Microtektites from Victoria Land Transantarctic Mountains

We report on the discovery of a microtektite (microscopic impact glass particles) strewn field from the Victoria Land Transantarctic Mountains, Antarctica. Microtektites were found trapped in the local detritus accumulated in weathering pits and in joints of several glacially eroded summits (approximately 2600 m above sea level [asl]) distributed latitudinally for 520 km. Their physical and chemical properties define a coherent population with a geochemical affinity to Australasian microtektites and compatible Quaternary (super 40) Ar- (super 39) Ar formation age. We therefore suggest that Transantarctic Mountain microtektites (TAMM) define the southern extension of the Australasian strewn field. The margin of the Australasian strewn field is thus shifted southward by approximately 3000 km and the maximum distance from the putative parent impact site in Indochina by approximately 2000 km. This emphasizes the paradox of the missing parent crater of the largest (>10% of the Earth's surface) and youngest tektite strewn field discovered on Earth. Furthermore, TAMM are depleted in volatile elements (i.e., Pb, Na, K, Rb, Sr, Rb, and Cs) relative to Australasian ones, suggesting a possible relationship between high-temperature-time regimes in the microtektite-forming process and high-angle trajectories in the ejecta plume.