Deposition of megabeds (megaturbidites) and sea-level change in a proximal part of the Eocene-Miocene flysch of central Dalmatia (Croatia)

Some carbonate megabeds of the proximal part of the Dalmatian Eocene-Miocene flysch basin (eastern Adriatic Sea) are underlain and overlain by conglomeratic fan deltas, whereas thinner-bedded turbidites interfinger with fan-delta conglomerates. Fan deltas and interfingering turbidites are interpreted as having been deposited during lowstand(s) and early sea-level rise(s), whereas deposition of megabeds is attributed to periods of accelerated sea-level rises that aborted growth of fan deltas. Attribution of megabeds to periods of sea-level rise is based on the following observations: (1) they overlie some conglomeratic fan deltas, (2) skeletal and lithic debris in megabeds originated by subaerial weathering of older sediments, and (3) their large thickness indicates considerable primary accumulation of debris and low frequency of flows. Sea-level changes inferred from megabeds are different from those related to thinner classical turbidites, and distinction of the two is important for sequence stratigraphy in deep-marine sediments.