Manganese
Iron Ore, Bauxite and Manganese Deposits of NT Report [PDF 6.9mb]
Iron Ore, Bauxite and Manganese Deposits of NT Report [RTF 45mb]- Ferro Alloys Factsheet and Map [PDF 1.1mb]
- Ferro Alloys Factsheet and Map [DOCX 506kb]
The Northern Territory is one of the world’s largest manganese producers, with total production over 78 Mt of manganese ore. Current resources for the NT are estimated at over 200 Mt of manganese ore. There are currently two mines in operation: Groote Eylandt Mining Company (GEMCO)’s Groote Eylandt mine and the Bootu Creek mine operated by OM Holdings Ltd.
Oolitic and pisolitic ore in Mesozoic sedimentary rocks on Groote Eylandt in the Gulf of Carpentaria hosts forms one of the world's highest-grade manganese deposits of 170 Mt at 47.1% Mn. Production from Groote Eylandt in 2011 totalled 3.958 Mt of manganese ore. In 2011, GEMCO announced plans to proceed with the $280 million Phase 2 expansion of the operation, which will increase GEMCO’s beneficiated product capacity to 4.8 Mtpa.
The other operating manganese mine in the Northern Territory occurs in Palaeoproterozoic rocks of the Tennant Region at Bootu Creek 110 km north of Tennant Creek, which commenced operation in 2006. OM Manganese Ltd began mining operations at Bootu Creek in November 2005. At 31 December 2010, the total Mineral Resources were 32.5 Mt at 22.6% Mn and Ore Reserves were 21.5 Mt at 21.0% Mn. Full year production in 2011 was 902 082 t grading 36.7% manganese.
Manganese occurrences in the Northern Territory have been classified into three types: sedimentary, hydrothermal and surficial. Sedimentary Mn deposits along the western margin of the Carpentaria Basin, such as Groote Eylandt, are the most prospective target. These deposits were originally precipitated during a Cretaceous (95 Ma) marine regression on coastal terraces and troughs. Bootu Creek is an extensively modified Palaeoproterozoic (1730 Ma) sedimentary deposit in the northern Tennant Region. Sedimentary manganese deposits are also present in the Amadeus Basin (eg Wangatinya).
Surficial manganese deposits are present in the eastern McArthur Basin (eg Masterton No2) and northern Dunmarra Basin (eg McLeans). These deposits are small in tonnage, but may contain localised high-grade ore material.
