A POSSIBLE METEORITE IMPACT INITIATION OF THE CAMBRIAN

I propose that a huge meteorite impact in central Australia 545 million years ago initiated the Cambrian explosion of life by a layer of dust on snow ball Earth. Connelly has discovered evidence of a huge crater about 310 miles in diameter centered southwest of Alice Springs, Australia, at the Ayers Rock (see http://www.mapcis.net/mapcis_research.html), Ayers Rock is at 26 21 south, 131 02 east. There is a ring of disruption 430 miles in diameter around that and another ring of disruption 1300 miles in diameter. The antipode for that is east of Haitiat 26 21 north, 49 west.

Evidence for the crater includes large arcing deposits of pseudotachylite found only at impact sites, an extensive web of ground faults radiating out from the impact site, worldwide deposits of feldspar and zircon dated 545 million years ago that share the exact age (1.21 billion years) of the zircon found at the crater’s center, deposits of osmiridium that is a rare natural alloy of osmium and iridium in eastern Australia, New Zealand and New Caledonia and found there at the Cambrian/Pre Cambrian boundary.

The impact was so massive that there was a 1300 mile wide disruption around the crater. There is some lava near the periphery of the disruption. This exception to lack of lava at meteorite impacts elsewhere may be related to the enormous area of the disruption. The periphery disruption was far from the area of lighter crust caused by impact removal plus melting of the crust, which undoubtedly tends to usually prevent upwelling of lava.

This impact could have been the cause of the initiation of the Cambrian period by warming up of the snowball Earth by a worldwide deposit of dust on iced areas. Dust on ice is a very important cause of ice melting (see http://charles_w.tripod.com/climate.html). Once the ice on the ocean melted, the increased sunlight absorption there could have permitted large release of carbon dioxide from organic matter that could then decompose and methane from methane ice. Thus there would be a positive feedback from a greenhouse effect in addition to the heating of bare soil. Also this vast amount of dust was probably an important source of increased fertility for the oceans by direct deposition and erosion on land, which oceans were the primary location for life at that time and thus spark the Cambrian explosion of life.