大别山太湖-马庙断裂带两侧变质地体的增温变质作用

Temperature increase metamorphism along the south boundary of the Dabie eclogite terrain, China

大别山榴辉岩地体以太湖马庙断裂带为南界。该断裂带近东西走向， 向南倾斜。通过对石榴石中 Ｍｇ 含量由核部向边缘增高的生长环带构造的分析和详细的 Ｐ Ｔ 轨迹的计算表明， 断裂带北侧的榴辉岩和南侧的角闪岩及角闪片麻岩均经历了降压增温变质过程。热榴辉岩由地幔深处的折返和地温梯度的升高为可能的热源。

The south boundary of the Dabie eclogite terrain extends west east along Taihu Mamiao faults zone with a south dip Both eclogite and amphibolite along the south of the boundary experienced a temperature increasing and pressure decreasing metamorphic event, as was displayed by Mg increase growth zonation of garnets and P T estimation of mineral assemblages It is implied that the recovered thermal gradient during exhumation of UHP rocks and the hot eclogite terrain exhumed from mantle depths might play a role of heat resource