Sedimentology and hydrodynamics of mixed (siliciclastic-bioclastic) shallow-marine deposits of Acerenza (Pliocene, Southern Apennines, Italy)

• DOI: 10.3301/ijg.2011.36
• Publication Date: 2021-07-20T13:59:17Z
• Authors: Chiarella, Domenico
• Keywords: Siliciclastic; Terrigenous sediment

During the Pliocene, along Apennines front of Southern Italy (Acerenza area), a sector wedge-top basin hosted shallow-marine siliciclastic-carbonate (-bioclastic) sedimentation. Sediments consist mixed arenites and rudites forming an up to 30 m thick unit. Based on recognition textural features, sedimentarystructures, degree segregation between siliciclastic bioclastic particles, facies analysis revealed 10 grouped into 5 associations. They suggest occurrence either wave or current dominated environments, showing different degrees heterolithic particles.The depositional system was characterised by gentle sloping profile irregularly undulated syndepositional folds. Waves shallowest areas terrigenous fraction derived mainly from erosion substrate (arenaceous) rocks. These were located at top anticlines depths corresponding that upper shoreface classic coastal profile. The fragmentationof in situ heterozoan skeletal-carbonate factory. Almost constant waves activity prevented fractions lower zones. In relatively deeper environment (offshore transition), persistent unidirectional currents dominated, with development tide-influenced 2D 3D dunes. Repeated oscillations water column sheltered produced modulation velocity favouring dune foresets. Finally, deepest (offshore), pervasive bioturbation causing unsegregation fractions.