Author/Authors :
Mahaney، نويسنده , , William C. and Krinsley، نويسنده , , David، نويسنده ,
Abstract :
Lightning and cosmic impacts on bedrock, sediment cover and vegetation cause, and have caused through geologic time, almost instantaneous high energy discharges that produce extreme heating to many hundreds or a few thousand degrees Celsius. The effects of these cataclysmic events leave an imprint in surface material, such that much of it becomes physically changed and carbonized; primary and secondary minerals become welded together and/or coated with carbon providing a food source for microbes which invade the altered material. Here we present a summary of fired rock and sediment covers from the Andes (cosmic impact), the Alps (lightning, fired rock) and southern Ontario, Canada, where lightning toppled a red pine (Pinus resinosa), thus altering the cellulose internal fiber and bark. Electrostatically levitated minerals from the tree roots/soil, transported upward a considerable distance, became embedded in the outside and inside of the bark. Cellulose, quartz and various plagioclases were melted, the former producing deformed sheets of Si, the latter pure metallic Na. Mineral artifacts of extreme heating events catalogued here might be used in environmental reconstruction efforts when problematic bedrock and sediment covers offer no alternative explanation.
Keywords :
Fired sediments , Cosmic , Time-stratigraphic markers , Lightning/volcanic-induced firing events