The earth science battlefields are as fierce as any other. One highly contested paradigm is the peopling of America. And quite unwillingly, a major feature in that battle is poor innocent Virginia Steen-McIntyre, who was so unfortunate to date volcanic ash layers that covered some paleo indian stone tools to an ago of some 260,000 years That story is http://disputatio.com/articles/006-1.pdf [Broken] and it took 15 years of ardent battling to get those results published in: Steen-McIntyre, Virginia; Fryxell, Roald; Malde, Harold E (Jul 1981) Geologic evidence for age of deposits at Hueyatlaco archeological site, Valsequillo, Mexico . Quaternary Research, vol. 16, no.1, pp.1-15 As everything bound to get on the net eventually, this paper is now available too, at least the first ten pages: http://www.valsequilloclassic.net/VSM/quaternary_research/quaternary_research_1981.pdf [Broken] But much more on her website here: http://www.valsequilloclassic.net/VSM/index.htm [Broken] I love those little anomalies, challenging mainstream science and 260,000 old Clovis type flute points (normally 12-11,000 years old) is outrageous. However, looking at (studying) the pictures and reading the story, I'm not so sure anymore if there could be a simple down to earth explanation. That mud mixed with the tephra layer is suspicious Those tools may not be older than 260,000 years at all. They may in fact have any age.