Stratigraphy and geological evolution of the Wooramel Bank, Shark Bay, Western Australia

[Truncated] The Wooramel bank is a fringing Holocene carbonate bank located in Shark Bay, Western Australia. The bank extends for 125 k m along the landward margin of a semi enclosed embayment and is confined to the north and south by two active delta systems. Bank structure is characterised by a lack of internal framework and is a product of seagrass communities trapping and binding biogenic and siliciclastic detritus. This trapping mechanism has resulted in a wedge-shaped bank up to 5 metres thick and19 kilometres wide.
Growth of the Wooramel bank over the past 10,000 years has been a dynamic interplay of sea level fluctuations, seagrass colonisation and tidal channel growth. Vertical and lateral accretion rates were related to sea floor fluctuations (cycles). The maximum period of vertical accretion (3m/1000 yr) occurred from 5400-3600 years before present (B. P.) related to a sea level still stand. In contrast, maximum lateral accretion of the Wooramel bank (5 km/1000 yr) occurred from 3600 year B.P. to present day during a broad regressive progradational phase observed in the Shark Bay region.
The Wooramel bank morphology is dominated by a gently sloping, seagrass covered bank top, with a sharp transition to the foreslope. The bank top is incised by numerous tidal-dominated channels that are oriented sub-perpendicular to the strike of the bank. Well developed binding mechanisms of the seagrass communities on the bank top restricted the sinuousity of channel development resulting in slightly sinuous channels with associated terminal fan development on the foreslope of the bank.