Aerogeophysical constraints for the geodynamic evolution of Dronning Maud Land, East Antarctica

• Main Author: Mieth, Matthias
• Format: Thesis
• Language: unknown
• Published: 2014
• Subjects: Antarc*; Antarctic; Antarctica; DML; Dronning Maud Land; East Antarctica; Ice Sheet
• Online Access: https://epic.awi.de/id/eprint/36693/; https://epic.awi.de/id/eprint/36693/1/Mieth-2014-diss-DMLAerogeophysik.pdf; https://hdl.handle.net/10013/epic.44466; https://hdl.handle.net/10013/epic.44466.d001

The central question of this thesis is: what is hidden under the ice sheet of Antarctica? To unravel the tectonic structure and to study the geodynamic evolution of Antarctica are not only of fundamental geological interest. Knowledge of the amalgamation and break-up of supercontinents provides basic information for studying the evolution of the climate and the biosphere during Earth’s history. Furthermore, knowledge about the tectonic structure of Antarctica is essential for estimating its crustal heat flow, a key parameter when modeling ice flow and future changes of ice sheets. The Antarctic ice sheet is mostly several kilometers thick, and rocks crop out of it in only a few locations to allow direct geological sampling. None of these locations is in the innermost parts of the continent. Hence, regional geophysical reconnaissance and a correlation of its data with geological findings are required for unraveling the tectonic structure of Antarctica. In recent decades, the Jurassic break-up process of Gondwana has been reconstructed based on analyses of the magnetic striping pattern of the oceanic crust, making it apparent that East Antarctica was positioned centrally in this supercontinent between Africa, India, Australia, and New Zealand throughout Paleozoic and Early Mesozoic times. However, fundamental data about the tectonic structure of East Antarctica that would be needed to better understand the assembly of Gondwana in Late Proterozoic and Early Paleozoic times, as well as about earlier collision and break-up processes, are still missing. This study pursues the question of whether the interior of East Antarctica is composed of one or many crustal fragments. Its method objective is to search for the courses of supraregional shear zones and the positions of crustal blocks and their boundaries. For this purpose, the Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (AWI) has undertaken systematic airborne geophysical surveying in the region of Dronning Maud Land (DML) and Coats Land ...