ABSTRACT

A coastal cliff outcrop section, up to 200 m thick and 4 km long, through the upper part of the Late Miocene Mt. Messenger Formation, Taranaki, New Zealand, consists mainly of well-sorted, very fine- to fine-grained, thin-bedded sandstone and siltstone. The strata form a series of 4th-order cycles within an overall 3rd-order fall-rise cycle, which were deposited at mid- to upper-bathyal water depths at a time of high sediment supply. Lithofacies are dominated by turbidite beds, particularly horizontally-bedded (Tb) and climbing ripple-laminated (Tc) sandstones, with siltstones (Te).

The section displays abundant erosional cut-out of beds by scours, slumps, or channels. In many cases the scours are lined with mud indicating that a considerable time elapsed between their incision and subsequent filling. Erosional cut-out limits lateral bed continuity. At a smaller scale, bed continuity is also interrupted by bioturbation, particularly by Scolicia burrows. We interpret the outcrop section as a series of stacked slope fans (channel-levee complex). This section is thought to closely resemble many of the sedimentologic and stratigraphic attributes of reservoirs in the Gulf of Mexico and elsewhere.