Complex multicellular life arose in a geological nanosecond (within about 3 million years) of the termination of Earth’s last of 3 protracted global glaciations or “snowball Earths”. An explosion in biological diversity followed and ushered in a 20-fold increase in atmospheric oxygen. The world changed in a fundamental way almost overnight. The geological context for this biological and climatic bifurcation was the breakup of the supercontinent Rodinia: a tectonic bifurcation of sorts. The confluence of events make this period one of the richest in Earth history. We don’t have a lot of time for this story but it is one you should know about. We will read just a couple of papers and explore how the evidence is constructed for this story: How the geological and geochemical data permit such a story. This is the first of 3 modules in which we look carefully at time series data and explore conceptual or quantitative models applied to make sense of it.
Learning Goals for This Module (TBA)
Reading (more to follow, depending on where we are):
Hoffman and Schrag: Snowball Earth
Hoffman: The Pan-glacial state
