渤海湾盆地渤中凹陷西南环古生界沉积微相及其对岩溶储集层的控制作用*

渤海湾盆地渤中凹陷西南环古生界深埋碳酸盐岩潜山天然气获得重大突破,钻井资料揭示该地区碳酸盐岩岩溶储集层具有很强的非均质性。由于沉积相是岩溶储集层发育的主控因素之一,因此文中根据岩心和薄片资料、测井相、微量元素和古生物特征等多种手段综合分析沉积相特征。结果表明,研究区现存奥陶系纵向上表现为1个较为完整的海退— 海进序列,主要发育开阔台地和局限台地2种沉积亚相,并可进一步划分为台内滩、滩间、潮下带和潮间带4种沉积微相。台内滩和潮下带微相横向分布连续稳定,水动力条件强,形成的储集层早期溶孔发育,且这2种沉积环境里发育的碳酸盐岩较纯净,经后期风化淋滤形成的岩溶储集层厚度大、质量好,因此是有利的岩溶储集层发育相带。该研究明确了研究区台内滩及潮下带的发育特征,对下一步油气勘探具有一定的指导意义。     

Structural changes of humic acids from sinking organic matter and surface sediments investigated by advanced solid-state NMR: Insights into sources, preservation and molecularly uncharacterized components

Knowledge of the structural changes that particulate organic matter (POM) undergoes in natural systems is essential for determining its reactivity and fate. In the present study, we used advanced solid-state NMR techniques to investigate the chemical structures of sinking particulate matter collected at different depths as well as humic acids (HAs) extracted from these samples and underlying sediments from the Saguenay Fjord and the St. Lawrence Lower Estuary (Canada). Compared to bulk POM, HAs contain more non-polar alkyls, aromatics, and aromatic C-O, but less carbohydrates (or carbohydrate-like structures). In the two locations studied, the C and N contents of the samples (POM and HAs) decreased with depth and after deposition onto sediments, leaving N-poor but O-enriched HAs and suggesting the involvement of partial oxidation reactions during POM microbial degradation. Advanced NMR techniques revealed that, compared to the water-column HAs, sedimentary HAs contained more protonated aromatics, non-protonated aromatics, aromatic C-O, carbohydrates (excluding anomerics), anomerics, OC_q, O-C_q-O, OCH, and OCH₃ groups, but less non-polar alkyls, NCH, and mobile CH₂ groups. These results are consistent with the relatively high reactivity of lipids and proteins or peptides. In contrast, carbohydrate-like structures were selectively preserved and appeared to be involved in substitution and copolymerization reactions. Some of these trends support the selective degradation (or selective preservation) theory. The results provide insights into mechanisms that likely contribute to the preservation of POM and the formation of molecules that escape characterization by traditional methods. Despite the depletion of non-polar alkyls with depth in HAs, a significant portion of their general structure survived and can be assigned to a model phospholipid. In addition, little changes in the connectivities of different functional groups were observed. Substituted and copolymerized carbohydrates and fused-ring aromatics detected in the present study likely represented an important part of molecularly uncharacterized components (MUC).     

宁芜盆地凹山铁矿床辉长闪长玢岩和花岗闪长斑岩的锆石U-Pb年龄及其地质意义

宁芜盆地是长江中下游多金属成矿带的重要矿集区之一,是玢岩型铁矿成矿模式建模的基地.玢岩型铁矿床成矿时代的约束对区域成岩成矿作用及成矿动力学背景研究具有重要的意义.凹山铁矿床是宁芜盆地玢岩型铁矿床的典型代表之一,本文选择矿区发育的两种与成矿作用关系密切的岩浆岩为研究对象,进行锆石LA-MC-ICP-MS U-Pb年代学研...     

