Stratigraphic Paleobiology of Carbonate Systems

Stratigraphic paleobiology is a newly established interdisciplinary approach, which has demonstrated that the fossil record is a joint expression of biotic and stratigraphic change, and all inferences from it must be grounded in a solid understanding of the stratigraphic context. Fossiliferous strata can be found in all depositional systems (e.g., marine, terrestrial, or lacustrine; siliciclastics or carbonates), each having a unique characteristic timescale and set of external controls, which govern the accumulation of sedimentary particles, including fossils. Consequently, the same biotic changes are preserved differently across depositional systems. While carbonate systems form a large portion of the fossil record, most studies in stratigraphic paleobiology have focused on siliciclastic systems and are not easily generalizable. As they are predominantly formed by living organisms, carbonates are both fossils and record, opening the opportunity to study the co-dependency of life and its environment. Here, we explore the stratigraphic paleobiology of carbonate systems by combining simulations of carbonate platform and ramp geometries with synthetic fossil records. We explore the preservation of extinction patterns and rates spatially and across geometries. By examining stratigraphic biases in isolation (unconformity and condensation, ecology, and abundance biases), we find characteristic differences between ramp and platform geometries due to their differential response to sea level change, spatial variability, and differences in ecological clines. Differences in the structure of the fossil record between platform geometries are traceable to the contribution and properties of the carbonate producing organisms (carbonate factories), showing that preservation of earth system data in carbonate systems will vary both latitudinally and temporally or as a result of major perturbations of the biogeosphere. Our results show that while general rules on the structure of the fossil record can be derived for entire depositional systems, accounting for the geological and ecological dynamics of a particular sedimentary basin can hugely refine interpretations of the fossil record. That is particularly true for biogenic and biologically-mediated sediments.