冀京津地区燕山构造旋回岩石圈演化探讨

A discussion on lithosphere evolution of Yanshan tectonic cycle in Hebei-Beijing-Tianjin region

冀京津地区燕山构造旋回岩石圈的演化构成一个完整的构造演化旋回,岩石圈经历了晚三叠世早期拉张裂解(非造山)、晚三叠世晚期稳定过渡(前造山)、早侏罗世至早白垩世中期挤压板内造山(同造山)、早白垩世晚期至古新世稳定过渡(后造山)的发展演化阶段。在燕山构造旋回板内造山过程中,原有克拉通型岩石圈被强烈改造与再造,形成新的造山型岩石圈,这是燕山构造旋回最为重要的内容和板内造山的实质性结果。

The lithospheric evolution of Hebei- Beijing- Tianjin region constitutes a complete tectonic evolution cycle. The lithosphere experienced multi- stage evolution, comprising tension cracking(non- orogenic) at the early stage of Late Triassic,stable transition at the late stage of Late Triassic(pre-orogenic), squeeze intraplate orogeny between the Early Jurassic and middle stage of Early Cretaceous(sym- orogenic), and stable transition during Cretaceous- Paleocene(post- orogenic). During the intraplate orogenic process of Yanshan tectonic cycle, the original cratonic lithosphere was strongly transformed and rebuilt, and formed a new orogenic lithosphere, which seems to have been the most important content of the Yanshan tectonic cycle and the substantive result of intraplate orogeny.