Paleoproterozoic geology

severe glaciation during the Paleoproterozoic Era, possibly due to the Oxygen catastrophe, leading to a "Snowball Earth"

thumb|A shungite-bearing rock (left) and solid bitumen shungite (right) Shungite is either a diverse group of metamorphosed Precambrian rocks all of which contain pyrobitumen, or the pyrobitumen within those rocks. It was first described from a deposit near Shunga village, in Karelia, Russia, from where it gets its name. Shungite is most widely known for pseudoscientific and quack medical claims about its uses in medicine and technology, where it is claimed to have properties ranging from nebulous health benefits to blocking 5G radiation.

suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland