Abstract

A low-latitude distribution of continents may be a prerequisite for the
lobal glaciations that appear to have affected Earth at least twice during
the emergence of animals. However, a preponderance of low-latitude
continents may also make Earth more susceptible to true polar wander, the
process by which the mantle and crust spin relative to the fluid outer
core to maintain rotational equilibrium. I will make a case for a pair of
true polar wander events circa 800 million years ago that started a
cascade of changes in the geochemical cycling between continents and
oceans, and led to global glaciation. Did these changes in climate and
ocean geochemistry finally allow the radiation of animals, or was it the
first animals that modified geochemical cycling and climate?