四川盆地开江地区WT1井震旦系陡山沱组物源分析及构造背景判断*

为厘清四川盆地开江地区WT1井震旦系陡山沱组地层发育的构造背景,重塑其原型沉积盆地,为重建古地理及油气进一步勘探部署工作提供科学依据,利用岩石学、岩石地球化学及碎屑锆石U-Pb年代学手段对该井陡山沱组物源进行了分析。岩石地化结果表明WT1井陡山沱组沉积物源岩为中基性火山岩类且经历了中等程度化学风化作用;碎屑锆石U-Pb年龄主要记录了915~850Ma、794~714.5Ma以及622~700Ma 3个阶段的构造岩浆活动,与扬子克拉通北缘及邻区Rodinia超大陆的裂解演化过程有关,该构造活动背景下的中基性火山岩是WT1井陡山沱组沉积的主要物质来源。结果表明四川盆地开江地区的陡山沱组发育于拉张伸展构造背景,属克拉通内裂陷盆地沉积,有利于烃源岩层的发育;同时为Rodinia超大陆的裂解演化过程提供了重要的年代学演化证据。该成果对深入认识四川盆地的地质结构、沉积-构造演化以及油气勘探的战略部署等具有极为重要的科学意义。     

Soil water dye tracing,with special reference to the use of rhodamine WT,lissamine FF and amino G acid

Three fluorescent dyes (Rhodamine WT, Lissamine FF and Amino G Acid) are compared for use in soil water tracing. Severe limitations are evident, but practical applications are possible. Background fluorescence, adsorption, desorption, pH and other non-adsorptive effects are reviewed in the contexts of soil column work and field tracing of soil water. Lissamine FF and Amino G Acid are to be preferred for soil column work because of their lower adsorption; Rhodamine WT exhibits higher adsorption but is useful in field situations where organic fluorescence backgrounds are high. Semi-quantitative work may be undertaken in soil columns once a priming and flushing procedure has been adopted.     

我国卤水溴资源及其开发前景展望

溴在自然界无独立的矿物 ,呈强分散性稀有元素 ,散布在地壳水圈里 ,以油气田地下卤水、盐湖卤水、矿场盐卤水含溴浓度相对较高。溴在国民经济的用途广泛 ,是我国紧缺物资 ,产不敷消。而我国卤水溴资源分布广泛 ,类型齐全 ,同时常伴有K、B、I、Li等多种有用组分。充分发挥各类卤水溴资源特点 ,提高卤水溴资源综合利用水平 ,其开发前景广阔     

东南极格罗夫山地区夏季的天气特征

利用中国南极科学考察队 1 998年 1 2月至 1 999年 1月在东南极格罗夫山地区地质考察期间所获得的天气资料 ,对该地区的温度、雪面温度、风速、风向等天气要素进行了分析。结果表明 :夏季格罗夫地区温度日变化和盛行风向与中山站相类似 ,但温度日较差和强风频率比中山站大。当受来自北方暖湿气流影响时 ,常出现降雪天气 ;在东风气流控制下 ,天气以晴为主     

Parsimonious wave‐equation travel‐time inversion for refraction waves

We present a parsimonious wave‐equation travel‐time inversion technique for refraction waves. A dense virtual refraction dataset can be generated from just two reciprocal shot gathers for the sources at the endpoints of the survey line, with N geophones evenly deployed along the line. These two reciprocal shots contain approximately 2N refraction travel times, which can be spawned into refraction travel times by an interferometric transformation. Then, these virtual refraction travel times are used with a source wavelet to create N virtual refraction shot gathers, which are the input data for wave‐equation travel‐time inversion. Numerical results show that the parsimonious wave‐equation travel‐time tomogram has about the same accuracy as the tomogram computed by standard wave‐equation travel‐time inversion. The most significant benefit is that a reciprocal survey is far less time consuming than the standard refraction survey where a source is excited at each geophone location.     

Estimating longitudinal dispersion in rivers using Acoustic Doppler Current Profilers

The longitudinal dispersion coefficient (D) is an important parameter needed to describe the transport of solutes in rivers and streams. The dispersion coefficient is generally estimated from tracer studies but the method can be expensive and time consuming, especially for large rivers. A number of empirical relations are available to estimate the dispersion coefficient; however, these relations are known to produce estimates within an order of magnitude of the tracer value. The focus of this paper is on using the shear-flow dispersion theory to directly estimate the dispersion coefficient from velocity measurements obtained using an Acoustic Doppler Current Profiler (ADCP). Using tracer and hydrodynamic data collected within the same river reaches, we examined conditions under which the ADCP and tracer methods produced similar results. Since dead zones / transient storage (TS) are known to influence the dispersion coefficient, we assessed the relative importance of dead zones in different stream reaches using two tracer-based approaches: (1) TS modeling which explicitly accounts for dead zones and (2) the advection–dispersion equation (ADE) which does not have separate terms for dead zones. Dispersion coefficients based on the ADE tend to be relatively high as they describe some of the effects of dead zones as well. Results based on the ADCP method were found to be in good agreement with the ADE estimates indicating that storage zones play an important role in the estimated dispersion coefficients, especially at high flows. For the river sites examined in this paper, the tracer estimates of dispersion were close to the median values of the ADCP estimates obtained from multiple datasets within a reach. The ADCP method appears to be an excellent alternative to the traditional tracer-based method if care is taken to avoid spurious data and multiple datasets are used to compute a distance-weighted average or other appropriate measure that represents reach-averaged conditions.     

赣西袁水坳陷卡林型金矿床地质特征

赣西卡林型金矿受地层层位及构造控制,呈层状、似层状及透镜状产出。规模为中小型。金矿化与硅化、黄铁矿化及有机碳关系密切。主成矿温度平均150℃左右,成矿压力为247×105Pa～608×105Pa。成矿流体是以大气降水为主的热卤水。     

松散沉积物的结构特征及其环境意义

通过对淮北煤田临涣,宿县矿区新生界底部含水碎屑物质结构特征研究,初步得出结论,组成该层的主要碎屑物质的结构成熟度较低,石英砂粒具有贝壳状断口,锯齿状棱脊,撞击痕及溶蚀和沉淀等表面结构特征,反映了物源区遭受的物理风化作用以及短距离内快速搬运的沉积特征。     

我国东南部夏季干旱指数研究

根据中国东南部夏季降水与气温显著负相关的特点, 选用合适的干旱指数分析了旱涝的时空变率.得到的4个空间型较之降水分型结构简单, 又综合反映气候异常状态.时间演变没有显著的长期倾向.干旱指数场与850 hPa U、V等场奇异值分解 (SVD) 分析得到, 南海至菲律宾西风偏强, 中国东部南风分量偏强, 副高南 (北) 侧东 (西) 风偏强时, 长江中下游偏旱, 反之则偏涝.     

山西省塔儿山—二峰山地区破碎带型金矿地质特征及找矿标志

通过找工作的实践,证实塔儿山－二峰山财区金矿体产于破碎带内,并认为破碎带构造复杂,硅化,黄铁矿,褐铁矿化,蚀度强裂地段是找金矿的重要标志。