干旱区生态环境知识资源中心(Arid): 南沙西南部下地壳高速层成因

Arid

	南沙西南部下地壳高速层成因
其他题名	Origin of High Velocity Layer in Lower Crust of Southwestern Nansha Block
	李凯 1; 沈传波 1; 谢晓军 2; 赵志刚 2; 彭希 1; 周延冰 1
来源期刊	地球科学
ISSN	1000-2383
出版年	2019
卷号	44 期号:3 页码:810-821
中文摘要	高速层成因的争议限制了对南海深部结构、构造演化以及南海完整演化历史的认识.运用Oasis Montaj软件对穿越南沙西南部的最新地震测线进行重震联合反演,分析莫霍面起伏、地壳厚度及高速层的分布,计算全壳伸展因子和现今高速层的温度、识别火山时代,并探讨高速层的成因.南薇西盆地和礼乐盆地区伸展因子为1.5~4.0,未达到蛇纹石发育条件;南沙海槽区伸展因子大,最大为11.2,海水可通过深大断裂下渗与橄榄岩反应生成蛇纹石,高速层处温度低于蛇纹石稳定温度;通过地震剖面确定火山在南海停止扩张之后形成.研究结果表明,南沙西南部高速层按成因分为两类,南薇西盆地和礼乐盆地区为南海扩张停止后火山喷发残余的岩浆,而南沙海槽盆地区为早期橄榄岩的蛇纹石化与南海停止扩张后岩浆的混合体.
英文摘要	The controversy over the genesis of the high velocity layer limits the understanding of the deep structure,tectonic evolution and complete evolution of the South China Sea.In order to understand the origin of high velocity layer in the lower crust of the southwestern Nansha block,the joint inversion of gravity and seismic data was performed by using Oasis Montaj software in this study.The seismic profile is across the southwestern Nansha Block.The Moho undulation,crustal thickness and the distribution of the high velocity layer are recorded.The regional extension factor and the temperature at the high layer depth are calculated,and the age of volcanic eruption is determined by seismic features.The whole crustal stretching factor of the Nanweixi Basin and the Liyue Basin area is 1.5-4.0,which is impossible to develop serpentine.The whole crustal stretching factor is up to 11.2in the Nansha trough.The serpentine is formed by the reaction of peridotite and sea water which enters the mantle through the fractures.The temperature near the high velocity layer is lower than the stable temperature of the serpentine.The volcanic eruption was found in the same place in the seismic profile,and the volcano formed after the cessation of the spreading of the South China Sea.The results indicate that the high velocity layer of the southwestern Nansha Block can be divided into two types.The high velocity layer in the Nanweixi and the Liyue basins is formed by volcanic eruption after the cessation of the spreading of the South China Sea;and the other section in the Nansha trough basin is a mixture of serpentinized peridotite and late magma.
中文关键词	南沙 ; 深部结构 ; 高速层 ; 火山 ; 伸展因子 ; 蛇纹石化 ; 海洋地质
英文关键词	Nansha deep crustal structure high velocity layer volcano stretch factor serpentinization marine geology
语种	中文
国家	中国
收录类别	CSCD
WOS类目	MINERALOGY
WOS研究方向	Mineralogy
CSCD记录号	CSCD:6474054
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/239009
作者单位	1.(武汉)中国地质大学;;(武汉)中国地质大学资源学院, 构造与油气资源教育部重点实验室;;, 武汉;;武汉, 湖北;;湖北 430074;;430074, 中国; 2.中海油研究总院有限责任公司, 北京 100028, 中国
推荐引用方式 GB/T 7714	李凯,沈传波,谢晓军,等. 南沙西南部下地壳高速层成因[J],2019,44(3):810-821.
APA	李凯,沈传波,谢晓军,赵志刚,彭希,&周延冰.(2019).南沙西南部下地壳高速层成因.地球科学,44(3),810-821.
MLA	李凯,et al."南沙西南部下地壳高速层成因".地球科学 44.3(2019):810-821.