摘要
采用接收函数反演方法，从INDEPTH-Ⅲ台站中选取了18个资料记录较好的台站，对拉萨及羌塘块体的地壳厚度与低速层的分布等进行了研究．结果表明，沿着INDEPTH-Ⅲ剖面，拉萨块体Moho界面较羌塘要深约8km，这可能暗示拉萨块体北缘的地幔盖层向北俯冲到羌塘块体之下；反演得到的地壳速度模型显示，拉萨北部及羌塘块体的部分台站下方中地壳有低速层存在，结合以往地质资料，可以推断拉萨块体北部和羌塘块体10～20km以下的中地壳普遍存在低速层．这些低速层可能与其下部的高温上地幔有直接关系．
To determine the crustal structure in central Tibet, we used teleseismic waveform data recorded by 18 stations in the INDEPTH-Ⅲ seismic array across the central Ti bet from the central Lhasa terrane to the central Qiangtang terrane. The S wave velocity structures beneath stations are determined by inverting the stacked radial receiver function using the GA method. The first order features in the receiver function are modeled. Our results show that the Moho in Qiangtang is about 8 km shallower than that in Lhasa terrane is along the INDEPTH-Ⅲ profile. It maybe suggests the northward subduction of the Lhasa mantle lid beneath the Qiangtang terrane is affected by the India-Asia collision. We conclude that there exist low velocity zone in the middle crust across the northern Lhasa and Qiangtang Terrane, which can be related to the high temperature upper mantle be neath that.
出处
《地震学报》
CSCD
北大核心
2006年第6期586-595,共10页
Acta Seismologica Sinica
基金
国家自然科学基金(40274029)
地震科学联合基金(105096)资助
关键词
青藏高原
接收函数
低速层
地壳厚度
Tibetan plateau
receiver function
low velocity zone
crustal thickness
作者简介
通讯作者．E-mail：lyhgeomag@sina．com.
