Thermochronological data from the Dronning Maud Land Mountains, East Antarctica – a review

The paleo-topography of East Antarctica is highly relevant for the development of the East Antarctic ice-sheet. It is likely that the 1500 km long, coast-parallel Dronning Maud Land Mountains have resulted in a significant amount of precipitation prior to the initiation of the 34 Ma glaciation history of East Antarctica. Due to this, the paleo-topography should be used as an important input parameter for the glaciation history. The amount of quantitative measurements for the exhumation history of Antarctica is very limited as 98% of the continent is covered by ice. However, since the onset of thermochronological studies in the Dronning Maud Land Mountains in 1992, the area has been a subject of several thermochronological studies. The first thermochronological studies from Heimefrontfjella and Mannefjellknausane recorded a Jurassic thermal event associated with the Jurassic flood basalts related to the Karoo mantle plume and the rifting between East Antarctica and East Africa. Thermochronological data from Heimefrontfjella and Mannefjellknausane published by Jacobs and Lisker (1999) indicated that the Mesoproterozoic basement and the Permian sandstones were covered by 2000 meters of Jurassic flood basalt. In the Mühlig-Hofmann Mountains and the Gjelsvikfjella to the E, no significant Jurassic thermal event have been recorded. However, a combined titanite and apatite study by Emmel, et al. (2009) did not record any significant Jurassic thermal event in the Gjelsvikfjella and Mühlig-Hofmann Mountains. This has been used as a constraint for the lateral extent of the flood basalts. Also, the thermochronological analyses presented in Jacobs and Lisker (1999) indicated that the AFT ages get progressively older towards the SE. Based on these analyses; paleo-isotherms dipping towards the SE were suggested. In addition to the already published data, new, unpublished AHe data from a transect of the northern part of Jutulstraumen show relatively young ages at the rift flanks (~50 Ma) and progressively older ages further away from the rift flanks, indicating significant Cenozoic erosion (Ksienzyk et al., unpublished data). This is the basis for presently ongoing thermochronological studies.