Excavating lightning

Not exactly, but close:

A glassy stick made by lightning striking Libyan sands has now been used to date the lightning and detect the ancient climate.

It turns out that the root-like glass "fulgurite" structure made of melted and welded sand from the Libyan Desert contains miniscule [sic] bubbles of trapped gases from the time it was made. These gases, carbon dioxide (CO2), carbon monoxide (CO) and nitric oxide (NO) harbor hints of the type of plants that were zapped along with the sandy ground some 15,000 years ago. . .

Careful analysis of those gases and the weights of the carbon atoms in them reveal the plants were probably the sort which used what’s called C4 photosynthesis — best for plants living in hot, arid climates. This, in turn, implies that the semi-arid Sahel region of today reached much further north during the Pleistocene (1.8 million to 10,000 years ago).

Posted by David on February 1, 2007 12:19 PM