The deep-water sediments of the Tamworth group are largely graywacke rudites, graywackes, and argillites. Lithic labile graywackes predominate. Their source materials are postulated as deriving from a volcanic island are complex. The argillites usually contain radiolarians and are often calcareous, probably as a result of calcification during diagenesis. The lower Devonian Drik-Drik formation is mostly hematized keratophyric detritus, presumably deposited in shallow water within its source area. Other formations within the group show extensive evidence of being deep-water turbidites.