Structural Characteristics of the Basement beneath Qiangtang Basin in Qinghai-Tibet Plateau: Results

来源 :Acta Geologica Sinica(English Edition) | 被引量 : 0次 | 上传用户:ytcjy
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The studies on configuration, character/property of the basement of Qiangtang basin is helpful for evaluating petroleum and nature gas resources as well as understanding the basin evolvement. Recently a moderate to high-grade metamorphic gneiss rock was found underlying beneath very low metamorphic Ordovician strata in Mayer Kangri to the north of the central uplift. That fact actually proved existence of the crystalline basement just the distribution and structures of pre-Paleozoic crystalline basement still remain puzzle. In recent years a number of active sources deep seismic profiling, to aim at lithospheric structure of northern Tibet and petroleum resources of the Qiangtang basin, had been conducted that make it possible to image the structure of the basement of the Qiangtang. Near vertical reflection profiles, included those acquired previously and those during 2004 to 2008, have been utilized in this study. By through the interaction process and interpretation between the reflection profiles and the wide-angle profile, a model with the detailed structure and velocity distribution from surface to the depth of 20 km of Qiangtang basin has been imaged.Based on the results and discussions of this study, the preliminary conclusions are as follows: (1) The velocity structure section (~20 km) that is interactively constrained by the refraction and reflection seismic data reveals that the sedimentary stratum gently lie until 10 km in the south Qiangtang basin. (2) The basement consists of fold basement (the upper) and crystalline basement (the lower).The fold basement buried at the average depth of 6 km with a velocity of 5.2-5.8 km/s. The shallowest appear at range of the central uplift. The crystalline basement is underlying beneath the fold basement at the average depth of 10 km with a velocity of 5.9-6.0 km/s except near Bangong-Nujiang suture. (3) The high-velocity body at the depth range of 3-6 km of the central uplift is considered as a fragment of the crystalline basement that perhaps was raised by Thermal or deformation. (4) The lower-consolidated fold basement show more affinity of Yangtze block but the crystalline basement seems more approximate to Lhasa terrene in geophysical nature. We have attempted to improve the resolution and reliability by interaction of the active seismic data and prove it effective to image complex basement structure. It will be a potential to process the piggy-back acquisition data and has wide prospects. The studies on configuration, character / property of the basement of characterization of the basement of Qiangtang basin is helpful for evaluating petroleum and nature gas resources as well as understanding the basin evolvement. Recently a moderate to high-grade metamorphic gneiss rock was found under beneath very low metamorphic Ordovician strata in Mayer Kangri to the north of the central uplift. That fact actually proven of the crystalline basement just the distribution and structures of pre-Paleozoic crystalline basement still remain puzzle. In recent years a number of active sources deep seismic profiling, to aim at lithospheric structure of northern Tibet and petroleum resources of the Qiangtang basin, had been conducted that make it possible to image the structure of the basement of the Qiangtang. Near vertical reflection profiles, included those previously acquired and that during 2004 to 2008, have been utilized in this study. By through the interaction process and interpretation between the refle ction profiles and the wide-angle profile, a model with the detailed structure and velocity distribution from surface to the depth of 20 km of Qiangtang basin has been imaged. Based on the results and discussions of this study, the preliminary conclusions are as follows: (1) The velocity structure section (~ 20 km) that is interactively constrained by the refraction and reflection seismic data reveals that the sedimentary stratum gently lie until 10 km in the south Qiangtang basin. (2) The basement consists of a fold basement (the The shallow base appear buried in the average depth of 6 km with a velocity of 5.2-5.8 km / s. The shallow base appear in the range of the central uplift. The crystalline basement is the underlying beneath the fold basement at the average depth of 10 km with a velocity of 5.9-6.0 km / s except near Bangong-Nujiang suture. (3) The high-velocity body at the depth range of 3-6 km of the central uplift is considered as a fragment of the crys talline basement that perhaps was raised by Thermal or deformation. (4) The lower-consolidated fold basement show more affinity of Yangtze block but the crystalline basement seems more approximate to Lhasa terrene in geophysical nature. We have attempted to improve the resolution and reliability by interaction of the active seismic data and prove it effective to image complex basement structure. It will be a potential to process the piggy-back acquisition data and has wide prospects.
其他文献
拿破仑的著名说法是,“让中国熟睡吧,因为一旦她醒来,她将震惊世界。”拿破仑走在他的时代的前面,但如今中国龙无疑正在觉醒。自邓小平最初使他的国家走上经济改革道路的1978
现代公路建设施工质量管理的内涵比过去更为丰富,它不仅受到思想、技术、组织、经济等方面的制约,本文探索了适合我国国情和现时特点的施工质量管理方式和质量保证体系。 Th
《非洲猎豹》科学家大卫和克瑞斯泰在非洲猎豹经常出没的森林里搭起了棚子,进行非洲猎豹的研究,他们依循猎豹的足迹拍摄影片,以便研究猎豹的起居饮食等生活习惯。一天夜里,
一应用语言学以解决语言与社会、语言与科技等的实际应用为主要研究对象。它作为一门独立的学科在本世纪中叶诞生以来,已经取得长足的进展,在语言应用、语言习得、语言教学、
前言:本刊从1982年第一期起开辟日语会话讲座。准备用一年左右的时间陆续登载日语常用会话300句(不包括回答句及方括号内或用“○”表示的类似句)并加以简单的说明及用法。
世界贫困人口的近2/3分布在亚洲,社会救助作为最后的安全网和反贫困的有效手段可以扩大社会保障的覆盖面并为这些贫困人口提供适当的社会保护。目前,亚洲各国的社会救助不够
东京一家出版社1981年出版了一种别致的“日历”——说得准确一点,是三天翻一张的“三日历”。据说,它是专门为那些懒得每天翻日历的人准备的。它出版后销路颇佳,很快就销售
分析了钢渣的使用性能,通过试验与实践证明钢渣的使用可大大降低工程造价。 The performance of steel slag was analyzed. The use of steel slag proved that the project
目的分析新疆阿勒泰地区艾滋病的流行状况,为今后的防治措施提供科学依据。方法利用艾滋病疫情直报系统中的数据,分析2006—2013年阿勒泰地区艾滋病疫情状况。结果 2006年1月
故事中的机密消息: 关于此人:奥斯仃威力,在白天他是一个摄影师,在夜晚他是一个国际级的神秘之人; 关于毛九(MOJO):是奥斯仃威力的力量源泉,是躲在他性欲之后的神奇所在,但