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长江口启东嘴潮滩沉积速率变化及环境意义 被引量:4
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作者 张云峰 张振克 +1 位作者 任航 陈影影 《海洋湖沼通报》 CSCD 北大核心 2018年第4期36-43,共8页
沉积速率是认识潮滩沉积地貌环境变化的重要环境指标。长江口启东嘴潮滩位于长江北支沿江岸线和江苏沿海岸线的交汇处,是典型的粉砂淤泥质潮滩。对采集的岩芯沉积物QDZ-1进行了^(137)Cs同位素测年和粒度分析。结果表明岩芯沉积物以粉砂... 沉积速率是认识潮滩沉积地貌环境变化的重要环境指标。长江口启东嘴潮滩位于长江北支沿江岸线和江苏沿海岸线的交汇处,是典型的粉砂淤泥质潮滩。对采集的岩芯沉积物QDZ-1进行了^(137)Cs同位素测年和粒度分析。结果表明岩芯沉积物以粉砂为主,从底部到表层表现为由粗变细的趋势,符合粉砂淤泥质潮滩的沉积特征。多年平均沉积速率在1963—1986年为2.61cm/a,在1963—2011年为1.82cm/a,在1986—2011年为1.10cm/a。基于此,对环境变化的意义进行了进一步解释。在深度172.5cm处砂含量突然增加,根据沉积速率估算,可能是长江流域1931年洪水等极端环境变化的影响。自从大规模引种互花米草后,保堤促淤效果显著,潮滩地貌由侵蚀转变为淤积,随着潮滩的逐渐淤高,由低潮滩转变为高潮滩,沉积速率呈现逐渐下降的趋势。 展开更多
关键词 长江口 启东嘴潮滩 沉积速率 137Cs测年 环境变化
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Source Rock Potential and Organic Geochemistry of Carboniferous Source Rocks in Santanghu Basin, NW China 被引量:6
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作者 宋到福 何登发 王书荣 《Journal of Earth Science》 SCIE CAS CSCD 2013年第3期355-370,共16页
Carboniferous source rocks identified by drilling in Santanghu (三塘湖) Basin were evaluated for their source potential, employing organic geochemistry and RockEval pyrolysis. The organic matter origin and depositio... Carboniferous source rocks identified by drilling in Santanghu (三塘湖) Basin were evaluated for their source potential, employing organic geochemistry and RockEval pyrolysis. The organic matter origin and depositional environment of these samples were also determined through biomarker analysis. Most of the Carboniferous source rocks in Santanghu Basin are characterised by high values of total organic carbon (TOC) content and high extractable organic matter content and hydrocarbon yields, indicating that they are organicrich source rocks with high oil generative potential. The organic matter is predominantly Type I and Type II kerogen with a minor contribution of Type III kerogen, as demonstrated by its pyrolysis parameters and carbon isotope values. According to Ro (%) and T max values, most of the studied samples are at earlyto middle-thermal mature stage; only a few of the samples are at a highly mature stage (past peak oil generation). The biomarker analysis reveals a dominance of algal/bacterial organic matter input, with a minor contribution of land plant material. Pr/Ph ratio supports a suboxic depositional condition, consistent with a neritic or marine-continental alternating environment proposed by predecessor. 展开更多
关键词 Santanghu Basin Carboniferous source rock hydrocarbon potential depositional en- vironment organic geochemistry.
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Mapping of ionospheric parameters for space weather predictions: A concise review
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作者 Y. KAMIDE A. IEDA 《Science China(Technological Sciences)》 SCIE EI CAS 2008年第10期1589-1599,共11页
Reviewing briefly the recent progress in a joint program of specifying the polar ionosphere primarily on the basis of ground magnetometer data, this paper em-phasizes the importance of processing data from around the ... Reviewing briefly the recent progress in a joint program of specifying the polar ionosphere primarily on the basis of ground magnetometer data, this paper em-phasizes the importance of processing data from around the world in real time for space weather predictions. The output parameters from the program include ionospheric electric fields and currents and field-aligned currents. These real-time records are essential for running computer simulations under realistic boundary conditions and thus for making numerical predictions of space weather efficient as reliable as possible. Data from individual ground magnetometers as well as from the solar wind are collected and are used as input for the KRM and AMIE mag-netogram-inversion algorithms, through which the two-dimensional distribution of the ionospheric parameters is calculated. One of the goals of the program is to specify the solar-terrestrial environment in terms of ionospheric processes and to provide the scientific community with more than what geomagnetic activity indices and statistical models indicate. 展开更多
关键词 IONOSPHERE magnetogram INVERSION GROUND magnetic data space WEATHER solar-terrestrial en- vironment
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