Mud Tank Zircon Field, Alcoota Station, Central Desert Region, Northern Territory, Australiai

Regional Level Types
Mud Tank Zircon Field	Complex
Alcoota Station	- not defined -
Central Desert Region	Region
Northern Territory	Territory
Australia	Country

The Mud Tank collecting area is 6 km from Plenty Highway. This is a popular collecting spot, mostly for large zircon crystals, in a carbonatite. The Mud Tank carbonatite comprises at least four pipe-like bodies tending in a northeast-southwest direction. The outcrops form a series of low hills spread over 5km of which the most northerly is the most prominent. The most northerly was being mined for vermiculite recently, with collectors allowed to fossick on the dumps still.

Mud Tank is listed in many publications as Harts Range or Harts Range district but is in fact in the far eastern end of the Strangways Range, located on Alcoota Station.

It should be noted that many refer to the Strangway Ranges but the Geoscience Australian and the Northern Territory Government lists it as Strangways Range - see for example "Strangways Range region NT 1:100 000 geol map commentary - Sheets 5651/5751.

The zircon field is 7.7 kilometres east from the Gemtree caravan park, turn south at the Mud Tank Bore and head 6 kilometres south-west. Most zircons found are orange to amber to pale brown, but also to a lesser extent pink, purplish, colourless, yellow, part-coloured, as double terminated small crystals, and chips. There are two closely spaced locations being Specimen Hill, and Mud Tank Hill. The former contains larger zircon crystals, but are often internally flawed. Some smaller crystals can be cutting quality. Waterworn crystals can be found in low lying areas between the two locations. Zircons are found by digging down to the gravelly wash layer, containing zircons, apatite nodules, mica chips, and rubble. At the western side the wash layer is virtually at the surface, while the eastern side it is about one metre below the surface.

Apatite is found as big, fractured, pale green or brown lumps. Magnetite blackish, and has generally oxidised to martite, a metallic lustre, and non magnetic. Zircon crystals may be found within the magnetite. Pink microcline and small garnets occur on the western side of the main diggings. Moonstone can be found on a low hill between Specimen Hill and the main diggings. Vermiculite as a golden soft flaky mica is common.

As some people camp on the field the entire winter, the amount of zircons available has gradually decreased over the decades, although a day of hard work is still guaranteed of producing a small handful of specimens. Fossicking tours to the site is conducted by the Gemtree caravan park, which can also arrange the cutting of suitable stones for a fee.

Geochronology

Mineralization age: Neoproterozoic : 732 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic Time				Rocks, Minerals and Events
Precambrian
	Proterozoic
		Neoproterozoic
			Tonian	ⓘ Zircon 732 Ma

Other Regions, Features and Areas containing this locality

References