DIVERSITY PATTERNS IN THE SEQUENCE STRATIGRAPHIC CONTEXT: AN EXAMPLE FROM THE LATE QUATERNARY OF PO PLAIN, ITALY

Sequence stratigraphic processes exert diverse overprints on paleobiological patterns. Here, we examine comparatively sample-level diversity patterns for the highstand and transgressive systems tracts using late Quaternary mollusk associations from Po Plain, Italy. After filtering the data to exclude small samples (n<20), 117 HST and 103 TST samples were analyzed in terms of sample-level diversity patterns. Within each systems tract, samples revealed a comparable bathymetric gradient from high-dominance and high-abundance samples in the most proximal settings (water depth<2m) to low-dominance and low-abundance samples in the more distal settings (water depth >2m). In the proximal setting, the HST and TST sample sets are indistinguishable statistically in terms of dominance and abundance patterns. However, the two systems tracts diverge offshore and dominance and abundance patterns become significantly different in distal setting. These preliminary results suggest that the effects of sequence stratigraphy may vary in magnitude along the depositional profile of a basin exerting differential overprints on the fossil record within single deposystems.