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

维多利亚北部土地的挖掘及其对横贯南极山脉隆起的影响

• 批准号: 404780998
• 负责人: Professor Dr. Frank Lisker
• 金额: --
• 依托单位: Bundesanstalt für Geowissenschaften und Rohstoffe (BGR)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/404780998?language=en
• 关键词: exhumation; northern; Victoria; Land; consequences

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.

该项目旨在重建北维多利亚州的长期景观演变。研究区域占据了太平洋南极转变边缘和南极裂谷系统之间交叉点的跨抗山脉的终止。它由三个地面组成：前寒武纪威尔逊地座，以及古生代的沉积物鲍尔斯和罗伯逊湾地形。这种地质划分反映出高架，内陆高原和高山沿海形态之间的差异地貌对比，并且似乎与适当变化的隆起和挖掘历史相关。在过去的几年中，对威尔逊地座的发掘已被详细重建，我的热循环和结构数据以及地貌观察。这些数据需要在目前的跨北极山附近存在一个持久的中生代盆地，该盆地在两个阶段被挖掘出来。盆地倒置和广泛的剥夺在渐新世早期开始，随后是中新世以来的隆起，高原形成和切口。该项目着重于鲍尔斯（Bowers）和罗伯逊湾（Robertson Bay Terranes）及相关的构造过程的挖掘，以及维多利亚北部北部地区的景观对比的发展。该项目的结果将大大增强我们对跨二行山脉隆升的知识和南极裂谷系统的演变，为解释罗斯海问题中的地震层学的解释以及提高我们对系统构造 - 气候 - 气候 - 岩性学的理解做出了新的论点。它还对南极洲和澳大利亚之间的冈瓦纳破裂时间和冈瓦纳破裂过程产生一阶后果，并将为南半球的长期气候重建提供必不可少的背景参数。从方法上讲，该项目依赖于BGR Expedition Ganovex XIII（2018/19）期间的结构地质，地下室的地质观察和采样，覆盖岩石和脆性结构。随后的热量研究研究包括裂变轨道（FT）和（U-TH-SM）/HE在适当和锆石上进行分析，然后进行热史建模以及最上皮等温线模式的三维重建。