PHANEROZOIC EARTH SYSTEM EVOLUTION: PALEOZOIC VS. POST-PALEOZOIC INTERACTIONS

Phanerozoic records of seawater chemistry and marine fossil diversity suggest a long-term linkage between global biogeochemical cycling and biotic macroevolution. One aspect of this relationship resides in a bimodal (Paleozoic vs. post-Paleozoic) pattern of variability that is shared among many components of the Phanerozoic Earth system, coinciding with the most recent supercontinent assembly and breakup. Even if any bimodal trend in the mean is filtered out, the nature of the coupling between Paleozoic geochemical and fossil records may be qualitatively different from their coupling in the post-Paleozoic. These evolving interactions are illustrated with analyses of the relationship between oxygen and carbon isotope records from marine carbonates, and of the linkage between marine fossil diversity and the sulfur isotope record.