This information has been developed from the publications:
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Location Access Ownership | Kirk Point - 820855. Former Shire of Corio. Coastal embayment and associated wetland four km north of Point Wilson. Twenty Nine Mile Road. Crown land. | ![]() KP1 - Shelly barrier spits, Sand Hummocks. |
Site Description | The Sand Hummocks is a shallow, largely infilled tidal embayment and lagoon formed by the sea flooding a gently sloping depression on the surface of the Werribee Plains. The lagoon is partly enclosed by two long narrow barrier spits that are surmounted by beach ridges and crossed by tidal entrances of variable position and size. The inner margin of the site is defined by a low bluff that extends up to one km inland from mean high water mark. The bluff is an abandoned marine shoreline cut at the maximum limit of the Holocene marine transgression before the infilling of the embayment by sediment and salt marsh. In places the bluff is marked by an abrupt interface 30 to 40 cm high separating the embayment from the basalt plains, but elsewhere it is degraded to a sloping surface that merges with the lower salt marsh terrain. |
In front of the bluff lies a complex zoned salt marsh developed on the sand, shells and mud that have infilled the embayment. In the upper (inner) zones, the marsh includes unvegetated salt and claypans, open shrublands dominated by Halosarcia halocnemoides (Grey Glasswort), herb fields of Sarcocornia quinqueflora (Beaded Glasswort) and Frankenia pauciflora (Southern Sea-heath), and sedge lands of Gahnia filum (Chaffey Saw-edge). Seaward of this the lower marsh zones are dominated by close shrubland of Sclerostegia arbuscula (Shrubby Glass-wort). Included in this, and coinciding with a small change in the level of the marsh surface, is an arcuate zone 8 to 10 m wide without Sclerostegia dominated by a low Sarcocornia quinqueflora. The salt marsh is dissected by a well developed network of tidal drainage channels, some of which extend inland to terminate in the salt pans of the upper marsh zone. Sandy ridges enclosed in the salt marsh zones are relict spits or cheniers emplaced by wave action before the salt marsh reached its present extent. |