Late Miocene marine fossil-rich, rock-fall, avalanche, mud-flow and debris-flow deposits adjoining and near the western margin of the Tawhero Basin, outer forearc North Island, New Zealand

A late Miocene marine, massive fossil-rich, rock-fall/avalanche deposit, >4 2 m thick (base unexposed) and mud-flow and debris-flow deposits, commonly 0.2-4 m thick, are present adjoining and near to either margin of a 12 km l ong segment of the NE-trending Waihoki Fault/fault zone, near Pongaroa, Nor th Wairarapa, North Island, New Zealand. The Waihoki Fault/fault zone lies in the outboard part of the onland part of the forearc. It forms the wester n margin of the Tawhero Basin, a forearc basin overlying a subducting Pacif ic plate, during 6.6-25 Ma. The basin had a partly dextral transpression hi story (especially in the Late Miocene) but the amount of dextral displaceme nt along the Waihoki Fault/fault zone is unknown. It is likely that lightly indurated fossil-rich, rock-fall, mud-flow and debris-flow deposits were d erived from the tops of fault slivers that were pushed upwards along the Wa ihoki Fault/fault zone during dextral faulting to reach the neritic zone.