川东北宣汉盘龙洞长兴组生物礁剖面沉积相分析     

邱小松  胡明毅  胡忠贵  赵恩璋 《海洋地质译丛》2011,(3):39-44

结合区域构造、地层概况、岩相古地理等方面的背景资料,对宣汉盘龙洞上二叠统长兴组生物礁地层剖面进行了观测描述。通过室内镜下岩石薄片鉴定分析,识别出主要岩石类型为礁灰岩、礁云岩、生屑灰岩、颗粒灰岩及晶粒白云岩。根据露头观察和室内镜下岩石薄片鉴定分析,结合岩石学、古生物等沉积相标志的研究,认为该剖面发育开阔台地、台地边缘生物礁和台地边缘浅滩三种沉积相类型,其中台地边缘生物礁发育,可进一步识别出礁基、礁核和礁前亚相,礁核以骨架礁和障积礁为主;台地边缘浅滩进一步划分为粒屑滩、鲕粒滩等亚相。初步总结出了该剖面的沉积相模式,并对该剖面的沉积演化序列和识别标志进行了讨论。  相似文献   

山西数字化水管倾斜仪观测资料质量分析     

冯建琴  沈晓松  董甲弟  程东焱  高振强  高跃雄  邓建梅  田文清 《地震地磁观测与研究》2011,32(3):100-108

对山西省代县、太原、侯马地震台数字化水管倾斜仪2008年1月-2010年10月的观测资料作质量评定,阐述其台址条件,找出水管倾斜仪的日变规律,精确计算各台站连续率、完整率、内精度、噪声水平、年零漂、年变幅;对影响观测质量精度、观测资料的主要因素进行分析,排除干扰,识别地震异常,为今后提升各台站观测资料质量,提供参考.  相似文献   

Using large dynamite shots to image the structure of the Moho from deep seismic reflection experiment between the Sichuan basin and Qinling orogen          下载免费PDF全文

Hongqiang Li  Rui Gao  Haiyan Wang  Wenhui Li  Xiaosong Xiong 《地震科学（英文版）》2016,29(6):321-326

The Qinling orogen was formed as a result of the collision between the North and South China blocks. The Qinling orogen represents the location at which the southern and northern parts of the Chinese mainland collided, and it's also the intersection of the Central China orogen and the north-south tectonic belt. There is evidence of strong deformation in this orogen, and it has had a long and complex geological history. We investigated the structure of the Moho in the southern Qinling orogen using large dynamite shot imaging techniques. By integrating the analysis of the single-shot and the move-out corrections profile, we determined the structure of the Moho beneath the northern Dabashan thrust belt and the southern Qinling orogen, including the mantle suture beneath Fenghuang mountain. The Moho is divided into two parts by the mantle suture zone beneath Fenghuang mountain:(1) from Ziyang to Hanyin, the north-dipping Moho is at about45–55 km depth and the depth increases rapidly; and(2)from Hanyin to Ningshan, the south-dipping Moho is at about 40–45 km depth and shallows slowly. The mantle suture is located beneath Fenghuang mountain, and the Moho overlaps at this location: the shallower Moho is connected to the northern part of China, and the deeper Moho is connected to the southern part. This may indicate that the lithosphere in the Sichuan basin subducts to the Qinling block and that the subduction frontier reaches at least as far as Fenghuang mountain.  相似文献   

Frozen subduction in the Yangtze block: insights from the deep seismic profiling and gravity anomaly in east Sichuan fold belt          下载免费PDF全文

Xiaosong Xiong  Rui Gao  Haiyan Wang  Jisheng Zhang  Lianghui Guo 《地震科学（英文版）》2016,29(2):61-70

The Sichuan basin is the main part of the middle-upper Yangtze block, which has been experienced a long-term tectonic evolution since Archean. The Yangtze block was regarded as a stable block until the collision with the Cathaysia block in late Neoproterozoic. A new deep seismic reflection profile conducted in the eastern Sichuan fold belt (ESFB) discovered a serials of south-dipping reflectors shown from lower crust to the mantle imply a frozen subduction zone within the Yangtze block. In order to prove the speculation, we also obtain the middle-lower crustal gravity anomalies by removing the gravity anomalies induced by the sedimentary rocks and the mantle beneath the Moho, which shows the mid-lower crustal structure of the Sichuan basin can be divided into eastern and western parts. Combined with the geochronology and Aeromagnetic anomalies, we speculated the Yangtze block was amalgamated by the West Sichuan and East Sichuan blocks separated by the Huayin-Chongqing line. The frozen subduction zone subsequently shifted to a shear zone accommodated the lower crustal shortening when the decollement at the base of the Nanhua system functioned in the upper plate.  相似文献   

CINRAD/CD型雷达伺服系统故障分析及处理     

周枫  倪雷  刘朝林  罗晓松  李明元 《气象科技》2009,37(4):508-510

1故障情况简述 （1）毕节雷达故障。 ①2007年3～4月期间,反复出现雷达天线不能正常完成体扫,但清洗汇流环、调整伺服放大器后故障消除的现象。  相似文献   

Moho Depth of Qinghai-Tibet Plateau Revealed by Seismic Probing     

Xiong Xiaosong  Gao Rui  Li Qiusheng  Lu Zhanwu 《中国地质大学学报(英文版)》2009,20(2)

