上隆 (upwelling)作用有关的造山期后伸展作用对超高压岩石折返更具有重要意义 .     

Oxidation Experiment of Natural Megacrystal Ch'nopyroxene: Implications for Assignment of Mossbauer Spectra

The Mossbauer spectra of natural megacrystal clinopyroxene are usually fitted by 4 sets of symmetric doublets, A-A', B-B', C-C' and D-D', respectively, in terms of increasing Qs value in literature. But the assignments of those doublets are quite different, except the D-D' doublet assigned to Fe3+ at the lattice site Ml in previous papers. Particularly, the assignment and interpretation of the C-C' doublet are diverse.The oxidation experiments of natural megacrystal clinopyroxene collected from the Hannuoba basalt, North China, were performed under controlled conditions of temperature at 1000℃ and oxygen fugacity of FMQ buffer in 1, 2, 3 and 5 days respectively. The oxidized samples were then measured by X-ray diffraction spectrometry and Mossbauer spectrometry. The oxidation of clinopyroxene is characterized by Fe2+→ Fe3+ at Ml under the subsolidus conditions, which is consistent with the increase of the area of the D-D' doublet when the heating time increases. Accordingly, the area of the A-A' and B     

Modelling ion composition in seepage water from a column experiment with an open cut coal mine sediment

Secondary reactions occurring in pyrite-containing sediments from open cut coal mines are complex and not fully understood. In this study, the changes in seepage water composition in a column experiment with a sediment containing pyrite (5.6 g kg⁻¹) were evaluated using a chemical equilibrium model. A column experiment with artificial irrigation (730 mm water yr⁻¹) was carried out for 2 yr with a sediment from the open pit mine Garzweiler, Germany, at the Institute of Applied Geology. Tracer (LiCl) was added to the sediment. Seepage water composition at 52 cm depth was sampled weekly. Redox potential and the water potential were also recorded weekly. Sulphate and Fe(II) were the dominant ions in the seepage water with concentration maxima of 500 and 350 mmol l⁻¹ after 50 days (0.7 pore volumes (PV)). Minimum pH values were around 0.8 after 100 days (1.4 PV), but increased subsequently and reached 2.4 after 700 days (9.5 PV). Ion activity product calculations indicated the intermediate formation of gypsum (19th–480th day of the experiment). Solutions were undersaturated with respect to alunite, jarosite, jurbanite, schwertmannite, melanterite, gibbsite and goethite during the whole experiment. The model of coupled equilibria which included inorganic complexation, precipitation/dissolution of gypsum and multiple cation exchange was tested. Pyrite oxidation and pH-dependent silicate weathering were considered using simple input functions. Transport was modelled using a field capacity cascade submodel. Model results showed satisfactory agreement with measured values for pH and concentrations of SO₄, Fe, Mg, Ca and Al. Correlation coefficients lay between 0.7 and 0.9 and linear regression coefficients (modelled against measured) were 1.5 (Ca), 1.0 (Fe, SO₄), 0.8 (Mg), 0.7 (pH) and 0.6 (Al). The results showed that the protons produced during pyrite oxidation (94 mmol_c H⁺ kg⁻¹) were mainly released into seepage water (as HSO₄⁻ and H⁺). Cation exchange reactions buffered 20 mmol_c of H⁺ kg⁻¹ sediment, and Al released by silicate weathering accounted for 3.6 mmol_c H⁺ kg⁻¹. Modelling was useful to further understand the significance of different pH buffer reactions.     

合成碲金矿及其热液蚀变实验研究初探

通过实验合成出了碲金矿 ,并对其进行了 2 0 0℃、80℃温度下不同 p H溶液中的蚀变实验。对碲金矿及蚀变产物分别进行了 X-射线粉晶衍射、矿相显微镜鉴定及电子探针和光电子能谱分析。实验结果表明 ,在中性、偏酸性和碱性溶液的实验条件下碲金矿基本保持稳定 ,而在碱性稀溶液实验条件下可观测到少量含 Fe、 Te、 Au新相的生成及碲金矿表面氧化态碲的明显增加。     

土壤石油微生物降解影响因子的正交实验分析

利用微生物来降解土壤中的石油类污染物，是当前应用前景最好的土壤石油处理方法。多种因素同时制约着石油类污染物的生物降解。为了定量化各因素对彼此的影响，探求促进正向作用、抑制负向作用的途径，为各因素制定适宜的施用时间顺序以及施用量，以最大限度地加快降解速度，笔者设计了本文中的生物降解实验。结果表明，使用多因素复合处理方法可以在土壤石油处理中收到很好的效果；在实验的不同阶段，各影响因素的重要性及最优水平也会不同程度地变化。     

Étude expérimentale des transformations de phase dans un gradient thermique : application au granite de Soultz-sous-Forêts,France

The circulation of an injected fluid in the deep granite of the Soultz-sous-Forêts HDR (‘Hot Dry Rock’) site causes important textural and mineralogical modifications. In order to determine the potential crystallization sequences along the fluid pathway, several experiments under thermal gradient were conducted at 600 bar (between 300 and 200 °C). After 40 days, the observed sequences of the newly formed products along the thermal gradient are always as follows, from high to low temperatures: quartz, feldspars, and finally interstratified clays, this implying a significant mobility of aluminium in the solution. To cite this article: A. Baldeyrou et al., C. R. Geoscience 335 (2003).     

新疆玛河安集海灌区给水度变化规律及试验研究

在对新疆玛纳斯河流域安集海灌区进行地表水地下水转换机理和联合调度研究及利用各类集总式、分布式水文模型进行地下水数值模拟时,给水度都是一个十分重要的输入参数。分析研究区的基本地质情况,选取比较有代表性的地块,利用给水度参数测定装置分别测定常值给水度、变值给水度,揭示该区域给水度随地下水埋深的变化规律。试验得出：在计算地下水降雨入渗补给量和灌溉入渗补给量时要用到给水度这一参数,特别是在地下水埋深不大的地区,对计算成果有比较明显的影响;在地表排水沟设计中,如果考虑了给水度随埋深而变的情况,排水沟的尺寸就会发生变化。     

原油裂解过程中正构烷烃的组成变化特征及其地球化学意义

采用高温模拟技术,对原油样品进行模拟实验,并对其裂解过程中正构烷烃的组成和变化特征进行了地球化学研究。结果表明,原油大量裂解生成气态烃之前,原油中的高分子量正构烷烃已经开始裂解,以C1+5烃类裂解成C6～C14化合物为主。随成熟度的增加,C6～C14化合物进一步转化为C1～C5化合物,并伴随苯系物的产出,最终形成甲烷和裂解沥青。在正构烷烃的裂解过程中,苯及其同系物的丰度呈明显增加趋势,可以作为原油裂解程度的潜在判识标志。此外,利用同样的实验条件对正十六烷进行了对比模拟实验,其产物的组成和变化特征与原油中正构烷烃的基本相同。