Late Palaeozoic rocks of the New England Fold Belt in eastern Australia preserve from west to east: a continental volcanic chain, a forearc basin and a subduction complex. The Gundahl Complex and the Coffs Harbour sequence are two tectono-stratigraphic units in the subduction complex that consist of contrasting trench-floor sedimentary sequences. The Gundahl Complex is a tectonic melange containing slabs and blocks of greywacke, greywacke-argillite, argillite, argillite-tuff, bedded chert and greenstone. Some slabs have representative sections of the pre-melange stratigraphic sequence that resemble trench-floor deposits. Other slabs have thick sequences of argillite and argillite-tuff and are probably trench-slope basins kneaded into the subduction complex. The Coffs Harbour sequence is a faulted-folded assemblage of turbidites. The structural style, regional extent and near strike-parallel sediment movement directions suggest it was probably deposited in a trench. Probable environments of turbidite deposition are starved trench, non-channelized trench and outer-fan submarine settings. The facies differences between the two units reflect slower subduction rates and higher sedimentation rates for the Coffs Harbour sequence. �� 1985.