What is Australasian strewnfield?
[[File:Australasian strewnfield.jpg|thumb|300px|alt=An approximate map of the strewnfield.|Australasian [[strewnfield]]. Shaded areas represent [[tektite]] finds.]] The '''Australasian strewnfield''' is the youngest and largest of the [[tektite]] strewnfields. Recent estimates suggest it may cover 10%{{ndash}}30% of the [[Earth]]'s surface.<ref name=povenmire> Povenmire H; Liu W. and Xianlin I. 1999. Australasian tektites found in Guangxi Province, China. ''30th Annual Lunar and Planetary Science Conference''. Houston.</ref> Tektites are gravel-sized bodies composed of black, green, brown, or grey natural [[glass]]. They are formed from terrestrial debris ejected by [[meteorite]] impacts.<ref>French, B.M. 1998. Traces of catastrophe: a handbook of shock-metamorphic effects in terrestrial meteorite impact structures. LPI Contribution #954. ''Lunar and Planetary Institute'', Houston, Texas.</ref> The strewnfield is about c. 790,000-year-old.<ref name=schneider>Schneider D.M. 2002. ''Tektites''. The Meteoritical Society.</ref><ref name=pillans>Pillans, B., Simmonds, P. 2012 Tektites, minitektites and microtektites from the Kalgoorlie region, Western Australia. Australian Regolith and Clays Conference, Mildura, 7–10 February 2012.</ref> It includes most of [[Southeast Asia]] ([[Thailand]], [[Laos]], [[Vietnam]], [[Cambodia]], and [[Southern China]]). The material from the impact stretches across the ocean to include the [[Philippines]], [[Indonesia]], [[Malaysia]], and [[Java]]. It also reaches far west out into the [[Indian Ocean]], and south to [[Australia]] and [[Tasmania]]. Since the 1960s, it has been accepted that the strewn field included [[Hainan]] in southern China to Australia or about 10% of the Earth's surface.<ref name=povenmire/> This was later extended by finds in Africa and Tasmania to 20%. Recent additional finds in northern [[Tibet]] and [[Guangxi]] increased the strewnfield to about 30% of the [[Earth#Surface|Earth's surface]], or almost 150 million km<sup>2</sup>, or about the size of the entire