【摘要】 岩石学结构和热结构表明大别碰撞造山带是由两个不同岩石—构造单元叠置形成,代表两个深部地壳物质剖面。本文通过对高压、超高压岩石形成过程中岩石物理(密度)性质分析,指出大陆长英质地壳自身在特定岩石学结构情况下可以俯冲至地幔深度。低温、快速折返是缺乏同碰撞和碰撞后花岗岩类的主要原因。“浮沉子效应”是超高压岩石形成和折返的力学机制。更多还原

【Abstract】 Both petrological structure and thermal structure indicate that the Dabie collislocks, representing two different deep crustal continental sections. From an analysis of the physical property (density) of the high-pressure (HP)-ultrahigh-pressure (UHP) metamorphic rocks, the authors suggest that the felsic crust can be subducted to the mantle depth if it has a special petrological structure. Both low temperature and rapid exhumation are believed to be the major reason for lack of both syncollisional and postcollisional granites. The float-sink effect is the mechanical mechanism for the formation and’exhumation of UHP rocks.更多还原