海南岛地壳厚度与泊松比结构.pdf

热带海洋学报 JOURNAI. OF TROPICAI. OCEANOGRAPHY
2012年第31卷第3期:65-70
海洋地球物理学doi10.3969jis1004702012,03,00
http:/www.jto.ac.cn
海南岛地壳厚度与泊松比结构
黄海波2,丘学林1,夏少红1
1.中国科学院边缘海地质重点实验室,中国科学院南海海洋研究所,广东广州510301:
2.中国科学院研究生院,北京100039
摘要:地売厚度和泊松比是了解地球内部介质的重要参数,研究二者之间的关系能够为揭示深部地壳结构特征提
供重要信息。本文提取了海南岛固定地震台站记录到的远震接收函数波形,通过在地売厚度和波速比域对売一幔
间断面的Ps转换波及其多次波震相进行振幅叠加,同时参考人工地震探测结果,获得了海南岛地区的地壳厚度和
泊松比分布。结果显示:海南岛地区地売厚度为26-31lm;受普遍发育的花岗岩以及火山作用影响、其泊松比值
基本小于0.26,地売厚度与泊松比之间存在正消长关系,表明该区的构造伸展作用主要造成富含镁铁成分的下地
売的明显減薄;部分地区的上地売可能存在褶皱或逆冲推覆构造,其泊松比出现低值异常。
关键词:海南岛;接收函数;H-k叠加;地壳厚度;泊松比
中图分类号:P738.4文献标识码:A文章编号:1009-5470(2012)03-(065-06
Crustal structure and Poisson's ratio beneath Hainan Island
HUANG Hai-bo "", QIU Xue-lin, XIA Shao-hon
CS Key laboratory of Marginal ea (eology, South China Sea Institute f ceanolog The Chinese Academy of ciences
Guangzhou 510301, China
2. Graduate School of the Chineseacademy of Sciences, Beijing 100039, China
Abstract: Crustal thickness (H)and Poisson's ratio ()are iwo imporlant parameters to understand the interior of the Farth
Correlation between the two can reveal important information of the character of the crustal structure. Teleseismic receiver
functions recorded by the permancnt scismic stations distributed around Ilainan Island are extracted to scarch the Ps converted
wave and its multiples from discontinuities in the crust and mantle, and some artificial earthquake probing results are taken for
references to determine the average thickness and the Poissons ratio beneath Hainan Island Tthe results show that the crust
thickness of Hainan is 26-31 km and the Poisson,s ratio is lower than 0.26 beneath the island for the widespread granite and
volcano activities. T his area seems to display a positive correlation between H and v, which indicates that the tectonic
extcnsion function is mainly caused the obvious reduction of lower crustal thickness; Poisson,s ratios in some yones are
extremely low, possibly due to fold-thrust belts of the upper crus
ey words: Hainan Island: receiver function: H-kstacking: crustal thickness: Poissons ratio
海南岛位于欧亚板块、印度一澳大利亚板块和多期扩张活动影响,海南岛地区地质构造比较复杂,
菲律宾板块的交汇处,其大地构造位置独特,是理不仅发育了丰富的断裂构造,而且普遍存在火山活
解亚洲东南部大陆增生、陆缘演化以及南海形成的动,是研究海陆形成与演化以及深部物质运动的重
关键地区叫!受板块相互作用,特别是受南海海盆的要地区。
收稿日期:2011-10-14;修订日期:2012-02-20。卢冰编辑;林强校对
基金项目:国家自然科学基金项目(41074066:41006028);广东省自然科学基金项目(1(0451030101004522);国家重点基础研究发展计划
项目(2007CB411701)
作者简介:黄海波(1985-)男,安徽省淮南市人。助理研究员,博士,主要从事海洋地球物理研究。E-mai:go223 auscs.ac.cn