Episodic post‐glacial sea‐level rise and the sedimentary evolution of a tropical continental embayment (Cleveland Bay, Great Barrier Reef shelf, Australia)

Abstract

Cleveland Bay is a 400 km2 landlocked tropical embayment located at 19° S and 146° 55´E The bay is protected from the dominant southeasterly tradewind by Cape Cleveland, but lies open to northerly and northeasterly weather and to the effects of occasional tropical cyclones. Water‐motion within the bay is dominated by the effects of refracted southeasterly‐generated waves (mostly 0.5–1.2 m high, 4–6 s period) and by semi‐diurnal tidal currents, which reach speeds of 15–30 cm/s during spring tides. Residual circulation within the bay is anticlockwise and results in preferential sediment accumulation on the eastern side. The bay contains three main Holocene stratigraphic units (A‐C) which rest on weathered Late Pleistocene clay. The Pleistocene land surface is planar, dips seawards at 0.8 m/km and is incised by a major complex of fluvial and tidal channels. Seismic unit C encompasses cross‐bedded or draped fill of the channel system. Seismic unit B, occurring laterally to C, comprises massive grey mud with m...