Chapter 1 The Neoproterozoic and Cambrian: A Time of Upheavals, Extremes and Innovations

Abstract

The Neoproterozoic stands out as a period of innovations and upheavals. The extreme palaeoclimatic, palaeoceanographic and biotic events that characterize the Neoproterozoic Era are reviewed, and may ultimately be a result of its unusual tectonic history. The final accretion and subsequent break-up of Rodinia, followed by the amalgamation of Gondwana were probably paramount in influencing Earth's surface environments, although the precise mechanisms remain controversial. Deep-Earth processes, such as mantle avalanches and superplumes, may have been the unheralded engines of a dynamic Neoproterozoic tectonic regime. Rapidly evolving palaeogeography may have in turn contributed to biogeochemical and climatic oscillations, which themselves were likely inextricably linked to biospheric evolution and ultimately the Cambrian explosion. Thus, Neoproterozoic-Cambrian Earth history is a case in point of the complexity and intrigue of the interactions between the deep earth, the lithosphere, the oceans, the atmosphere and the biosphere, helping to improve our current understanding of the Earth system.