地形地貌发育时间与古地形反演

地形地貌是构造过程与地表过程等相互竞争的结果，古地形重建与地貌演化研究将有助于理解这些过程及其相互作用关系。传统的地形地貌演化研究多基于14C、释光、磁性地层等定年手段，定性或半定量地分析构造活动与地表侵蚀对地形地貌发育的影响。随着相关技术手段的发展，低温热年代学方法已不仅仅局限于构造地质学领域的造山带构造-热演化历史研究，目前已用于重建地形地貌演化历史。基于这一背景，在概述低温热年代学基本原理的基础上，结合自己的研究，主要介绍了该方法在地形地貌发育时间、古地形反演等方面的研究进展以及研究中需要注意的一些问题。文章最后指出，寻求具有更低封闭温度的低温热年代学测年体系是这方面研究的努力方向。

TIMING OF PALEOTOPOGRAPHIC AND GEOMORPHOLOGIC EVOLUTION AND PALEOTOPOGRAPHIC RECONSTRUCTION BY LOW-TEMPERATURE THERMOCHRONOLOGIC APPROACHES

Tectonism together with surface processes create terrain (topography and geomorphology), and thus paleotopographic reconstruction and geomorphologic studies are helpful to the understanding of these processes and their co-relationships. Usually geomorphological dating methods such as optically stimulated luminescence dating, thermoluminescence dating, radiocarbon dating, and magnetostratigraphy are used to qualitatively or semiquantitatively define the tectonic activation and climate change in the evolutionary history of geomorphology and topography. As mineral grains, such as apatite and zircon, are considered, low-temperature thermochronology is the choice to define the cooling age of the rocks. Popular applications of this method has contributed greatly to the study of tectonic-thermal history and provenance analysis as well as paleotopographic reconstruction. Here we first review the principles of low-temperature thermochronology and then illustrate the application of this method in the following fields related with paleotopography:(1) Timing of paleotopographic evolution and (2) Paleotopographic reconstruction. We also note that low-temperature thermochronometry with the lower closure temperature will be the important mean for resolving the problem on the evolution of shallow crust associated with surface processes.