[1] The high elevation and rugged relief (>3 km) of the Gamburtsev Subglacial Mountains (GSM) have long been considered enigmatic. Orogenesis normally occurs near plate boundaries, not cratonic interiors, and large-scale tectonic activity last occurred in East Antarctica during the PanAfrican (480-600 Ma). We sampled detrital apatite from Eocene sands in Prydz Bay at the terminus of the Lambert Graben, which drained a large pre-glacial basin including the northern Gamburtsev Mountains. Apatite fission-track and (U-Th)/He cooling ages constrain bedrock erosion rates throughout the catchment. We double-dated apatites to resolve individual cooling histories. Erosion was very slow, averaging 0.01-0.02 km/Myr for >250 Myr, supporting the preservation of high elevation in interior East Antarctica since at least the cessation of Permian rifting. Long-term topographic preservation lends credence to postulated highelevation mountain ice caps in East Antarctica since at least the Cretaceous and to the idea that cold-based glaciation can preserve tectonically inactive topography.
The Gamburtsev Subglacial Mountains of East Antarctica are among Earth's most enigmatic mountain ranges. They are situated in the middle of Antarctica, buried under hundreds of meters of ice, and reach an elevation of more than 3000 m. These characteristics have given rise to speculation about their origin and composition, in particular whether they are a hotspot or remnants of ancient orogenic events. We studied fluvio‐deltaic sands from ODP Site 1166 in Prydz Bay which were deposited prior to the onset of East Antarctic glaciation to address the question of their origin. Results for U‐Pb dating of detrital zircons reveal an important age population of ∼530 Ma, which is accompanied by a dominant 40Ar/39Ar age population of ∼519 Ma for detrital hornblendes. The data show no sign of young volcanic contributions, suggesting an old continental origin of the mountains, leaving as enigmatic the cause of their great height and size.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.