复杂地壳接收函数H-κ叠加——以安纳托利亚板块为例

发布时间：2018-04-23 19:22

本文选题：接收函数H-κ叠加 + 波形反演　；参考：《地球物理学报》2016年11期

【摘要】：本文理论分析了具有不同沉积层和壳幔过渡带结构的接收函数及其相关的H-κ叠加结果,然后采用接收函数H-κ叠加和波形反演方法获得了具有复杂构造演化历史的中北安纳托利亚板块的地壳厚度(H)、V_P/V_S(κ)和V_S结构.理论分析表明:厚的沉积层或沉积层和厚的壳幔过渡带共存都会使H-κ叠加失效;渐变型壳幔过渡带导致H-κ叠加的H位于过渡带中间,且随着频率增大逐渐靠近过渡带上方;倒转型壳幔过渡带导致H-κ叠加具有多极值,其结果可能反应过渡带内最大波阻抗界面上的地壳结构;1km·s~(-1)的V_P变化会导致H-κ叠加的H变化7km,而κ变化较小.实际资料分析表明:中北安纳托利亚H,κ和V_S具有强烈的横向不均匀性,大部分区域沉积层厚度0.5km,局部地区壳幔过渡带厚度3km;北安纳托利亚断层切穿地壳,在局部地区可能存在流体;研究区存在残留古老的小陆块体.本文研究表明,仔细分析接收函数波形和其随方位角的变化特征且用其他地震学方法进行约束,有助于采用H-κ叠加方法获取复杂地壳结构信息.
[Abstract]:In this paper, the reception function with different sedimentary layers and crust-mantle transition zone structures and its related H- 魏 superposition results are theoretically analyzed. Then the crustal thickness of the central and northern Anatolian plate with complex tectonic evolution history is obtained by using the reception function H- 魏 stack and waveform inversion method. The theoretical analysis shows that the coexistence of thick sedimentary layer or sedimentary layer and thick crust-mantle transition zone will invalidate H- 魏 superposition, and the H of H- 魏 superimposed transition zone is located in the middle of the transitional zone with the increase of frequency, and gradually approaches to the top of the transitional zone with the increase of frequency. The transition zone of crust and mantle leads to the multi-extreme value of H- 魏 superposition. The results may reflect the VSP variation of the crustal structure at the maximum wave impedance interface of 1 km / s ~ (-1) in the transition zone, which will lead to the change of H- 魏 superposition H by 7km, but the change of 魏 is relatively small. The analysis of the actual data shows that there are strong transverse inhomogeneity in the central and northern Anatolia (H, 魏 and V\ + + S), the thickness of the sedimentary layer in most areas is 0.5 km, the thickness of the crust and mantle transition zone in some areas is 3 km, the thickness of the North Anatolian fault is cut through the crust, There may be fluids in local areas, and there are ancient residual small landmasses in the study area. In this paper, it is shown that careful analysis of receiving function waveform and its variation with azimuth and constraint by other seismological methods are helpful to obtain complex crustal structure information by H- 魏 superposition method.
【作者单位】：中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室;中国科学院地质与地球物理研究所岩石圈演化国家重点实验室;中国科学院青藏高原地球科学卓越创新中心;
【基金】：国家重点基础研究发展计划项目(2013CB733203) 国家自然科学基金项目(41225016,41604056) 大地测量与地球动力学国家重点实验室自主课题(Y509169216)资助
【分类号】：P315.2

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