Thermochronological and structural investigation accompanying LEGENDS: I - The morpho-tectonic evolution of Sri Lanka

斯里兰卡显生界的地质演化很难受到约束，因为没有记录到构造和/或火成岩过程，也没有保存大规模的“贡德瓦南”沉积矿床。为了克服这一不足，我们的研究将采用低温热年代学方法(裂变径迹/FT和(U-Th)/He分析)和沿斯里兰卡深部地震传说断面的构造调查。这种方法将上地壳的冷却/剥蚀模式与下面的地壳结构联系起来，从而能够对区域显生宙地质历史和长期地貌演化进行详细的量化和成因解释。该项目的具体主题是：(1)地形的长期发展；(2)马达加斯加、印度、斯里兰卡和南极东部之间冈瓦纳断裂的过程，以及随后斯里兰卡大陆边缘的演化；(3)构造活动的年代及其对剥蚀的影响；(4)古地温梯度的建立；(5)斯里兰卡冈瓦纳沉积物的沉积和各自盆地的演化；以及(6)区域断裂模式的分析。

The Phanerozoic geological evolution of Sri Lanka is poorly constrained since no tectonic and/or igneous processes are recorded, and no large-scale "Gondwanan" sedimentary deposits are preserved. To overcome this deficiency, our study will apply low-temperature thermochronological methods (fission track/ FT and (U-Th)/He analysis) and structural investigations along the transect of the deep seismic LEGENDS traverse across Sri Lanka. This approach links the upper crustal cooling/ denudation pattern with the structure of the crust beneath, allowing a detailed quantification and genetic interpretation of the regional Phanerozoic geological history and long-term landscape evolution. Specific topics of the project are (1) the long-term development of the topography; (2) the course of the Gondwana breakup between Madagascar,.India, Sri Lanka and East Antarctica, and the subsequent evolution of the Sri Lanka continental margins; (3) the dating of tectonic activities and their influence on denudation; (4), the establishment of the paleogeothermal gradient; (5) the deposition of Gondwana sediments in Sri Lanka, and the evolution of the respective basin; and (6) the analysis of the regional fault pattern.