Toppin Hill, Lake Rason, Laverton Shire, Western Australia, Australiai

Regional Level Types
Toppin Hill	Hill
Lake Rason	Lake
Laverton Shire	Shire
Western Australia	State
Australia	Country

Guano deposit.

Toppin Hill is approximately 10 kilometres north-west of the western end of the Rason Lake saltpan. It is approximately 200 kilometres east of Laverton in the remote western Gibson Desert. It can be reached from Laverton first south-east along Merolia Road, and then east along Rason Lake Road. It is likely the last is little more than an overgrown two wheel track. No towns, stations or people of any sort exist between Laverton and the location.

The exact location of the type locality material is unclear. The species was discovered by the WA Government Chemical Laboratories in 1973, from an existing specimen labelled Struvite, in the E.S. Simpson collection. This specimen had been donated by a pastorlist and explorer, Frank Hann, who named Toppin Hill in 1906. The locality given was Earles or Earles Find, which the reference notes has not been found on any government record,and does not appear in the public domain now either. If anyone does know, then please update Mindat and you will solve a one hundred year mystery. The reference isn't forthcoming over why Toppin Hill was chosen other than its a locality they can identify with Frank Hann. Considering the vague nature of this, the separate locality of Earles Find has been left on Mindat. Phosphammite listed against this as its type locality actually refers to the same specimen as the one described for Urea under Toppin Hill.

It is thought the specimen would have come from guano in a cave or rock shelter inhabited by bats. It is highly soluable but persists at the location due to low humidity and rainfall. Urea on the specimen occurs as crystals in association with phosphammite, ammonian aphthitalite, and weddellite

The specimen was described as a damp(?) incoherent mass of pyramidal urea crystals 3 x 1mm, translucent, and pale yellow to pale brown. The ammonian aphthitalite was dark brown soft finely crystalline aggregates 1 mm in diameter, which could be shrivelled bat droppings. The phosphammite is sparse transparent crystals 0.5mm grown on the aphthitalite. Weddellite is small amounts of pale yellow crystal aggregates.

Other Regions, Features and Areas containing this locality

References