| 残余壳根与"三明治"结构——燕山造山带中段地壳结构的主要特征 |
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| 关键词:Yanshan orogen deep seismic sounding (DSS) profile crustal structure remainder crustal root |
| 基金项目:中国地质大调查项目(编号:200213000040); 国家自然科学基金项目(编号:40334035) |
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| Remainder Crustal Root and Decoupling-Main Characteristics of Crust Structure beneath the Yanshan Intracontinent Orogen |
| The Changli-Chengde-Dalainuoer wide-angle/refraction seismic profile completed in 1985 extends northwestward across the Yanshan orogen. It is partly overlapped by a reflection seismic profile completed in 2002. For the purpose of understanding the regional deep tectonic setting and on the basis of interactive interpretation between the near-vertical reflection profile and the wide-angle reflection profile, this paper dealt with four shot data from the profile. As a result, a sandwich style crust structure model of the remainder crustal root 35～38 km in thickness intercalated with an intracrust lower velocity layer was obtained. This pattern is evidently different from the diagram of wedge /insert that often appears under the interplate underthrust or collision orogen, and is also different from the 'thick-skinned' pattern under the Alice Spring orogen of Australia, thus having its distinct features in the intra-continent orogenic belts of the world. The crustal structure suggests that the framework formed by Mesozoic regional contraction deformation was preserved in the Yanshan orogen. Nevertheless, characteristics of the lower crust and Moho indicate the existence of the influence of late regional stretching. |
| LI Qiu-sheng,GAO Rui,ZHANG Cheng-ke,ZHAO Jin-ren,GUAN Hua,ZHANG Ji-sheng.2008.Remainder Crustal Root and Decoupling-Main Characteristics of Crust Structure beneath the Yanshan Intracontinent Orogen[J].Acta Geoscientica Sinica,29(2):129-136. |
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