CAJ | 학술논문

本文通过对马尔康-古浪宽角反射和折射剖面高精度观测段(200～400 km)的Pg、Sg资料的分析解释,给出了该区段上地壳速度结构和泊松比分布.并利用震相识别误差分析、分辨率计算及不同初始模型筛选等方法,使走时反演结果的可靠性进一步提高.研究表明:对应于阿尼玛卿缝合带的275km～355 km桩号段内平均泊松比高达0.297,P渡和S波速度呈横向高低速条带变化,库赛湖-玛沁断裂和舟曲-两当断裂基本上均位于高泊松比和低速带内,并分别处在缝合带与若尔盖盆地和西秦岭褶皱带的分界上.阿尼玛卿缝合带南侧的若尔盖盆地平均泊松比较低,约为0.257,北侧西秦岭褶皱带的平均泊松比为0.264.
본문통과대마이강-고랑관각반사화절사부면고정도관측단(200～400 km)적Pg、Sg자료적분석해석,급출료해구단상지각속도결구화박송비분포.병이용진상식별오차분석、분변솔계산급불동초시모형사선등방법,사주시반연결과적가고성진일보제고.연구표명:대응우아니마경봉합대적275km～355 km장호단내평균박송비고체0.297,P도화S파속도정횡향고저속조대변화,고새호-마심단렬화주곡-량당단렬기본상균위우고박송비화저속대내,병분별처재봉합대여약이개분지화서진령습추대적분계상.아니마경봉합대남측적약이개분지평균박송비교저,약위0.257,북측서진령습추대적평균박송비위0.264.
We obtained velocity structure and Poisson's ratio distribution in the upper crust by the high resolution refraction section (200 ～ 400km) which belongs to Maerkang - Gulang wide-angle reflection and refraction profile inversed from Pg and Sg data. Reliability of inversed model is improved using the phases identification error analysis, resolution calculation and choice of different initial models. The results reveal that the average Poisson' s ratio between 275～355km is as high as 0.279 and P-wave velocity and S-wave velocity are banded laterally beneath the A'ny(e)maq(e)n suture zone. The Kusaihu- Maqin fault and Zhouqu-Liandang fault are in zones of high Poisson's ratio and low velocity and the faults are boundaries of the Roergai basin and Qinling fold zone, respectively. The average Poisson's ratio of the Roergai basin which is on the south side of the A'ny(e)maq(e)n suture zone is 0. 257 and the average Poisson's ratio of the West Qinling fold zone which is on the north side of the Animaqin suture zone is 0.264.