Help mindat.org|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportAdd Glossary Item
StatisticsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Mt Bischoff mine, Waratah, Waratah district, Tasmania, Australia

This page is currently not sponsored. Click here to sponsor this page.
 
 
The Mt Bischoff mine was discovered by farmer and part-time prospector James “Philosopher” Smith in 1871, and for many years was one of the world’s richest tin mines (Groves et al., 1972). After 70 years of continuous production, the Mt Bischoff mine finally closed in 1947. Following mining ventures have mostly been small and spasmodic. Open-cut mining restarted in 2008, with a large open pit swallowing most of the old workings, except the Slaughteryard Face. Mining reserve estimates as at June 30, 2008 are 845,000t at 1.20% Sn. The ore was trucked some 50km to the mill at the Renison Bell tin mine. Mining finished in 2011 and the pit is now flooded, but exploration continues around the pit and deeper reserves are of great exploration interest.

Mt Bischoff was the first major mineral resource developed in Tasmania, with a total production of around 62,000t of metallic tin. The discovery provided the impetus for exploration of other areas of the west coast and the subsequent discovery of other mining areas such as Mt Lyell and Renison.

Geology
Precambrian quartzite, shale and dolomite at Mt Bischoff have been intruded by a radial group of Devonian quartz-feldspar porphyry dykes and breccia dykes, related to the nearby Meredith granite. Tin-base metal sulphide mineralisation accompanies these dykes, and occurs as a replacement of dolomite, as greisenised dykes, and as veins and fracture linings (Groves et al., 1972; Wright & Kwak, 1989, Halley & Walshe, 1995; Sorrell, 1997). Tin mineralisation occurs within a radius of about 1km from the summit of Mt Bischoff, and several silver-lead-antimony deposits surround the mine. Supergene zones were minor.

Dolomite-Replacement Mineralisation
Dolomite-replacement mineralogy is dominated by sulphides (mostly pyrrhotite), Fe-Mg-Mn carbonates, fluorides (fluorite, sellaite), tourmalines and magnesium silicates (chondrodite, norbergite, clinohumite, phlogopite, talc and serpentine), in part as magnesian skarns and “wrigglite” (banded skarn), largely retrogressed. The highest tin grades were found within a quartz-pyrrhotite-topaz-fluorite assemblage (the most strongly altered dolomite replacement rocks) adjacent to the dykes, (now largely worked out). Dolomite-replacement mineralisation is found at the Greisen Face, where talc-pyrrhotite alteration occurs, and at the Slaughteryard Face, where quartz-pyrrhotite alteration and fluorite “nodules” occur.

Dyke Mineralisation
Greisenised dyke rocks are characterised by a white, fine-grained groundmass of quartz and topaz, with orthoclase phenocrysts variably pseudomorphed by siderite, pyrrhotite, quartz, topaz, pyrite, fluorite and cassiterite. One of the most prominent features of Mt Bischoff is the Western Dyke, a greisenised porphyry with cassiterite both disseminated and coating joint surfaces.

Veins and Fracture Linings
Fissure lodes are a late phase of mineralisation, cross-cutting dykes and country rocks. They contain variable proportions of quartz, siderite, tourmaline, topaz, fluorite, cassiterite, wolframite and sulphides (pyrite, pyrrhotite, galena, sphalerite, chalcopyrite, bismuthinite, As-Sb-Bi sulphosalts and stannite).

More than 100 mineral species have been recorded from Mt Bischoff, particularly because of the extensive alteration and large amounts of magnesium and fluorine in the system, producing both attractive and uncommon minerals such as sellaite, franckeite, chondrodite, norbergite, wagnerite and fluoborite.

Mineral List

Mineral list contains entries from the region specified including sub-localities


151 entries listed. 122 valid minerals.

Localities in this Region

Australia

The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

- McAndrew, JA, 1965, Geology of Australian ore deposits. AIMM.
- Anon, 1970. Catalogue of the Minerals in Tasmania. Geol. Surv. Record No. 9, Tasmania Department of Mines.
- Groves, D.I., Martin, E.L., Murchie, H., & Wellington, H.K., 1972. A Century of Tin Mining at Mount Bischoff, 1871-1971. Geological Survey Bulletin No. 54. Tasmanian Department of Mines.
- Wright, J.H. and Kwak, T.A.P., 1988. Endogreisen, brecciation and fluid activity at the Mount Bischoff Sn-deposit, North-west Tasmania, Australia. Journal of Metamorphic Geology 6, 629-650.
- Econ Geol (1989) 84:551-574
- Burrett, C.F. & Martin, E.L., eds., 1989. Geology and Mineral Resources of Tasmania., p. 383-398. Geological Society of Australia Inc., Special Publication 15.
- Rocks & Min.: 22:326.
- Dickens, G., 1995. Mining in Tasmania – a brief History. Tasmanian Geological Survey Record 1995/11.
- Halley, S. & Walshe, J.L., 1995, A re-examination of the Mt Bischoff cassiterite sulphide skarn, Western Tasmania. Economic Geology, 90, 1076-1683.
- Sorrell, S, 1997. Mt Bischoff – Mountain of Tin. Mineralogical Society of Tasmania, Newsletter, 20, 7-16.
- Bottrill, R.S. and Baker, W.E., 2008. Catalogue of Minerals of Tasmania. Mineral Resources Tasmania.



External Links


Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2015, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: July 1, 2015 18:04:16 Page generated: July 1, 2015 13:39:26