Murra-El-Elevyn Cave, Cocklebiddy Roadhouse, Dundas Shire, Western Australia, Australiai

Regional Level Types
Murra-El-Elevyn Cave	Cave
Cocklebiddy Roadhouse	Community
Dundas Shire	Shire
Western Australia	State
Australia	Country

Type locality for bisphosphammite, and a number of bat guano related species.

Located about 5 kilometres west of the Cocklebiddy Roadhouse and 1 kilometre south of the Eyre Highway. A permit is required to enter the cave, although there appears no obvious easy access from the sinkhole.

A sinkhole with a 300-metre long main tunnel, and two interconnected networks, one half filled with water and the other completely filled.

The breakdown of bat droppings and urine to form nitrogen has interacted with the phosphate, potassium, and calcium of the limestone to form a suite of unusual species. The cave is the roosting place of Chalinolobus morio (chocolate wattled bat). They have created a large guano pile coating the limestone with a buff to dark brown-black massive to crystalline crust with insect remains, bat droppings, dead bats, and skeletal material in an atmosphere of 88% humidity (have we put you off becoming a geologist yet?!)

The massive portion of the crust is an intergrown mixture of aphthitalite, syngenite, monetite, whitlockite, gypsum, and organic material. The crystalline coatings are biphosphammite, ammonian KH2PO4 which is described as visually identical to bisphosphammite but yet to be studied, occurring as buff to white 2.0 x 0.2 mm tapering prisms. Hannayite is found as occasional clear pale brown platy 0.2 x 0.5 mm crystals in groups coating the crusts. Brushite and taylorite as scattered or grouped white feathery 0.25 x 0.20 mm crystals. Mirabilite as small clear crystal groups with organic fibres on steep slopes near the guano pile, but not associated with the crust. Carbonate-rich Hydroxylapatite ("Dahllite") as dark brown, smooth coatings on the higher ledges where the bats once roosted.

Other Regions, Features and Areas containing this locality

References