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991.
东营凹陷旋回式深湖相烃源岩研究 总被引:28,自引:6,他引:28
对东营凹陷沙河街组烃源岩的研究发现:在灰褐色泥岩、纹层状褐色泥岩、钙质泥岩和油页岩中常常夹有泥质粉砂岩和少量浊积砂岩;对牛38井密集采样分析则指示有机碳含量等多项地球化学参数呈现出“波峰”、“波谷”状变化特征,沉积界面也清晰地记录了湖平面的旋回式(升降)变换过程。本文探讨了盆地的充填过程,建立了旋回式深湖相沉积的地层模式——平衡充填,并深入分析了该套烃源岩的地质地球化学特征和有机质的赋存状态,指出旋回式深湖相烃源岩与浊积砂和前三角洲砂体主要以交互式或包裹式构成最佳生储配置关系,有利于隐蔽油气藏的形成。 相似文献
992.
罗布泊地区罗北凹地潜卤水钾矿床成因与开发前景 总被引:7,自引:1,他引:7
罗北凹地潜卤水钾矿床位于新疆罗布伯地区北部,是一个大型的综合性盐类矿床,以潜卤水钾矿为主,伴生有液体NaCl、MgCl2和固体石盐、钙芒硝。罗布伯盐湖周边基岩山区富钾花岗岩和火山岩、塔里木盆地古盐矿床和罗布伯北部中更新统化学沉积物形成的台地等为罗北凹地潜卤水矿床提供了丰富的物源物质条件,而半封闭的构造成环境和干旱气候条件是其形成的有利条件。与世界著名盐湖比较,罗北凹地潜卤水钾矿的K^ 含量、储量及其化学成分具有独特优势,而钾肥是中国的紧缺产品,需求量不断增加,因此,罗北凹地潜卤水钾矿床具有较好的开发前景。 相似文献
993.
东平湖是在南水北调东线工程中起调蓄、输水的枢纽,其水质关系到东线工程供水目标的成败,要保持好水体水质,必须强化入湖水体水质的监测。 相似文献
994.
青海高寒湖沼景观区风成沙对成矿元素迁移的扰动机制的研究 总被引:5,自引:0,他引:5
青海高寒湖沼景观区是风成沙沉降区,由于风成沙的干扰,水系沉积物-0目的粒级段多数元素异常大幅度降低,甚至消失.研究表明,风成沙扰动层的元素分维呈现突变特征.根据固定沙丘和流动沙丘优势粒级混合扰动特征,计算了粒级因素系数,试验结果说明粒级因素系数可以较好地描述风成沙混入量特征.用突变理论的折叠突变势函数公式,计算了组分扰动因素系数,计算结果与扫面试验结果非常吻合.高寒湖沼景观区域化探采样介质以-4(或-10)~+40目为宜. 相似文献
995.
Analysis of the Major Fe Bearing Mineral Phases in Recent Lake Sediments by EXAFS Spectroscopy 总被引:1,自引:0,他引:1
Extended X-ray absorption fine structure (EXAFS) spectroscopy and chemical analyses were combined to determine the Fe bearing minerals in recent lake sediments from Baldeggersee (Switzerland). The upper section of a laminated sediment core, deposited under eutrophic conditions, was compared to the lower part from an oligotrophic period. Qualitative analysis of FeK EXAFS agreed well with chemical data: In the oligotrophic section Fe(II)–O and Fe(III)–O specieswere present, whereas a significant fraction of Fe(II)–S sulfides was strongly indicated in the eutrophic part. A statistical analysis was performed by least square fitting of normalized reference spectra. The set of reference minerals included Fe(III) oxides and Fe(II) sulfides, carbonates and phosphates. In the oligotrophic regime no satisfying fit was obtained using the set of reference spectra, indicating that siderite (FeCO3) was not present in a significant amount in these carbonate-rich sediments. Simulated EXAFS spectra for a(Cax, Fe1-x)CO3solid solution allowed reconstructing the specificfeatures of the experimental spectra, suggesting that this phase was the dominant Fe carrier in the oligotrophic section of the core. In the eutrophic part, mackinawite was positively identified and represented the dominant Fe(II) sulfide phase. This finding agreed with chemical extraction, which indicated that18–40 mol% of Fe was contained in the acid volatile iron sulfide fraction. EXAFS spectra of the eutrophic section were best fitted by considering the admixture of mackinawite and the Fe–Ca carbonate phase inferred to be predominant in the oligotrophic regime. 相似文献
996.
As a useful approach for hydrocarbon exploration,the sequence stratigraphy has been commonly accepted.The concepts of sequence and parasequence provide a state-of -the-artframe-work for studying the distribution and characters of depositional system,and analyzing the occurrence,distribution,characteristics of source,reservoir and seal-play elements.The newly-developed geochemical -sequence stratigraphy focuses mainly on the occurrence,distribution and characters of source rocks and reservoir hydrocarbons within a chronostratigraphic framework,Integrated with sequence wtratigraphy,geochemistry can be used to study the surce rock potential within a sequence wtratigraphic framework and to describe the characteristics of hydrocarbons accumulated in reservoirs,which were predicted by way of sequence stratigraphy.The concept of geochemical-sequence wtratigraphy was proposed by Peters et al.(2000).Constructing a reliable sequence stratigraphic framework is the basis of geochemical-sequence wtratigraphic study although it is not the main goal.High-resolution biomarker analysis is critrical to the construction of a geochemical-sequence stratigraphic model.The geochemical-stratigraphic study involves mainly:(1) the distribution and geochemical characteristics of source rocks with relative sea (lake)-level change;(3) to prodict if these reservoirs bear hydrocarbons and their geochemical features;(4) to be used to construct the time-stratigraphic framework.This paper also summarizes the lake basin types,and introduces their facies associatons,source potential and organic geochemical features.At the end,the authors offer some suggestions about how to carry out geochemical-sequence stratigraphic study in ladcustrine strata. 相似文献
997.
998.
999.
盐湖/湖泊是气候变化的一面镜子本文以国内外典型盐湖区地质灾害为案例。说明自然引起的盐湖地质灾害,人类在事先监测而掌握其变化趋势情况下,可趋利避害,减少损失程度。文中分析在中国西部气候可能由暖干向暖湿转型的情势下,中国盐湖的变化趋势,并就其近期湖水涨缩特点划分3种类型(湖水上涨型区、湖水下降型区和湖水上涨不稳区)。为了适应中国盐湖区气候一湖泊变化,提出在重要盐湖区增建和完善水文、气象观察站,并与遥感监测相结合;建立多学科、跨部门的近期西部盐湖区环境变化的重大基础项目。同时需在重点盐湖区增设防洪防旱水利设施工程、制定湖区生态保护措施等,在筑建盐田和基建工程时应充分考虑洪水泛滥的影响。 相似文献
1000.