Sunday, May 03, 2015
The Mesozoic ended with a splat
But what about a vastly older time?
Archean life was breathing algal mat
Did asteroids destroy them in their prime?
The spherule layer in the Kuruman
Contains iridium, enriched by mass.
Though seared in orogenic frying pan
Stilpnomelane was once an impact glass.
The Pilbara, a continent away
Contains the same meteoritic trace
The world rained fire on that fateful day,
A hail of red-hot glass from outer space.
Yet, younger sediments are undisturbed
The hydrologic cycle’s unperturbed.