Maroota Sands deposits are a distinct geological formation which are the remains of two river systems which were deposited during the Tertiary period. Materials laid down in these deposits include sands, clays and gravels. The deposits have been quarried for many years to supply building materials for the Sydney market. Indigenous inhabitants of the area used the rock types such as quartz, jasper, agate and chert within the deposits in the manufacture of flaked stone tools, spear barbs and scrapers [article by Tessa Corkill, archaelologist].