A study on Emei mantle plume activity and the origin of high-As coal in southwestern Guizhou Province     

聂爱国  谢宏 《中国地球化学学报》2006,25(3):238-244

1IntroductionIn recent years deep-going investigations into thestructure of the deep interior of the Earth have provedthat the region of Southwest China where the Emeishanbasalts are widespread is an igneous rock provincecommonly accepted by the internati…  相似文献   

Paleoceanographical records under impact of the Indian monsoon from the Bengal Deep Sea Fan and Ninetyeast Ridge during the last 260 ka     

Fang Nianqiao  Chen Xuefang  Ding Xuan  Hu Chaoyong  Yin Yong  Nie Haogang 《中国科学D辑(英文版)》2001,44(1):351

The orbital and interior climatic cycles can be found both in the Bengal Deep Sea Fan and Ninetyeast Ridge, North Indian Ocean. The periodicity of the Quaternary glacio-eustacy by 100 ka gave a strong impact on the sedimentation in the fan area and the monsoon signals controlled by the obliquity and precession were easily picked up. This paper discusses the possible correlation between the environmental elements on the basis of the ETP phase wheels. A rapid change with short-periods develops during the past 60 ka in the region under study as well. The variability of paleoproductivity has a nonlinear response to the Indian summer monsoon. As contrasted to the Northwest Indian Ocean, here an abundance ofGlobigerina bulloides, a proxy to indicate upwelling current, does not imply so much a promotion of the summer monsoon as its decrease. The record from the ridge area shows in a longer-scale a climatic evolutionary feature corresponding to that of the fan area. A special and great event arising at around 165 kaBP and meaning a catastrophe for ecological environment is reported in this paper. It is also regarded as a result induced by the monsoon.  相似文献   

中国大地测量数据处理进展     

杨元喜吴富梅  聂建亮曾安敏 张丽萍 《测绘科学与工程》2007,27(3):1-7

本文介绍了近四年来中国学者在大地测量数据处理方面的主要进展。重点讨论了抗差估计、粗差探测与可靠性理论、病态条件诊断与正则化、半参数回归与非线性估计等方面的发展。  相似文献   

东胜煤田延安组成煤模式与煤质特征     

聂浩刚  董福辰  孙庆茹 《新疆地质》2013,(3)

总结了东胜煤田延安组煤的两种主要成煤模式,结合煤质分析数据,探讨成煤环境条件对煤质的控制作用。研究结果显示,河流成煤模式的煤层,煤岩类型以暗淡型为主,煤中富丝质组,煤层中矿物质含量较高,灰分含量多大于10%,煤类以不粘煤为主。湖泊三角洲成煤模式的煤层,煤岩类型以光亮煤和半亮煤为主,煤中富镜质组,煤层中矿物质含量低,灰分含量少于10%,煤类以长焰煤为主。经对比两种成煤模式煤的工艺性质,认为富丝质组煤利于气化、动力燃烧、制吸附剂,富镜质组煤则首选液化和配焦。  相似文献   

巴丹吉林沙漠降水稳定同位素特征与水汽再循环          下载免费PDF全文

曹乐  申建梅  聂振龙  孟令群  刘敏  王哲 《地球科学》2021,46(8):2973-2983

了解沙漠降水稳定同位素特征,有助于研究干旱区水循环过程.根据2015-2016年取自巴丹吉林沙漠4个站点的降水样品,分析了δ2H、δ18O的时空分布特征及影响因素;借助后向气团轨迹模型分析了降水水汽来源;采用氘盈余模型计算了水汽再循环比.结果显示,降水δ2H、δ18O均表现出季节效应,夏高冬低;沙漠腹地较外围山区δ2H、δ18O偏正,d-excess偏负,反映出腹地降水的蒸发程度更高.年内降水主要来自西风水汽,夏季部分受东南季风影响.沙漠湖泊区再循环比为10.3%~10.9%,略大于山区的8.5%;再循环水汽在总蒸发量中占比11.1%,反映出沙漠强烈的蒸发对本地降水的贡献较为有限.   相似文献   

