Varanger glaciation
The Varanger Glacial Event (sometimes termed the Stuartian-Varangian with Stuartian being the earlier part) was a world wide
glaciation that occurred around 950-600 Million Years Ago. The population of
acritarchs crashed during this glaciation and it is claimed that
oxygen levels in the
atmosphere increased after the glaciation. There are a number of enigmatic features with regard to this glaciation including indications of glaciation at very low latitudes and the presence of limestones -- normally warm
water sediments above, below and intermixed with glacial deposits. Paleomagnetism seems to indicate very high
continental drift rates leading some geologists to question whether some of the phenomena might be due to
magnetic pole wandering rather than plate motion and low latitiude glaciation. However, cabon isotope analysis indicates that several worldwide glaciations may have occurred. Evidence of the Varanger event is found in various places and times: The
Congo River basin from 950-750Ma and 620-600Ma.
Australia from 800-780Ma and 690-680Ma.
China 800-760Ma, 740-700Ma and 600Ma; Western
North America 850-800Ma,
Sahara 730-650Ma,
Norway 650Ma.
Spitsbergen 593-573Ma. Other known world wide glaciations include the Huronian from 2400Ma to 2100Ma, Andean-Saharan from 450-420Ma, the Karoo glaciation from 360Ma to 260Ma, and the
Cenozoic glaciation which started 30Ma in
Antarctica and may not be over.