Carbon and carbon isotope mass balance in the Neoproterozoic Earth system

Abstract

The Neoproterozoic Earth system was significantly different from the modern world, as evidenced by extraordinary carbon isotope fluctuations that defy conventional explanation. Because Earth's carbon and oxygen budgets must be balanced on very long time scales (>105 years), such prolonged excursions can best be explained by invoking a vast pool of dissolved organic matter (DOM) in the world's oceans and its remineralisation by surplus oxidant after pyrite burial. The episodic waxing and waning of a DOM reservoir helps to explain the occurrence and timing of extreme climate events during the Neoproterozoic Era. Ecological dominance by eukaryotes, such as animals and algae, arose from a series of opportunistic radiations of aerobic life forms during periods of net DOM remineralisation and oxygenation.