Mud Tank Vermiculite Mine, Alcoota Station, Central Desert Region, Northern Territory, Australiai

Regional Level Types
Mud Tank Vermiculite Mine	Mine
Alcoota Station	- not defined -
Central Desert Region	Region
Northern Territory	Territory
Australia	Country

Vermiculite is used as hydroponic 'soil', fire retardant, insulation, in brake linings, packing material and a variety of other products, and industrial processes. It has the ability of expanding by several times its original size upon heating. At the time of writing the Mud Tank location, is Australia's only operating vermiculite mine.

The deposit was first noted in 1944, with an open cut mine established in 1996. The mine was purchased by French company Imerys in 2002, from Imdex Ltd. The mine borders the Mud Tank Zircon Field, a well known fossicking site. Zircons are also found at the mine site, although it appears they get dumped on the spoil heap.

The Mud Tank Carbonatite occupies several lenses along a 5 kilometre section of a shear zone. A far smaller area occurs 2 kilometres to the west south-west.

The country rock is schist and gneisses of the Arunta Complex.

The rocks are banded as crystalline carbonate rocks containing apatite, magnetite, phlogopite, chlorite and soda-amphibolite; foliated micaeous carbonate rocks rich in pale-brown phlogopite; and feldspathic carbonate rocks with variable amounts of sodic-plagioclase, clinopyroxene, green-brown amphibolite, and brown biotite. Calcite and dolomite is found in all rock types, and trace niobium and other rare earth elements. Vermiculite mica is found within 40 metres of the surface.

Apatite forms massive aggregates up to 60 cms in diameter, magnetite as twinned octahedra up to 10 cms in diameter, mica as plates up to 2cms across, and zircons as relative squat prism crystals up to 5 cms long by 2 cms across.