Rockscape | Geology

Out of the far western icefield of Western Dronning Maud Land (WDML) rise the Annandagstoppane nunataks. The name originates from the Norweigian word for the day after Christmas (i.e., Boxing Day) when these nunataks were first discovered.

Archean-age granite exposed at Annandagstoppane.

There is not much rock exposure in East Antarctica, and little of that exposure is Archean in age. Three small and not very prominent Annandagstoppane nunataks have the distinction of exposing the only outcrops of Archean-age rocks in Antarctica outside of Enderby Land. (The largest of the three nunataks is shown in the photo, which was taken in 1995 when I was collecting samples for research purposes.) The three nunataks expose granitic rocks, informally described as the Annandagstoppane granite. These were the oldest known rocks in all of Antarctica until older rocks were identified in Enderby Land.

Is it possible that the Annandagstoppane granite is part of the basement upon which the younger Mesoproterozoic-age supracrustal rocks in the area were emplaced? After the breakup of Gondwana, did this part of East Antarctica retain a fragment of the Kaapvaal Craton?