大气降水热液成矿——西秦岭某硅、灰、泥岩型铀矿床成矿模式探讨

西秦岭某硅、灰、泥岩型层控铀矿床是在矿源层(中志留统)的基础上,由地下水热液渗滤改造而成。铀的工业富集发生在矿源层褶皱成陆之后,成矿高峰则发生在中、新生代交替时期。成矿溶液是受大气降水补给的地下水热液;成矿物质主要来自矿源层本身。矿源层长期遭受地下水热液作用,溶液中大量的铀酰离子形成稳定的碳酸铀酰络合物,并被运移至岩性和构造的圈闭部位,通过吸附和共沉淀等作用富集,或通过还原、水解和过饱和沉淀等作用形成沥青铀矿或再生铀黑。该层控铀矿床的整个成矿过程具有典型的逐级增量特点,属于塔式累积成矿的基本模式,后生富集是成矿的关键。     

巴音戈壁盆地中南部中新生代构造-沉积演化对铀成矿的制约及找矿预测

[研究目的]巴音戈壁盆地中新生代主要经历了早白垩世断陷、断坳转折以及晚白垩世坳陷发育阶段,多期次构造改造对铀成矿的制约尚不清晰,影响下一步的找矿预测工作.[研究方法]本文选择盆地中南部凹陷带为研究区,综合以往成果认识与地质剖面对比研究,系统研究了凹陷构造样式、构造演化对沉积充填的影响.[研究结果]在早白垩世中晚期、晚白...     

利用雷达回波与GIS技术反演面雨量研究

自动气象站可以直接测量单点或较小范围的降水量,测量精度较高,但自动气象站的分布密度不够,往往漏掉强降水、暴雨中心。雷达能实时探测云和降水结构及系统发生、发展演变情况,能迅速提供一定区域的实时降水情况,但雷达测量误差较大,测定局地降水量精度不高,因此,将自动气象站与雷达进行点面结合,采用一定的数学方法和GIS技术,可以得到能够代表某特定区域平均降水情况的面雨量。以深圳市行政区域面雨量反演为例,建立区域内所有测站的6 min累积降雨资料与雷达回波数据之间的回归关系,借助GIS技术和包括对经度、纬度、海拔高度3个因子的地理订正,构建雷达图上特定行政区域的面雨量计算模型,并对格点拟合雨量进行空间分辨率的精细化反演,得到雷达图上的特定行政区域的面雨量图。     

焦耳效应标定高温卡尔维微量热计

根据热流式量热计的Tian氏方程,用焦耳效应标定高温卡尔维微量热计。用偏差法得到的灵敏度值与积分法测得的值一致。用回归曲线对灵敏度实验值进行拟合,利用计算机求得灵敏度—温度回归曲线,得到了室温至700℃的全部灵敏度值,从而即可使用微量热计测量此温度范围内的未知样品热效应。     

云南澜沧老厂矿区影像线-环结构矿床定位模式研究

文章通过对老厂地区TM影像线性构造、环形构造和蚀变信息的解译分析,综合矿床地质、地球物理和地球化学等特征,总结了老厂线-环结构的矿床定位模式。南北轴向的南老环和东西轴向的透镜体系列分别反映了华力西期火山洼地和燕山期—喜马拉雅期隐伏中酸性岩体,两者叠加形成老厂环-环横叠式结构,与隐伏岩体同期或稍后的NW向、NE向共轭线性构造带与环形构造叠加交切,多组构造的交汇点是有利的成矿部位。遥感影像上大面积的色调异常斑块显示了近矿围岩蚀变的范围。基于老厂线-环结构的矿床定位模式,预测了成矿区及近期应勘探的靶区。     

电子探针分析与系列矿物研究

本文论述以电子探针为主要测试手段对下述几种系列矿物的研究成果:(1)铂族元素系列矿物的研究(包括Ru-Os-Fe金属互化物矿物系列和RuAs_2-OsAs_2二元固溶体矿物系);(2)Au-Cu系列矿物的研究;(3)黝铜矿族矿物的研究。