Microtektites from Victoria Land Transantarctic Mountains

Abstract

We report on the discovery of a microtektite (microscopic impact glass particles) strewn
\nfi eld from the Victoria Land Transantarctic Mountains, Antarctica. Microtektites were found
\ntrapped in the local detritus accumulated in weathering pits and in joints of several glacially
\neroded summits (~2600 m above sea level [asl]) distributed latitudinally for 520 km. Their
\nphysical and chemical properties defi ne a coherent population with a geochemical affi nity to
\nAustralasian microtektites and compatible Quaternary 40Ar-39Ar formation age. We therefore
\nsuggest that Transantarctic Mountain microtektites (TAMM) defi ne the southern extension of
\nthe Australasian strewn fi eld. The margin of the Australasian strewn fi eld is thus shifted southward
\nby ~3000 km and the maximum distance from the putative parent impact site in Indochina
\nby ~2000 km. This emphasizes the paradox of the missing parent crater of the largest
\n(>10% of the Earth’s surface) and youngest tektite strewn fi eld discovered on Earth. Furthermore,
\nTAMM are depleted in volatile elements (i.e., Pb, Na, K, Rb, Sr, Rb, and Cs) rela tive to
\nAustralasian ones, suggesting a possible relationship between high-temperature–time regimes
\nin the microtektite-forming process and high-angle trajectories in the ejecta plume.