Main features of megaturbidites in the Eocene of southern Pyrenees

Abstract

Główne cechy megaturbiditów z eocenu południowych Pirenejów Eocene sequences of the Ager-Jaca-Pamplona Basin and Terrades-Ripoll-Cadi Basin Basin in the southern Pyrenees include carbonate megaturbidites. The main features of the megaturbitides are: (i) unusually great thickness. (ii) petrographical composition different from that of their host sequences, (iii) the presence of lower chaotic segment (breccia), and upper organized segment (grading), (iv) large lateral extent, (v) lateral variability of internal organization of beds, (vi) independence of the fan systems, (vii) transport directions different than in normal turbidites. These features are also characteristic of many other carbonate megaturbidites described from various sequences of Alpine Europe. Siliciclastic megaturbidites are less common: they are featured by their smaller thickness and the lack of the lower, chaotic part.