我国淡水湖泊资源开发探讨——以东平湖为例

本文阐述了我国淡水湖泊具有调节河川径流、发电、灌溉、航运等功能。并以东平湖为例,系统论述了它们的资源特征(自然环境、理化特征、鱼类生境、旅游环境),及其利用开发现状,并分级分析了它们各自的生态环境、生态系统特点。指出了我国淡水湖泊存在的主要问题:入湖水源不足,工业废污水的污染,水工建筑物阻隔河湖通道,滞洪淤积等,导致了水域生态环境恶化,溯河入湖物种绝灭,湖体湮废等。最后提出了设计湖体水生资源得以开发的流域水资源调节控制规划;加强流域水土保持;有计划地进行湖底清淤;疏竣河湖接口通道,添建鱼道;编制利于水生动、植物生境的水利工程运营方案,设计高效静水资源开发方案等整治对策。

银额盆地查干断陷闭流湖盆层序类型与层序地层模式

目前,对断陷畅流湖盆的层序地层模式研究较多,而针对断陷闭流湖盆的层序地层模式研究较少。以查干早白垩世断陷闭流湖盆为例,分析了断陷闭流湖盆的沉积特征和演化规律,总结了断陷闭流湖盆的层序类型及特征,提出了断陷气候复合型和气候型层序类型,归纳了不同演化阶段的层序地层模式。认为查干断陷闭流湖盆沉积演化经历了断初、断陷和断坳等3个阶段,断初和断陷阶段的层序地层模式是一种由断陷气候复合型层序组成的层序地层模式,断坳阶段的层序地层模式是由气候型层序组成的层序地层模式。

银额盆地查干断陷闭流湖盆层序的控制因素与形成机理

陆相层序的控制因素与形成机制是陆相层序地层学研究的一项重要内容。断陷闭流湖盆作为一种独特的类型有其自身的特点。对查干凹陷早白垩世断陷闭流湖盆的沉积演化和基准面相对变化曲线的研究表明查干凹陷断陷闭流湖盆层序的控制因素以构造控制因素与气候因素占主导地位 ,其次是沉积物供应速率和湖平面的变化 ;在造控制因素与气候因素的双重控制下形成两类层序 ,一类是断陷气候复合型层序 ,另一类为气候型层序。

微电阻率扫描成像测井在沉积环境识别中的应用

利用FMI成像资料进行沉积相分析,特别之处是能够对地层进行长井段连续的观察和描述,获得丰富的岩性、层理、剖面旋回等重要的岩石结构和沉积构造方面的信息,而相分析的具体方法与常规地质分析完全相同。本井FMI测量井段自下而上为上奥陶统五峰组、下志留统龙马溪组与小河坝组底部地层。通过成像测井分析认为上奥陶统五峰组为灰黑色粉砂质泥岩,含笔石化石,为水流不畅的停滞盆地沉积。下志留统龙马溪组下部为灰黑色粉砂质泥岩、泥岩以及黑灰色泥、页岩、粉砂质泥页岩,含笔石化石,为停滞盆地沉积;龙马溪组中部为黑灰色、灰色泥质粉砂岩、粉砂岩夹粉砂质泥岩、泥岩,泥岩发育水平层理,泥质粉砂岩、粉砂岩发育变形构造、块状层理,底部见冲刷面,为浊流沉积;龙马溪组上部为深灰色及灰色泥岩夹粉砂质泥岩、薄层粉砂岩,泥岩发育水平层理,见变形构造、包卷层理,为浅海陆棚夹浊流沉积。FMI测量小河坝组底部为灰色泥岩、粉砂质泥岩,为浅海陆棚沉积。

柳林泉域滞流区岩溶水的热源及其Na^+、Cl^-来源探讨

柳林泉域滞流区岩溶水以高温、高Na^+和Cl^-浓度为主要特征。文章在区域地质及水文地质条件分析基础上,采用化学计量学原理,判断了该区岩溶水的热源及Na^+和Cl^-的来源。结果显示:在泉域的补给区、径流区和排泄区的上青龙、龙门会、杨家港和寨东泉组,岩溶水中的Na^+和Cl^-主要来源于岩盐的溶解,其中多余的Na^+可能来自于阳离子交换、黄土中含Na^+矿物的溶解及城市污水的排放;滞流区和排泄区的刘家疙瘩泉组岩溶水中高浓度的Na^+和Cl^-也主要来自于岩盐的溶解,而多余的Cl^-可能由岩溶水中的Na^+交换吸附介质中的Ca^(2+)或Mg^(2+)所致。西部滞流区岩溶水的热源主要包括地温梯度增热、当地正常地温、岩石中放射性元素产热和石膏的溶解放热,其贡献率分别为45%、28%、20%和7%。

基于二维和三维模型的盆地典型剖面流场对比

前人多在二维剖面上分析盆地地下水循环规律,基于二维剖面模型和三维模型得到的剖面地下水流场是否一致值得探究。推导了三维单元盆地和复杂盆地的水头解析解,选取了水位最高点到最低点的剖面作为典型剖面,比较了二维、三维模型得到的典型剖面流场。当潜水面起伏关于典型剖面对称时,与三维模型相比,单元盆地二维剖面模型得到的流量随深度衰减偏慢,复杂盆地二维剖面模型得到的内部驻点位置偏深。当潜水面起伏不对称时,由于存在垂直于典型剖面的流速分量,典型剖面上不存在内部驻点,滞流区仍然存在。结论加深了对地下水在三维空间循环规律的认识。

Upwelling current and its relationship to the enrichment of organic matter in the Lower Silurian Longmaxi Formation,northern Chongqing-western Hubei area,southern China

Upwelling currents play a crucial role in the enrichment of organic matter,yet the mechanisms driving this process remain incompletely understood due to methodological and data resolution limitations.In this paper,we employ a combination of biostratigraphic classification,qualitative methods,and quantitative methods to systematically analyze the sedimentological and geochemical characteristics of the Lower Silurian Longmaxi Formation in the northern Chongqing-western Hubei area,southern China.The relationship between the upwelling currents and organic matter enrichment in the shale of the Longmaxi Formation is investigated.Results indicate that the upwelling currents in the study area were primarily influenced by the foreland flexure process.From the Rhuddanian(flexure-sedimentation stage)to the Aeronian(flexure-migration stage),the more intense tectonic activity led to gradual opening of the barrier between the South Qinling Ocean and the Yangtze Platform,resulting in an increase in the influx of the oceanic current.The upwelling currents significantly contributed to the organic matter production,albeit without substantially affecting the preservation conditions.Throughout the succession of the Longmaxi Formation,the organic matter content decreased gradually from the passive continental margin to the foreland flexural stagnant basin,which was mainly due to deterioration of the preservation conditions as a result of sea level fall and increased terrigenous input.Despite the increase in the upwelling currents,they did not decisively control the organic matter enrichment.Spatially,during the Rhuddanian to Aeronian period,the organic matter content decreased similarly from the passive continental margin to the foreland flexural stagnant basin,influenced by reduced organic matter production caused by weakening of the upwelling currents and the worsening preservation conditions caused by sea-level fall.The terrigenous input had a relatively minor impact.The results of this study provide new insights into the role of upwelling currents in the organic matter enrichment within the Longmaxi Formation,overcoming previous methodological and resolution barriers.