“The origin of the Mitchell River silt jetties has been the subject of some debate and sever hypotheses have been advance to account for the unusually large deltaic tract of a relatively small river. It seem likely that the silt jetties are a true deltaic form consisting of silt, clay and minor sands and are comparable in configuration with those built by distributaries of the Mississippi River into the Gulf of Mexico. The major factors in their growth were the virtual absence of tidal currents in Lake King and the presence of a shoreline reed swamp fringe able to trap a large proportion of the river sediment and affording protection from wave attack. The elongated digitate form of the Mitchell silt jetties compared with the smaller cuspate deltas of the other river is a reflection of the fact that the north-western part of the other rivers is well sheltered from both westerly and easterly winds.” (1)
1 – http://vro.agriculture.vic.gov.au/dpi/vro/egregn.nsf/pages/eg_lf_sites_significance_gl19