Tracking sand-fairways through a deformed turbidite system: the Numidian (Miocene) of Central Sicily, Italy

Understanding ancient deep-water sedimentary systems that accumulated at complex plate boundaries requires confronting the stratigraphic record of deformed sedimentary successions by tracking sand-fairways and identifying original relationships in later deformed sequences. Here, we investigate the Numidian turbidite system (early to mid-Miocene) of Central-East Sicily to explore a deep-water sedimentary system deposited at an active thrust belt on the Central Mediterranean. Turbidites include multi-metre thick-bedded, ultra-mature quartz sandstones that were sourced from North Africa and are now deformed and dismembered within the Apennine-Maghrebian orogen. To date, much research has focused on the little-deformed sections that sample discrete parts of the original turbidite pathways. Yet the bulk of these systems are represented by deformed successions and these have attracted little modern sedimentological and stratigraphic investigation. We present new data based on field mapping, sedimentological/structural fieldwork, and biostratigraphy (planktonic foraminifera and nannofossils) that focus on the Numidian turbidites of Central-East Sicily. Thickness and facies variations, together with evidence of large-scale sediment bypass and local substrate reworking, characterise the Numidian turbidites of the study area, consistent with a partially confined turbidite system. Our work demonstrates that the Numidian turbidite system accumulated across active structures and these provided tortuous, evolving corridors through which turbidity currents were routed, transporting coarse sand over many hundreds of km. These results provide insight on structurally confined turbidites in analogous tectonic settings and demonstrate the need to seek sedimentological and stratigraphic data from deformed and dismembered parts of deep-water systems.