The exhumation of northern Victoria Land and consequences on the uplift of the Transantarctic Mountains

该项目旨在重建维多利亚北部土地的长期景观演变。研究区位于太平洋南极转换边缘与南极西部裂谷系交汇处的横贯南极山脉的末端。它由三个地体组成：前寒武纪克拉通威尔逊地体和古生代元沉积鲍尔斯地体和罗伯逊湾地体。这种地质划分反映在高架、深切的内陆高原和高山海岸形态之间独特的地貌对比上，并且似乎与相当不同的隆起和挖掘历史有关。在过去的几年中，通过热年代学和构造数据以及地貌观测，对威尔逊地的发掘工作进行了详细的重建。这些资料要求在现今横贯南极山脉附近存在一个长期存在的中生代盆地，该盆地分两个阶段被挖掘出来。早渐新世开始盆地反转和大面积剥蚀，中新世开始隆升、高原形成和切割。该项目侧重于鲍尔斯和罗伯逊湾地体的挖掘和相关的构造过程，以及维多利亚北部地区景观对比的发展。该项目的研究成果将大大提高我们对南极横贯山脉隆升和南极西部裂谷系统演化的认识，为罗斯海海槽地震地层学的解释提供新的论据，并提高我们对系统构造-气候-岩性的理解。它还对南极洲和澳大利亚之间冈瓦纳破裂的时间和过程具有一级影响，并将为南半球的长期气候重建提供必要的背景参数。在方法上，该项目依赖于BGR探险GANOVEX XIII（2018/19）期间的构造地质学，地貌观测和基底，覆盖岩层和脆性结构采样。随后的热年代学研究包括对磷灰石和锆石的裂变径迹（FT）和(U-Th-Sm)/He分析，然后是热历史建模和最上层地壳等温线模式的三维重建。

The project aims to reconstruct the long-term landscape evolution of northern Victoria Land. The study area occupies the termination of the Transantarctic Mountains at the intersection between the Pacific Antarctic transform margin and the West Antarctic Rift System. It is composed of three terranes: the Precambrian cratonic Wilson Terrane, and the Paleozoic metasedimentary Bowers and Robertson Bay terranes. This geological division is reflected by a distinctive geomorphological contrast between elevated, deeply incised inland plateaus and an Alpine coastal morphology, and appears to correlate with considerably varying uplift and exhumation histories. Exhumation of the Wilson Terrane has been reconstructed in detail during the last years my means of thermochrono¬logical and structural data, and geomorphological observation. These data require the existence of a long-lasting Mesozoic basin in the vicinity of the present Transantarctic Mountains that was exhumed in two stages. Basin inversion and extensive denudation commenced in the Early Oligocene, followed by increased uplift, plateau formation and incision since the Miocene. The project focuses on the exhumation of the Bowers and Robertson Bay Terranes and related tectonic processes, as well as the development of the landscape contrast across northern Victoria Land. The outcome of the project will enhance substantially our knowledge about the uplift of the Transantarctic Mountains and the evolution of the West Antarctic Rift System, contribute new arguments for the interpretation of the seismic stratigraphy in the Ross Sea troughs, and improve our understanding of the system tectonics – climate – lithology. It also has first-order consequences on timing and course of Gondwana breakup between Antarctica and Australia and will provide essential background parameters for the long-term climate reconstruction of the southern hemisphere. Methodologically, the project relies on structural geology, geomorphological observation and sampling of basement, cover rocks and brittle structures during the BGR expedition GANOVEX XIII (2018/19). Subsequent thermochronological research includes fission track (FT) and (U-Th-Sm)/He analyses on apatites and zircons, followed by thermal history modelling and a three-dimensional reconstruction of the isotherm pattern of the uppermost crust.