Comptes Rendus Palevol, 4, (2005), pp. 653-662.

Multivariate Analysis of Taphonomic Data in Lower Jurassic Carbonate Platform

(Northern Italy)

Jesús E. Caracuel¹, Alice Giannetti² & Paolo Monaco²

¹ Dpto. Ciencias de la Tierra y del Medio Ambiente, Fac. Ciencias, Univ. Alicante, Apdo. 99 San Vicente del Raspeig, 03080 Alicante (Spain). Phone (+34) 965903400 ext.3337; Fax (+34) 965903552; E-mail: jesus.caracuel@ua.es

² Dip. Scienze della Terra, Univ. Studi di Perugia, P.za dell’Università, 06100 Perugia (Italy)

Abstract

Taphonomical analysis on skeletal concentrations and taphofacies has been carried out in the Lower Jurassic deposits of the Trento carbonate platform (northern Italy). The interpretation of the taphonomic categories used has been refined applying three statistical processes to the semi-quantitative values of taphocharacter abundance in eight types of skeletal concentrations. Analysis of correlation allowed the taphocharacters to be subdivided into four genetic categories: 1) paleobiological processes on shelly ground; 2) paleobiological activity on the substrate; 3) mechanical processes induced by currents; 4) infilling processes induced by currents. Cluster and principal-components analysis on the eight types of skeletal concentrations (Skc1a to SkC6a) defined six genetic processes: a) normal waves or weak storm currents (Skc1a-Skc1b), b) high-energy, deep subtidal currents (Skc2-Skc4), c) cannibalistic phenomena induced by very high-energy events (Skc5), d) persistent current action on bioclastic-rich facies (Skc3), e) infilling of open burrows due to high energy events (Skc6), f) high-bioturbation, low-energy conditions (Skc6a). Statistic data analysis is revealed as a helpful method for interpreting relationships among taphonomic features determined by paleobiological and hydrodynamic processes.

Keywords: Numerical analysis, taphofacies, skeletal concentration, taphonomic categories, Lower Jurassic, Trento carbonate platform, northern Italy.