Toarcian and Aalenian (Jurassic) ammonites and brachiopods from Monte Kumeta, western Sicily

摘要

A limited fauna (ca. 60 ammonite and a dozen brachiopod specimens) collected from the ferromanganese hardground between the Pliensbachian crinoidal limestone and the Late Bajocian basal beds of the Rosso Aminonitico Inferiore on Monte Kumeta (Western Sicily) indicated several Toarcian and at least one Aalenian ammonite zones. This suggests that the Kumeta locality is an example of places which were free of sedimentation for so long periods in the Toarcian and early Aalenian. In these places drastic subsolution resulted a very irregular, jagged surface on top of the Middle Liassic limestone, while the accumulating ferromanganese crust entombed reworked fossils from the early Toarcian Serpentinum Zone up to the basal Aalenian. In this paper the faunal elements (many as firstly documented from Sicily) are briefly described, and stratigraphically and paleo-geographically evaluated.