Petrography and geochemistry of septarian carbonate concretions from the Boom Clay Formation (Oligocene,Belgium)

The septarian carbonate concretions from the Boom Clay (Belgium) consist mainly of authigenic minerals such as micrite ( 70% bulk volume) and pyrite framboids ( 3%). These mineral phases occur between detrital grains and fossils. The septarian cracks are lined with calcite, which is sometimes covered with pyrite. The preservation of delicate sedimentological features in the concretion matrix (hardly compacted faecal pellets, burrows and uncrushed shells) points to an early origin of the concretions. Systematic geochemical variations from concretion centre to edge suggest that growth continued during shallow burial. The13C values (–17.5 to –20.5) of the concretionary carbonate show that bacterial sulphate-reduction processes were dominant. Sulphate-reduction-derived HCO3- was diluted by marine-related HCO3-, derived from dissolved bioclasts. A slight enrichment in 13C during growth is caused by the decreasing influence of sulphate reduction because of the progressive closure of the diagenetic system due to shallow-burial compaction. The 18O values (–0.5 to +1.0) of the concretionary carbonate point to a marine origin. The slightly 18O-depleted signature with respect to time-equivalent marine-derived carbonate relates to the incorporation of an 18O-depleted component, originating from sulphate and organic matter. The slight decrease in 18O during growth relates to an increasing influence of this component and to a decreasing influence of seawater-derived oxygen during early diagenesis.     

同铁构造嘉陵江组储层裂缝非线性预测与分析研究

基于储层裂缝系统具有非线性特征．应用三种直接与裂缝有关的非线性参数对同铁构造嘉陵江组嘉二^1储层裂缝进行了非线性预测与评价。嘉陵江组嘉二^1储层裂缝空间展布特征是成区带分布，沿构造轴向和断层走向从北到南分为两带一区，并分为四级，这种裂缝展布特征与构造特征、断层及地应力分布密切相关。同铁构造嘉陵江组嘉二^1储层有效裂缝富集区与天然气富集区具有对应关系，并为钻探所证实，为同铁构造嘉陵江组嘉二^1气藏的开发提供了科学依据，具有重大的经济意义。     

黔阳地区农业地质背景与农业优势区分析

为了扩大区域地质调查成果的服务领域，通过地层岩石、地质构造、地貌、水文地质、地球化学背景及气候等因素的综合分析，结合农、林、果、药作物及畜牧渔业的生产状况，将黔阳地区划分为：橙桔机、优质稻、林、林桔橙、板栗林、林茶7个优势区。对合理调整农业生产结构，建设名优特农产品基地等具有重要作用。     

农业地质及其开发利用

农业是人类基本生活资料的主要来源，是国民经济发展的基础，制约着其他产业部门发展的速度和规律。中国是农业大国，但却不是农业强国，农业地质主要研究与农业有关的岩石，地貌，地球化学，水资源等地质条件，农业地质与农业生产息息相关，并为农业生产的良好发展提供依据。     

对岩浆岩成矿性判别指标的探讨

岩体是否成矿的根本原因是所含成矿元素丰度的高低。岩体形成什么矿产则受不同岩类所含成矿元素种类的制约。显然，岩石类型仅起储存成矿元素的载体作用。据此，笔者以成矿元素丰度为依据，首创了岩体成矿指数等１１种成矿性判别的最佳定性指标。     

未熟有机质发酵后

采用对未熟有机质富集培养本源菌再进行类发酵(Eh>-300mV)的模拟实验方法,重点研究了发酵样品中某些生物标志化合物的变化,探讨了在低演化阶段,由于细菌对有机质的参与和改造,液态烃类形成的地球化学特征。样品发酵后,烃类,尤其是低相对分子质量烃类含量增加,CPI和OEP值接近或略高于1。族组成中,沥青质含量减少,烃类和非烃增加。饱和烃中,C-13位上带有正烷基侧链的三环萜烷出现;高含量的伽马蜡烷被检出;生物构型藿类化合物向地质构型藿烷转化,C-22位上立体异构化平衡参数明显增大,接近或达到异构化终点值;单芳甾类烃与三芳甾类烃共存;甾体化合物含量的总体趋势是相对贫乏,平衡参数较低。     

元素赋存状态研究对于矿产资源勘探开发之重要意义

地球系统中元素的赋存状态即为元素的质的属性。在地质生产及科研工作中，注重元素量的属性同时，必须研究元素质的属性。这样不仅可以取得更准确的矿产资源信息，还可以指导确定最佳的开采，选冶方案，使有限的矿产资源得到最科学合理的利用。     

IAEA和中国的硫同位素参考物质的δ~(33)S、δ~(34)S值与~(32)S/~(33)S、~(32)S/~(34)S绝对比值

用六氟化硫法对IAEA S 1、IAEA S 2、IAEA S 3、IAEA SO 5、IAEA SO 6、GBW 0 44 14和GBW 0 44 15的δ3 3 S、δ3 4 S值进行了测定。用人工配制的同位素混合物和六氟化硫法对IAEA S 1、IAEA S 2、IAEA S 3和GBW 0 44 14、GBW 0 44 15的3 2 S 3 3 S、3 2 S 3 4 S绝对值进行了标定。其结果对IAEA硫同位素系列参考物质的定值起到了关键作用。