Geology of the Vardeklettane Terrane, Heimefrontfjella (East Antarctica)

Abstract: In the southwest of the Heimefrontfjella mountain range a granulite-
facies terrane is exposed in the small Vardeklettane nunataks. The Vardeklettane
Terrane extends, however, at least 65 km farther WNW to the nunatak
group of Mannefallknausane, where comparable granulites are exposed. The
terrane is composed of mafic and felsic granulites, leucogranite orthogneiss
and metasedimentary rocks. The maximum deposition age of the latter is
constrained by detrital zircon U-Pb data ranging from 2000 to 1200 Ma
whereas the leucogranite gneiss gave a late Mesoproterozoic crystallization
age of 1135 Ma. The Vardeklettane Terrane is unique as being the only part of
the otherwise juvenile Late Mesoproterozoic basement of Heimefrontfjella to
have a Paleoproterozoic crustal component. Structurally, the terrane is separated
from the main range by the Heimefront Shear Zone.