CONNECTING GEOLOGY AND GEOPHYSICS: THE GEODYNAMIC EVOLUTION OF DRONNING MAUD LAND FROM RODINIA TO GONDWANA

• Main Authors: Läufer, Andreas, Jacobs, Joachim, Elburg, Marlina, Ruppel, Antonia, Kleinhanns, I., Mieth, Matthias, Jokat, Wilfried, Estrada, Solveig, Henjes-Kunst, Friedhelm, Eagles, Graeme, Krohne, N, Damaske, Detlef, Clark, Chris, Andersen, Tom, Lisker, Frank
• Format: Conference Object
• Language: unknown
• Published: Alfred Wegener Institute for Polar and Marine Research 2015
• Subjects: Antarc*; Antarctic; Antarctica; Dronning Maud Land; East Antarctica; Polar Research
• Online Access: https://epic.awi.de/38539/1/BzPM_0690_2015.pdf; https://epic.awi.de/id/eprint/39617/; https://epic.awi.de/id/eprint/39617/1/Laeufer_etal_DGP2015.pdf; https://hdl.handle.net/10013/epic.46790; https://hdl.handle.net/10013/epic.46790.d001

East Antarctica consists of a number of cratonic fragments that amalgamated along distinct orogenic belts in late Neoproterozoic to early Palaeozoic times. These mobile belts include the c. 640 to 500 Ma old East African-Antarctic Orogen (EAAO) and the Kuunga Orogen, which seem to converge in Dronning Maud Land in the Atlantic sector of Antarctica. The polymetamorphic basement of Dronning Maud Land is characterized by rocks with Grenville-age protolith ages of c. 1130 to 1000 Ma in the west and rocks with early Neoproterozoic protolith ages of c. 1000 to 900 Ma in the east. These two provinces are separated by the prominent Forster Magnetic Anomaly, which is therefore interpreted to represent a suture zone. Four joint AWI-BGR international expeditions within the WEGAS (West-East Gondwana Amalgamation and Separation) and GEA (Geodynamic Evolution of East Antarctica) programmes between 2010 and 2015 have provided new combined geological and geophysical data that reveal a complex crustal architecture between central Dronning Maud Land and Lützow-Holm-Bay. The magnetic anomaly pattern changes significantly east of the Forster Magnetic Anomaly with apparently no indication of Maud-type crust. Particularly, the GEA II campaign (2011-12) targeted a series of previously unvisited nunataks in the largely ice- covered Borchgrevink-Isen between central Dronning Maud Land and Sør Rondane from Urna and Sørsteinen in the west to Blåklettane and Bergekongen in the east. This region is characterized by NW-SE trending distinct linear magnetic anomalies. This pattern is referred to as the SE Dronning Maud Land Province and was previously interpreted as a fragment of potentially older cratonic crust south of an Ediacaran to Cambrian mobile belt that crops out in Sør Rondane. New SHRIMP/SIMS U-Pb zircon ages and geochemical analyses, however, indicate that this region consists of Rayner-age (c. 1000 to 900 Ma) juvenile arc and metasedimentary cover rocks, which were intensely reworked by medium- to high-grade metamorphism and ...