Mt Garnet Regional Geology
The Mount Garnet tin deposits are hosted in granite-intruded sediments with associated contact metamorphism and metasomatism.
The mineralisation including cassiterite, magnetite and fluorite, is contained within tabular skarn lenses that formed within carbonate-rich sediments.
The Silurian Chillagoe Formation, characterised by limestone – marble, chert, basic volcanics and siliciclastics, lies along the western margin of the Hodgkinson Province. Limestones of this formation are favourable hosts for skarn-associated tin mineralisation at Mount Garnet.
Gillian Geology
The Gillian tin deposit occurs as skarn lenses developed in altered limestone beds of the Chillagoe Formation which has been intruded by granites. The lenses are tin-iron skarns consisting of massive magnetite and goethite with fine grained cassiterite, the most common tin bearing mineral.
The deposit strikes north-south and has the dimensions 850 m north-south, 880 m east-west and 250 m vertically. In the western part of the deposit, mineralisation occurs as a number of steeply ipping tabular lenses, while mineralisation in the eastern part occurs, primarily, as a single lens.
Pinnacles Geology
The Pinnacles tin deposit occurs as a series of irregular skarn lenses developed in altered limestone beds of the Chillagoe Formation which has been intruded by granites. The deposit is a tin-fluorine-iron skarn consisting of t ........
