Bidaminna is hosted in the Perth Basin, in the Guildford and Yoganup Formations on the eastern margin of the Swan Coastal Plain.
The Yoganup Formation is a buried pro-graded shoreline deposit, with dunes, beach ridge and deltaic facies. This formation lies unconformably over the Lower Cretaceous Leederville Formation and is overlain by the Pleistocene Guildford Formation and Bassendean Sand.
The Yoganup Formation consists of unconsolidated poorly sorted sands and gravels, with local interstitial clay and heavy minerals that occur sporadically along the Gingin Scarp, which is interpreted to be an ancient shoreline that was stable during a period of marine regression.
The overlying Guildford Formation consists of silty and slightly sandy clay and commonly contains lenses of fine- to coarse-grained, very poorly sorted, conglomeratic and (in places) shelly sand at its base.
Two mineralised strandlines have been interpreted using a nominal cutoff grade of 1% total HM. Lower grade mineralisation is present within the sediments of the lower horizon of the Guildford Formation and within the Yoganup Formation.
Dimensions
Two mineralised strandlines have been interpreted within the resource area that have a strike length of 6.7 km. The historical Geopeko drilling indicates that the strandline mineralisation may extend to the north for an additional 2.8 km.
The upper strandline mineralisation, towards the base of the ........