南海西南次海盆两侧陆缘中生代晚期构造接触关系          下载免费PDF全文

朱荣伟  姚永坚  刘海龄  徐子英  聂鑫  杜文波 《地球科学》2021,46(3):885-898

为探究南海西南次海盆两侧陆缘地块在中生代晚期构造接触关系及其对南海形成演化的影响,利用过南海西南次海盆两侧陆缘采集的地球物理资料以及公开发表的数据资料,对两侧陆缘的地壳结构及前新生界构造变形特征进行了研究.研究结果显示,西南次海盆两侧陆缘的地壳结构及物质组成存在差异,属于性质不同的两个微地块;两侧陆缘前新生代地层在晚中生代经历了来自不同方向的挤压作用,且遭受抬升剥蚀.结合南海及邻区中生代花岗岩分布特征及区域构造背景,进一步推测两侧陆缘地块在晚中生代以俯冲碰撞的方式完成拼贴缝合,该俯冲碰撞带是南海北部俯冲带在南海西南方向的延伸,并且新生代南海的扩张可能与该俯冲碰撞带这个先存的软弱带有关,是南海海盆初始破裂的部位.   相似文献   

三峡库区仙女山和九畹溪断裂带水库地震变化规律     

王孔伟  路永强  聂进  滕明明  王宵亮 《吉林大学学报(地球科学版)》2021,51(2):624-637

三峡库区蓄水以来,长江周边出现了大量的水库地震,主要集中于巴东—泄滩—仙女山区域,目前已达上万次,最大震级为5.1级。通过野外地质调查及对已有水库地震数据进行研究,采用构造地质分析方法,对三峡库区仙女山和九畹溪断裂带水库地震空间上的迁移规律、时间上的周期规律以及微地震群的成因机理进行分析。结果表明：从时间上看,水库地震具有周期性,表现为长周期（与库水位相关）和短周期（与库水位快速波动相关）;从空间上看,水库地震具有迁移规律,受九畹溪断裂控制的触发型水库地震存在着逐渐向南迁移的特征,受仙女山断裂控制的触发型水库地震局限分布于仙女山断裂北延端点处,分布于仙女山断裂西侧（周坪乡附近）带状分布的水库诱发地震逐渐呈点状向南迁移。  相似文献   

Construction of soil–water characteristic curve of granular materials with toroidal model and artificially generated packings     

Bate  Bate  Nie  Shaokai  Chen  Zejian  Zhang  Fengshou  Chen  Yunmin 《Acta Geotechnica》2021,16(6):1949-1960

Acta Geotechnica - The soil–water characteristic curve (SWCC) of granular materials is crucial for many emerging engineering applications, such as permeable pavement and methane hydrate...  相似文献   

High-resolution uppermost mantle velocity structure beneath central Tibet and its implications for geodynamics     

Shitan Nie  Xiaobo Tian  Xiaofeng Liang  Yun Chen 《《地质学报》英文版》2018,92(Z1):55-55

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Elastic wave velocity monitoring as an emerging technique for rainfall-induced landslide prediction     

Yulong Chen  Muhammad Irfan  Taro Uchimura  Guanwen Cheng  Wen Nie 《Landslides》2018,15(6):1155-1172

Landslides are recurring phenomena causing damages to private property, public facilities, and human lives. The need for an affordable instrumentation that can be used to provide an early warning of slope instability to enable the evacuation of vulnerable people, and timely repair and maintenance of critical infrastructure is self-evident. A new emerging technique that correlates soil moisture changes and deformations in slope surface by means of elastic wave propagation in soil was developed. This approach quantifies elastic wave propagation as wave velocity. To verify its applicability, a series of fixed and varied slope model tests, as well as a large scale model test, were conducted. Analysis of the results has established that the elastic wave velocity continuously decreases in response of moisture content and deformation, and there was a distinct surge in the decrease rate of wave velocity with failure initiation, soil deformation was thus envisaged to have more significant effect on elastic wave velocity than water content. It is proposed that a warning be issued at switch of wave velocity decrease rate. Based on these observations, expected operation of the elastic wave velocity monitoring system for landslide prediction in the field application is presented. Consequently, we conclude that the elastic wave velocity monitoring technique has the potential to contribute to landslide prediction.  相似文献