Hillgrove, Sandon Co., New South Wales, Australia

A sediment hosted syn-orogenic lode gold deposit also known as a shallow mesothermal deposit(AuSb +/-WoAg sub-type). The area near Hillgrove has over 200 old mines and workings centred on NW-NNW trending faults and shears; although some of the larger structures trend E-W. The lodes are mostly hosted in a 2 x 5km block of meta-sedimentary rocks of the Anaiwan terrane; although some granite hosted structures occur in the north of the field. The field has mainly been worked for its gold and antimony contents although most lodes contain some tungsten the mining of tungsten has been restricted to a few minor lodes in the NW of the field; generally during times of war. Most of the gold is held cryptically in pyrite and arsenopyrite with typical grades of 2-7ppm but local enrichment sometimes exceeded 200ppm. The deposits were first discovered in 1887 and mining commenced several years later, the area was almost continously mined up until 2001.

References:
- Ashley, P.M., Cook, N.D.J., Hill, R.L. (1990): Occurrence and significance of aurosibite in the Au-Sb ore from Hillgrove, New South Wales, Australia. Neues Jahrbuch für Mineralogie 12, 539-551.
- Ashley, P.M., Creagh, C.J., and Ryan, C.G. (2000): Invisible gold in ore and mineral concentrates from the Hillgrove gold-antimony deposits, NSW, Australia. Mineralium Deposita 35, 285-301.