An expanded record of Early Cambrian carbon cycling from the Anti-Atlas Margin, Morocco

We present a delta C-13 record from the Anti-Atlas mountains of Morocco and place it in the context of a detailed regional tectonostratigraphy. We place the litho- and chemostratigraphic record in a temporal framework using precision U-Pb zircon geochronology of ashes interbedded with the same carbonate units that provide delta C-13 data. The variations in delta C-13 of carbonate occur on a wide range of time scales, Suggesting that different mechanisms are involved, including non-steady state release of isotopically depleted carbon reservoirs oil short (<100 000 years) time scales and changes in nutrient recycling and organic carbon burial oil longer (>1 Ma) time scales. Through a correlation with more fossiliferous, albeit condensed, section in Siberia, we examine the pattern of Cyclic delta C-13 variation in the context of the reappearance and diversification of skeletonized metazoa during the Early Cambrian.