Angas Geology and Mineralisation

The Angas Zinc Mine lies within a belt of mostly siliciclastic marine sediments of Cambrian age, known as the Kanmantoo Trough.   Angas mineralisation lies within the Tapanappa Formation.  At the mine site the Tapanappa Formation is composed of a monotonous sequence of flysch style interbedded metapsammite and metapelite.   The sequence has been regionally metamorphosed to amphibolite facies.  The Angas mineralisation lies within the "Host Unit" which is defined by the presence of minor (1-2%) to common fine grained garnet, believed to be of hydrothermal origin, which varies from about 50m to 200m in thickness and occurs as a continuous planar body discordant to stratigraphy, over a strike length of at least 2km and a dip extent of more than 500m.

A number of isoclinal folds have been recognised in the hanging wall and there is a strong axial plane schistosity which for the most part is sub-parallel to bedding.  Extensive shearing is associated with the mineralisation and in the footwall and hanging wall. 

Economic mineralisation at Angas is contained within the garnetiferous "Host Unit" and extends approximately 700m along strike and 500m down dip.  The width varies between less than 0.5m to 20m.  Sphalerite, galena and chalcopyrite are associated with variable concentrations of pyrite and pyrrhotite.  Abundant pyrrhotite is also commonly observed along strike of base metal mineralisation.

The ore occurs in three north-south oriented zones of mineralisation.  The largest is Rankine with the smaller but higher grade Garwood along strike to the south.  The Hanging Wall Zone lies in the hanging wall of Rankine.  The orebody is shallow with the Rankine zone outcropping.

Regional Location

Terramin exploration licences are given in red

Location map - click to enlarge the image

Cross Section at 7225N

Cross Section of Angas at 7225N- click to enlarge the image