浙皖赣相邻区加里东期构造变形特征

Features of Caledonian tectonic deformation in the Zhejiang-Anhui-Jiangxi border region,China

浙皖赣相邻区在加里东时期受到华南加里东构造事件的影响,前震旦纪基底及早古生代早期盖层强烈隆升并褶皱变形,皖浙赣邻接部位早—中石炭世地层直接覆盖在中元古代浅变质岩系之上,东端清凉峰一带的中石炭统覆盖在上寒武统之上,但尚未见到有加里东期岩浆活动的证据。同时,古陆南侧及东侧震旦纪—早志留世盖层向南(东)滑脱,接触带附近与基底一并形成倒转产状及倒转褶皱;北侧向北滑脱形成滑覆褶皱及临溪盆地、兰田残留向斜盆地。印支、燕山事件对加里东构造形迹产生了不可忽略的改造,最终形成了基本延续至今的构造格局。

The Zhejiang-Anhui-Jiangxi border region was affected by the South China Caledonian tectonic event in the Caledonian period. As a result, the pre-Sinian basement and earliest Paleozoic cover were strongly uplifted and folded and the Early-Mid Carboniferous strata in the Zhejiang-Anhui-Jiangxi border region directly overlies the Mesoproterozoic low-grade metamorphic series and the Middle Carboniferous in the Qingliangfeng area at the eastern end of the region overlies the Upper Cambrian, but no evidence of Caledonian magmatism is found. In addition, the Sinian-Early Silurian covers on the southern and eastern sides of the craton are detached toward the two sides and overturned together with the basement near the contact zone to form overturned folds. The covers on the northern side are detached toward the north to form slip-superposed folds and the Linxi and Lantian relict synclinal basins. The Indosinian and Yanshanian events significantly modified the Caledonian tectonic features and finally formed the tectonic framework that in the main continues to the present.