Areverse fault in Proterozoic rocks along the Grinnell Glacier trail inGlacier National Park (Montan

Areverse fault in Proterozoic rocks along the Grinnell Glacier trail inGlacier National Park (Montana, USA).TheProterozoic Era began 2.5 billion years ago, and ended 543 millionyears ago.  Many important events occurred during this era.Stablecontinents appeared, and began to accrete.  This process took about abillion years.Althoughbacterial life appeared during the preceding Archaean, it is duringthe Proterozoic that we find the first abundant fossils of livingorganisms.  At first, these were mostly bacteria and archaea – butwe can find the first fossils of eukaryotic cells dating to 1.8billion years ago.Thefirst evidence of oxygen build-up in the atmosphere is from about 900million years into the Proterozoic (1,600 million years before thepresent).  This caused many bacterial groups to die off, buteukaryotic forms underwent a population explosion.  These eukaryoticforms included multicellular algae, and the first animals appearednear the end of the Proterozoic. -- source link

More pics about