Proterozoic eonothem

The Proterozoic Eonothem represents the younger of the two divisions of Precambrian time, spanning from 2.5 billion to 541 million years ago. It is further divided into the Paleoproterozoic, Mesoproterozoic, and Neoproterozoic eras. Unlike later geologic periods, the Proterozoic lacks abundant fossils, making subdivision difficult. Instead, relative chronologies are established using unconformities and crosscutting dikes, alongside isotopic age dating.12

During the Proterozoic, significant geological events occurred, including the breakup and reassembly of supercontinents like Rodinia. Large amounts of sedimentary rocks such as quartzite, carbonate, and shale were deposited. Plate-tectonic processes were active, leading to the formation of mountain belts through continental collisions. Life also began to evolve, with evidence of bacteria, blue-green algae, and the first oxygen-dependent animals, the Ediacara fauna, appearing during this eon. Proterozoic rocks are valuable sources of metallic ores, including iron, gold, copper, uranium, and nickel.134