Catastrophism is back on the nose at George Howard's place – go to http://cosmictusk.com/wow/ … and one word says it all as unusual silicate glass was found in the Atacama Desert in northern Chile. The melted rock fragments litter the ground at several locations. They possess a stable remanent magnetism carried by fine grained magnetite aquired during cooling (of the heated silicate). Basically, some sediments were heated to form a bank or layer up to 20cm thick, and they were heated up by very high temperatures. The silicate glass also contained iron sulphides, also an indicator of great heat. In other words a very hot event occurred over Atacama – we are not talking about an impact site.
The mineralogical observations do not suggest an impact, volcanic activity, or lightning as the vector but do point towards a thermal event such as an airburst (a meteor exploding in the atmosphere above the Atacama). Charcoal produced a C14 date between 12 and 13 thousand years ago – the Younger Dryas boundary is inferred.
See the comments on the dynamics of an airburst. Some good stuff here by several of the regulars. The vitrified forts of Scotland also get a mention – not sure if this advances their cause. All cutting edge stuff – with an emphasis on the edge.