多光谱遥感的盐类预测模型在莎车盆地找钾中的应用

石膏和盐类矿物的实测光谱特征表明,石膏反映在ASTER图像631(ETM图像743)假彩色合成图上呈现浅天蓝色调,而石盐为弱粉红色的色调特征。文章在此基础上利用主成分分析提取了石膏与盐类矿物的信息。野外查证结果显示,本次提取的信息与实际地物对应良好,并且在野外查证中新发现了一处含钾石盐层,根据遥感信息推测喀什西南凹陷区(文中D区)为找钾的预测区。     

高密度电法在宝兴县草坪鞋石膏矿勘查中的应用

通过对四川宝兴县草坪鞋石膏矿区开展高密度电法工作,经采对数据的处理及地质解释,发现了石膏工业矿层及分布状态,取得了较好的地质效果。     

牛热四井膏泥岩钻井液技术

牛热四井位于河北省固安县牛驼镇,钻井施工中在下第三系钻遇厚度达300 m的膏泥岩地层,通过加强钻井液质量管理,使用铁铬盐、CMC、磺化沥青、聚丙烯酸钾、火碱等处理剂调节钻井液性能,成功地解决了膏泥岩地层遇水膨胀垮塌的问题,在膏泥岩钻井液技术方面积累了宝贵的经验。     

S/D-2井欠饱和盐水钻井液技术

S/D-2井在井深2480 m以后钻遇了大段复杂的盐膏层,由于盐的溶解而造成井径扩大及盐析而结晶造成卡钻。针对上述问题,应用了聚磺欠饱和盐水钻井液体系,解决了钻遇盐膏层后的井壁失稳、钻井液污染等技术问题。详细介绍了该井聚磺欠饱和盐水钻井液的应用技术。     

东营凹陷深层烃源岩生物标志物特征及其意义

主要利用GC-MS分析方法,对东营凹陷北部膏岩层以及上下两段深层烃源岩可溶有机质中正构烷烃、幽烷类和藿烷类生物标志化合物进行了分析,通过各种化合物的组成和分布特征对其地球化学意义进行了探讨.结合各项参数结果表明:三段有机质来源都具有低等水生生物输人和陆源高等植物输人的双重特征,膏岩层上段与下段有机质来源相似,以陆源物质...     

Quantitative evaluation of strategies for erosion control on a railway embankment batter

Strategies for erosion control on a railway embankment batter (side slope) are quantitatively evaluated in this paper. The strategies were centred on control (‘do nothing’ treatment), grass seeding, gypsum application, jute mat (an erosion control blanket) placement and planting hedgerows of Monto vetiver grass. Rainfall and runoff were monitored at 1 min intervals on 10 m wide embankment batter plots during 1998 and 1999. Total bedload and suspended sediment eroded from the plots were also measured but only for a group of storm events within sampling intervals. It has been demonstrated that vetiver grass is not cost‐effective in controlling erosion on railway batters within Central Queensland region. Seeding alone could cause 60% reduction in the erosion rate compared with the control treatment. Applying gypsum to the calcium‐deficient soil before seeding yielded an additional 25% reduction in the erosion rate. This is the result, primarily, of 100% grass cover establishment within seven months of sowing. Therefore, for railway embankment batter erosion control, the emphasis needs to be on rapid establishment of 100% grass cover. For rapid establishment of grass cover, irrigation is necessary during the initial stages of growth as the rainfall is unpredictable and the potential evaporation exceeds rainfall in the study region. The risk of seeds and fertilizers being washed out by short‐duration and high‐intensity rainfall events during the establishment phase may be reduced by the use of erosion control blankets on sections of the batters. Accidental burning of grasses on some plots caused serious erosion problems, resulting in very slow recovery of grass growth. It is therefore recommended that controlled burning of grasses on railway batters should be avoided to protect batters from being exposed to severe erosion. Copyright © 2001 John Wiley & Sons, Ltd.     