The Qinghai (青海)-Tibet plateau is the newest and biggest orogenic belt in the world and a natural laboratory for researching continental geodynamics, such as continent-continent collision, convergence, subduction, and plateau uplift. From the 1950s to the present, there have been many active-source (deep seismic sounding and deep seismic reflection profiling) and passive-source seismic probing (broadband seismic observations) implemented to reveal the crust-mantle structure. In this article, the authors mainly summarize the three seismic probings to discuss the Moho depth of the Qinghai-Tibet plateau based on the previous summaries. The result shows that the Moho of the Qinghai-Tibet plateau is very complex and its depth is very different; the whole outline of it is that the Moho depth is deeper beneath the south than the north and deeper in the west than in the east. In the Qiangtang (羌塘) terrane, the hinterland of the Qinghai-Tibet plateau, the Moho is shallower than both the southern and the northern sides. The deepest Moho is 40 km deeper than the shallowest Moho. This trend records the crustal thickening and thinning caused by the mutual response between the India plate and the Eurasia plate, and the eastward mass flow in the Qinghai-Tibet plateau.  相似文献   

北京西山岩溶水系统渗透系数计算及富水性分析     

刘崇军  刘全国  于洋  王小松 《城市地质》2017,12(2)

在北京西山岩溶水系统243个简易抽水试验的基础上,分析了岩溶含水层的出水能力,应用稳定流和非稳定流方法计算了含水层的渗透系数。通过对比分析,确定了北京西山地区岩溶水系统富水区域为房山拒马河流域十渡—马安泉及张坊地区、大石窝镇半壁店村附近和甘池泉附近的蓟县系雾迷山组含水岩组,房山大石河流域河北镇、房山岩体南侧篓子水村附近、西山山前三厂水源地及海淀山后温泉镇地区的寒武奥陶系含水岩组。本次工作弥补了西山地区岩溶水水文地质参数的空白与偏差,为岩溶水资源评价和开发利用提供了数据支撑。  相似文献   

楚雄前陆盆地的构造特征与沉积演化   总被引：13，自引：6，他引：7  

谭富文  尹福光  许效松  陈明 《大地构造与成矿学》2004,28(3):345-352

对楚雄前陆盆地西部及相邻构造格架进行了分析 ,认为原形盆地的西南部及相邻造山带受到了新生代红河断裂的强烈改造 ,而盆地西北部的盆 -山体系保留了盆地演化时期的基本格架。利用当代前陆盆地演化模式理论 ,对原形盆地的沉积特征及其与西部推覆构造的耦合关系进行了综合分析 ,认为扬子西部被动陆缘向楚雄前陆盆地转化的时期发生在晚三叠世卡尼早期 ,前陆盆地经历了 3个发展阶段 :卡尼期深水复理石沉积、诺利期浅水复理石沉积和瑞替期磨拉石沉积 ,并提出了相应的沉积 -构造演化模式。  相似文献   

中国南方早古生代碳酸盐台地形成与发展   总被引：1，自引：0，他引：1       下载免费PDF全文

徐强  刘宝珺  许效松 《沉积与特提斯地质》1996,16(4):1-5

中国南方碳酸盐台地从震旦纪到志留纪十分发育，它对认识中国南方沉积地壳演化和油气勘探具有重要意义。９０年代以来，中国南方碳酸盐台地从台地内部结构研究发展到对碳酸盐台地边缘、台地几何形态、台地边缘形态的研究，并把它们的形成和演化与大地构造、全球海平面变化、沉积层序、动力演化过程结合起来，进行碳酸盐台地发展、演化、沉降、生长的定量模拟、此外，还特别重视重大地质事件和非现实主义沉积作用探索。中国南方早古生代碳酸盐台地，随着扬子板块的裂谷拉张、被动大陆边缘构造热沉降和前陆挠曲，经历了碳酸盐台地产生、发展和消亡的完整威尔逊旋回动力演化、最终这个巨大的碳酸盐台地因挠曲沉降淹没和大量碎屑岩覆盖而消亡，是具有非常良好远景的油气资源探区。  相似文献   

西藏亚东淡色花岗岩Rb—Sr和Sm—Nd同位素研究——关于其年龄和源岩的证据   总被引：16，自引：1，他引：16       下载免费PDF全文

杨晓松  金振民 《地质论评》2001,47(3):294-300

对西藏亚东淡色花岗岩Rb-Sr和Sm-Nd同位素的详细研究表明,亚东淡色花岗岩Rb-Sr和Sm-Nd同位素组成十分不均匀,其初始Sr值和ε-(Nd)(13 Ma)分别介于0.756～0.775和-11.6～-16.3。由于存在着显著的同位素变异,而难以获得其全岩Rb-Sr等时线年龄。但研究获得了12.9±0.95Ma矿物—全岩Rb-Sr等时线年龄,其锶初始值为0.7744±0.0008,该年龄可以与高喜马拉雅带其他淡色花岗岩的年龄对比。Rb-Sr和Sm-Nd同位素组成显示亚东淡色花岗岩的源岩很可能是聂拉木群副变质岩。年龄统计分析表明,喜马拉雅淡色花岗岩是在地壳伸展和快速隆起背景下形成的,因此它的形成年龄是碰撞造山后地壳强烈活动和快速隆起的重要标志。  相似文献