Basil Prospect, Harding Springs, Ambalindum Station, Harts Range (Harts Ranges; Hartz Range; Hartz Ranges), Central Desert Region, Northern Territory, Australiai

Regional Level Types
Basil Prospect	Prospect
Harding Springs	Group of Springs
Ambalindum Station	- not defined -
Harts Range (Harts Ranges; Hartz Range; Hartz Ranges)	Mountain Range
Central Desert Region	Region
Northern Territory	Territory
Australia	Country

This deposit was discovered in 2009. Sharrad (2012) indicates that the formation of the deposit is poorly understood due to deformation and metamorphic overprinting. Suggested as a Volcanogenic Massive Sulphide (VMS) style deposit.

The deposit is hosted by the Riddoch Amphibolite, consisting of Fe rich metapelite-mafic gneiss, marble, calc-silicate rocks, and metabasic rocks. Mineralisation is found along a 10 kilometre length at the surface, along the Basil Fault structural corridor. Exploration has taken place in a couple of main zones 10-20 metres thick at a place with the unpromising name of Rotten Hill, at the far south-east extent of the Harts Range.

There are four main units (1) amphibolite (2) garnet rich amphibolite (3) epidote amphibolite schist (4) weakly foliated amphibolite. Gangue includes magnesiohornblende, andesine, quartz, garnet, hematite, ilmenite, and magnetite, suspended in a sulphide matrix. Each garnet is composed of almandine (60%), pyrope (30%), and grossular (10%), with very minor spessartine on average. The garnet rims are enriched with Heavy Rare Earths.

Sulphides are up to 60% volume of the rock, mainly pyrite and pyrrhotite, and relatively minor chalcopyrite, and sphalerite, all disseminated in the host rock. Chalcopyrite and sphalerite is associated with pyrite, and pyrrhotite, or as small blobs.

The amphibolite consists of brown-green magnesiohornblende (40%), andesine (25%), quartz (10%), pervasive titanite (10%), ilmenite (10%), zircon (3%), apatite (2%), rutile (1%), minor pyrite, pyrrhotite, garnet.

The garnet rich amphibolite consists of garnet with sulphide inclusions, or surrounded by a sulphide matrix (almandine 60%), green magnesiohornblende (20%), ilmenite (10%), apatite (2%), chlorite (1%).

The epidote amphibolite schist consists of brown-green magnesiohornblende (25%), epidote (25%), andesine (15%), orthopyroxene (15%), quartz (10%),
pervasive titanite (10%), scapolite (2%), dolomitic carbonate (2%), calcite (1%), and abundant zircon.

The weakly foliated amphibolite consists of brown magnesiohornblende (40%), clinopyroxene (20%), andesine (20%), quartz (10%), abundant titanite (10%). There is also carbonate/chlorite alteration of chlorite (60%), calcite (30%), fine grained and abundant magnetite (10%).

Other Regions, Features and Areas containing this locality

References