Simberi Island

Simberi
Satellite image of Simberi Island
As seen from Landsat
Simberi is located in Papua New Guinea
Simberi
Simberi
Geography
LocationMelanesia
Coordinates2°37′29.33″S 151°58′25.96″E / 2.6248139°S 151.9738778°E / -2.6248139; 151.9738778
ArchipelagoBismarck Archipelago
Area40 km2 (15 sq mi)
Highest elevation340 m (1120 ft)
Administration
ProvinceNew Ireland Province
Demographics
Population1100[1]

Simberi Island is a volcanic island in the Tabar Group, in Papua New Guinea's New Ireland Province.[1]

Geography and geology

Simberi is the northernmost and smallest of the three islands in the Tabar Group. The island is about 9 km (5.6 mi) long and 7 km (4.3 mi) wide and has an area of about 40 square kilometers (15 sq mi). Its highest point in the highlands on the eastern side of the island is a 340 m (1,120 ft) eroded volcanic cone. The interior of the island is largely covered by rainforest. Most of the island's coast is steep and surrounded by a fringing reef together with a series of small islets. There is a woman shaped figure made by trees on the island and a barrier reef about 10 km (6 mi) offshore from the west coast. A 2 km (1 mi) strait separates Simberi from Tatau Island to the south west.

Simberi island is a potassium rich (high-K) calc-alkaline island arc volcano, the oldest in the Pliocene to Holocene Tabar-Lihir-Tanga-Feni (TLTF) volcanic arc that formed above a subduction zone.[2][3]

People

The population is about 1100 and made up of nine clans who live in small coastal villages mainly in the north and west.[1] The local language is a Simberi dialect of Mandara (also known as Tabar), ISO 639-3 language code "tbf", an Austronesian language spoken on the Tabar Islands.[4][5]

Transport

The island has an airport, Simberi Airport (IATA airport code "NIS"), on the south east coast.[6]

Simberi Oxide Gold Project

Main article: Simberi mine

St Barbara Limited, an Australian-based company, operate an open pit gold (and silver) mine called the Simberi Oxide Gold Project in the volcanic highlands on the eastern side of the island.[1] The mine is wholly owned and operated by St Barbara Limited, who acquired the assets of Allied Gold, the previous operators of the Simberi mine, on 31 August 2012.[1] Gold production started in February 2008.[1] Mining was suspended in December 2009 after Allied Gold received a cease work order from the Mineral Resources Authority of Papua New Guinea because of local landholder issues.[1] Mining has since recommenced.[1]

Seven gold deposits have been defined in mining lease 136 (ML 136), which covers the central and eastern portion of Simberi Island, and other prospects have been identified.[1][6] The gold deposits occur mainly on ridge tops and are all within 2–3 km (1–2 mi) of each other.[1][6] Sorowar in the north is the largest resource while Samat North, South and East to the south are relatively small but relatively high grade.[6] Pigiput, Pigibo and Botlu South lie between the Sorowar and Samat areas and are of intermediate tonnage but at a grade similar to Sorowar.[6] The western area of Simberi Island within exploration license EL 609 is largely unexplored.[7] Reconnaissance exploration for both oxide and sulphide mineralisation is planned.[7]

As of June 2009, Allied reported that the total resources were 4.7 million troy ounces (5.2 million ounces; 150 million grams) (Moz) gold, being oxide gold resources of 1.4 million ozt (1.5 million oz; 44 million g) and sulphide gold resources of 4.7 million ozt (5.2 million oz; 150 million g) together with 10.2 million ozt (11.2 million oz; 320 million g) silver.[6]

Ore is delivered to the processing facilities on the eastern coast near Pigiput Bay by a 2,665 m-long (8,743 ft) RopeCon aerial conveyor that can deliver 600 tonnes (590 long tons; 660 short tons) of ore per hour.[1][8] The process plant is a conventional carbon-in-leach (CIL) gold process plant capable of treating 2.2 million tonnes (2.2 million long tons; 2.4 million short tons) of ore per year.[6] In September 2010, Allied announced that it planned to increase its gold production to 100,000 troy ounces (110,000 oz; 3,100,000 g) per year.[7] The oxide processing circuit at the Simberi operation will be expanded to 3.5 million tonnes (3.4 million long tons; 3.9 million short tons) a year, by June 2013.[9]

Mine tailings are disposed of in the form of a slurry that has been pre-diluted with seawater using a deep sea tailings pipeline.[1] The pipeline is 528 m (1,732 ft) long with the discharge point at a depth of 130 m (430 ft). The tailings flow down a steep submarine slope and are deposited at a depth of more than 3 kilometers (1.9 mi).[6]

Production for the period from 1 July 2009 to 30 June 2010 was 64,327 troy ounces (70,576 oz; 2,000,800 g).[10]

In June 2009, Allied reported that the remaining mine life was estimated to be over 10 years.[6] St Barbara Limited (Australia) acquired Allied in September 2012 and is the current owner of this mining operation.[11] They are the largest employer on the island.[6]

References

  1. ^ a b c d e f g h i j k l "Simberi". Mineral Policy Institute. Archived from the original on 16 February 2011. Retrieved 9 September 2010.
  2. ^ McInnes, Brent I.A.; Eion M. Cameron (March 1994). "Carbonated, alkaline hybridizing melts from a sub-arc environment: Mantle wedge samples from the Tabar-Lihir-Tanga-Feni arc, Papua New Guinea". Earth and Planetary Science Letters. 122 (1–2). Elsevier B.V.: 125–141. Bibcode:1994E&PSL.122..125M. doi:10.1016/0012-821X(94)90055-8.
  3. ^ McInnes, Brent I.A. (1992). A glimpse of ephemeral subduction zone processes from Simberi Island, Papua New Guinea. Thesis (Ph.D.). University of Ottawa (Canada).
  4. ^ Lewis, M. Paul (ed.). "Ethnologue: Languages of the World – Mandara". SIL International. Retrieved 17 September 2010.
  5. ^ Brown, Keith, ed. (2006). Encyclopedia of Language & Linguistics. Elsevier. p. i. ISBN 978-0-08-044854-1.
  6. ^ a b c d e f g h i j "Allied Gold Annual Report 2009" (PDF). Allied Gold. Archived from the original (PDF) on 17 February 2011. Retrieved 10 September 2010.
  7. ^ a b c Swanepoel, Esmarie (2010-09-15). "Allied Gold approves $32m gold expansion at PNG mine". Mining Weekly. Retrieved 15 September 2010.
  8. ^ "RPC RopeCon Simberi". Doppelmayr. Retrieved 16 September 2010.
  9. ^ "Pacific Operations FY13 Guidance" (PDF). SBM. Retrieved 20 December 2012.
  10. ^ "APPENDIX 4E: PRELIMINARY FINAL REPORT 2010" (PDF). Allied Gold. 2010-06-30. Archived from the original (PDF) on 17 February 2011. Retrieved 15 September 2010.
  11. ^ "Simberi". St Barbara Limited.