熊盛青^1,2,,
周道卿^1,2,,,
曹宝宝¹,
赵睿¹,
魏岩岩¹,
胡悦¹,
肖梦楚¹,
段宏伟¹,
胡夏炜¹,
郑宇舟¹
1. 中国自然资源航空物探遥感中心, 北京 100083
2. 自然资源部航空地球物理与遥感地质重点实验室, 北京 100083

基金项目: 中国地质调查局"羌塘及塔里木等盆地航空物探调查"项目（DD20160065），"银额盆地及外围航空物探调查"项目（D20190025）联合资助


详细信息

作者简介: 熊盛青, 男, 博士生导师, 教授级高级工程师, 长期从事航空地球物理、遥感技术及其地学应用研究工作.E-mail:xsq@agrs.cn

通讯作者: 周道卿, 男, 博士后, 教授级高级工程师, 长期从事航空地球物理调查与盆地构造研究工作.E-mail:zhoudqchina@163.com

中图分类号: P631

收稿日期:2020-05-09
修回日期:2020-07-21
上线日期:2020-09-05

Characteristics of the central uplift zone in Qiangtang Basin and its tectonic implications: Evidences from airborne gravity and magnetic data

XIONG ShengQing^1,2,,
ZHOU DaoQing^1,2,,,
CAO BaoBao¹,
ZHAO Rui¹,
WEI YanYan¹,
HU Yue¹,
XIAO MengChu¹,
DUAN HongWei¹,
HU XiaWei¹,
ZHENG YuZhou¹
1. China Aero Geophysical Survey and Remote Sensing Center for Natural Resources, Beijing 100083, China
2. Key Laboratory of Airborne Geophysics and Remote Sensing Geology, Ministry of Natural Resources, Beijing 100083, China


More Information

Corresponding author: ZHOU DaoQing,E-mail:zhoudqchina@163.com

MSC: P631

--> Received Date: 09 May 2020
Revised Date: 21 July 2020
Available Online: 05 September 2020


摘要
摘要:对于羌塘盆地是否存在横贯东西的中央隆起带，目前学术界仍有分歧.本文提供的最新高精度航空重、磁资料证实存在呈东西向贯通羌塘盆地的中央隆起带，并对该带的构造特征进行了精细刻画.隆起带受南北两侧深大断裂控制，其空间跨度（宽度）由西向东逐渐收敛，并被一组近南北向的隐伏断裂系切割、左滑错动.重、磁场资料还显示中央隆起带在双湖东、西两侧存在明显差异：西段基底大规模隆起，基岩深度一般在3~5 km以内，明显浅于南北羌塘坳陷7~15 km的基底埋深；东段基底隆起幅度明显降低，主要表现为潜伏的低隆起，其中双湖—雅曲段基底埋深5~7 km，雅曲—岗尼段基底埋深7~9 km；即中央隆起带基底自西向东"台阶状"降低，隆起的幅度和分布范围受到近南北向断裂控制.构造分层表明，与南羌塘地块相比，北羌塘地块的基底隆起幅度小、稳定性更好.南北羌塘基底地球物理属性的显著差异说明羌塘盆地并不存在统一的前寒武系变质基底，中央隆起带的形成应该与古特提斯洋关闭时形成的混杂岩带有关.
关键词: 羌塘盆地/
中央隆起带/
航空重磁/
基底深度/
构造分层/
地质意义

Abstract:Academia still has different opinions on whether there is a consecutive central uplift belt in the Qiangtang Basin. The latest high-precision airborne gravity and aeromagnetic data provided in this article verify the existence of the central uplift belt, which is controlled by two faults, traversing the Qiangtang Basin from east to west. A set of near-north-south left-lateral slip fault systems divide this uplift belt into several parts. The uplift belt, gradually converged from west to east, has obviously different characteristics between the east and west sides of Shuanghu County. The west section shows large-scale uplift of the basement, and the bedrock depth is generally within 3~5 km, which is much shallower than those in the North and South Qiangtang depression with the basement depth of 7~15 km. However, the uplift amplitude of the eastern segment decreases significantly, mainly manifested as a low base uplift. In addition, the central uplift belt shows obvious "multi-segments" and "step-like" decreasing trend from west to east, controlled by near-north-south faults. The basement depth of the Shuanghu-Yaqu section is between 5 and 7 km, and that of the Yaqu-Gonney section is between 7 and 9km. According to the structural stratification comparison, it is reveraled that the North Qiangtang Block has a smaller uplift amplitude and better stability than the South Qiangtang Block. The differences in geophysical properties of the basement between the North and South Qiangtang depression indicate that there is not an unified Precambrian metamorphic basement in the Qiangtang Basin, and the formation of the central uplift zone may be related to the melange zone formed during the closure of the Paleo-Tethys Ocean.
Key words:Qiangtang Basin/
Central uplift zone/
Airborne gravity and magnetic data/
Basement depth/
Structural stratification/
Geological implications



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