Fractionation of hydrogen and oxygen isotopes of gypsum hydration water and assessment of its geochemical indications

Fundamental knowledge of the isotopic fractionation between the hydration water and the mother solution and whether the primary information recorded in hydration water can be preserved or not in deposits or mines have long been unclear. In order to calculate the accurate hydrogen and oxygen isotopic fractionation factors between gypsum hydration water and its mother solution with new methods, to understand the mechanism of fractionation and synthetically assess the record-keeping abilities of the isotopic composition of hydration water during the process of diagenesis after deposition, experiments on the hydrogen and oxygen isotopic compositions of gypsum hydration water and its mother solution at different isothermal temperatures from 5 to 50°C were systematically conducted. In addition, samples from two typical gypsum deposits formed in different environmental conditions were also determined. Results show that during gypsum crystallisation, both hydrogen and oxygen isotopes show significant fractionation between the hydration water and the mother solution. The calculated hydrogen isotopic fractionation factors are <1, while the oxygen isotopic fractionation factors are >1 at temperatures from 5 to 50°C. The fractionation factors show no functional relationships with temperature. Isotopic compositions of gypsum hydration water in arid lake sediments can be used to trace the source of water and primary deposit environmental information. However, the isotopic composition of the gypsum hydration water can easily be altered by dissolution and secondary precipitation of gypsum during later diagenesis, particularly in areas with humid climate and abundant groundwater. A very careful assessment on record-keeping abilities of the primary isotopic composition of hydration water in gypsum during later diagenesis must be considered before application.     

Origin of aragonite in a continental saline seep,north Queensland

Aragonite, low‐magnesian calcite, gypsum and halite were identified by X‐ray diffraction and electron microbeam techniques in mineral precipitates near a salt seep 50 km southwest of Charters Towers in north Queensland. The chemistry of water from the creek and from the groundwater at the salt seep shows that Mg:Ca ratios are greater than or equal to 1.5 throughout the year. The formation of halite and gypsum is due to evaporative concentration of the water at the seep and that of the carbonates, in particular aragonite, is probably due to a combination of evaporation and photosynthetic activity by diatoms.     

Evolution of karst in Messinian gypsum (Monferrato,Northern Italy)

In the Tertiary Basin of Piedmont (Northern Italy) a 100-150 m thick Messinian sedimentary succession crops out, composed of pre-evaporitic clays, gypsum beds and post-evaporitic lacustrine-marine fine-grained sediments. In the Monferrato area the thickness of the evaporite sequence is highly variable (0-140 m) due to an important erosion surface formed at the end of the evaporite cycle and carved in the gypsum beds. Epigenic caves probably formed during this short intra-Messinian phase of emersion. Cave sediments contain benthonic and planctonic foraminiferal associations ranging in age from Burdigalian to Upper Pliocene. These sediments have probably been deposited in recent times, although it cannot be completely ruled out that they accumulated in caves developed in Upper Messinian times. The formation of the most important caves of this area probably started at the end of the Messinian under epigenic conditions. Possibly, those inherited caves enlarged slowly during the Quaternary in an intrastratal and confined hypogene karst system.     

山东省平邑玉荣石膏矿“12·25”事故救援过程中的水文地质问题分析

山东平邑凹陷盆地内石膏资源丰富,自20世纪80年代起,区内石膏开采持续不断,随着开采范围的不断扩大,形成了大面积采空区,地面塌陷时有发生。2015年12月25日,平邑县玉荣石膏矿、万枣石膏矿范围内发生大面积塌陷,造成29名矿工被困。在施救过程中,遇到诸多水文地质问题,如灰岩含水岩组富水性增强;矿坑水补给条件改变;膏上灰岩岩溶水对采空区的大量补给;矿区南侧老窿水的威胁和岩溶塌陷等,直接影响了救援工作的顺利开展。针对在救援过程中出现的以上问题进行了综合分析研究,总结了救援过程中采取的多种防治措施和经验及教训,为同类矿山事故救援提供一定借鉴。