Subice geology of Dronning Maud Land, East Antarctica, revealed by UPb zircon study of metasedimentary rocks of the Shackleton Range

Project description
Norway claims a large region in Antarctica, Dronning Maud Land, which is seven times larger than Norway. However, it is largely ice-covered such as most of Antarctica. Therefore, we know comparatively little about this huge region of the Antarctic continent. There are several ways to explore the subice geology of ice-covered regions, such as drilling, connecting geology with geophysics as well as provenance studies of sedimentary rocks and glacial drift. In this project we will undertake a U-Pb zircon provenance study of meta-sedimentary rock samples from the Shackleton Range at the southwestern periphery of Dronning Maud Land.

The Shackleton Range is a poorly studied region, where Norwegian geologists have never been so far. It has been explored last at the end of the past century. Tectonically, it is however a key region for the unravelling of the tectonics of East Antarctica, where along a Pan-African suture zone different crustal blocks with African and Australian affinities appear to meet. Preliminary detrital zircon analyses of the detrital cover rocks provide very interesting results, indicating strong Paleoproterozoic age components that are otherwise absent in the close-by African extension into East Antarctica.

In order to get a deeper understanding of the crustal components that are involved in the tectonic evolution of the region, we will investigate the detrital U-Pb zircon fingerprint of metasedimentary rocks of the two major crustal units, namely the Northern and Southern blocks that are represented by the Stratton-Pinoneers groups and the Read group respectively. Metasediment samples of these two groups are available at the German Polar Sample archive in Berlin, where ca. 10 samples will be collected. Back in Bergen these samples will be crushed and processed for mineral separation. Thereafter, zircon separates will undergo cathodoluminescence imaging, followed by U-Pb analyses at our LA-ICPMS facility at GEO. Additional Lu-Hf analyses will be conducted at the Bundesanstalt fuer Geowissenschaften (BGR), Hannover, Germany. In a regional context the new data will be compared and integrated with comparable studies across Antarctica and its closest neighbors in Gondwana, which will involve significant literature research and some GIS work.

Geological overview map of the Shackleton Range, showing the targeted metasedimentary rocks of the Stratton-Pioneers groups, as well as the Read group.

Photo:

Will et al. (2009)

Proposed course plan during the master's degree (60 ECTS):
GEOV205
GEOV251
GEOV241
GEOV242
GEOV302
GEOV362
STAT110

Field- lab- and analysis work
U-Pb zircon analyses