纳米级超高压相金红石——大陆深俯冲深度的示踪

大陆深俯冲深度对于了解大陆碰撞造山带中超高压变质岩的折返动力学具有重要意义。文章重点综述了德国含金刚石片麻岩纳米级超高压相 α PbO2 型、斜锆石 (ZrO2 )型结构TiO2 以及金红石其它多形的超显微构造特征、形成的温度压力条件、相变机理以及动力学意义。中国大别—苏鲁超高压变质地区广泛发育金红石副矿物、金红石包裹体或针状金红石出溶体 ,它们为超高压纳米相α PbO2 型和斜锆石型结构TiO2 的存在提供了必要的物质前提。纳米新技术在地球科学中的应用 ,必将给地球科学的发展带来的契机。

NANOMETER-SIZED UHP RUTILE:TRACING THE DEPTH OF CONTINENTAL DEEP SUBDUCTION

The depth of the continental deep subduction is of crucial importance in understanding the dynamics of exhumation process of ultrahigh pressure metamorphic rocks in the continental collision orogen belt. This paper reviews the ultra-microstructural characters, the temperature and pressure of the minerals formation, the mechanism of the phase transformation and the dynamical significance of nanometer-sized ultrahigh pressure phases of TiO 2 with the structural types of α - PbO 2 and baddeleyite, and the other polymorphs of rutile. Rutiles commonly occur as accessory mineral and inclusions in the Dabie-Sulu ultrahigh pressure metamorphic belt. It provided a necessary material premise for the presence of UHP nanometer-sized α-PbO 2-type TiO 2 and baddeleyite-structure TiO 2. The application of nanometer technology will bring a new opportunity to geosciences.