Tsumeb

Tsumeb
St. Barbara Church - Tsumeb
Seal
Motto: Glück Auf (German mining term for Good luck!)
Satellite view
Tsumeb Location in Namibia
Coordinates: 19°15′S 17°52′E / 19.25°S 17.867°E / -19.25; 17.867
Country	Namibia
Region	Oshikoto Region
Time zone	South African Standard Time (UTC+1)

Tsumeb is a city^[1] and the the largest town in Oshikoto region in northern Namibia. Tsumeb is the "gateway to the north" of Namibia^{[citation needed]}. It is the closest town to the Etosha National Park, and has a population of 20,000 inhabitants.

The town and the old mine

Main road in Tsumeb

Tsumeb open cast pit, buildings and railway about 1931

The name Tsumeb is generally pronounced "SOO-meb". The name is not a derivative of German, Afrikaans, or English. It has been suggested that it comes from Nama and means either "Place of the moss" or "Place of the frog". Perhaps this old name had something to do with the huge natural hill of green, oxidized copper ore that existed there before it was destroyed by mining.

The town was founded in 1905 by the German colonial power and celebrated its 100th year of existence in 2005.

Tsumeb is notable for the huge mineralized pipe that led to its foundation. The origin of the pipe has been hotly debated. The pipe penetrates more or less vertically through the Precambrian Otavi dolomite for at least 1300 m. One possibility is that the pipe was actually a gigantic ancient cave system and that the rock filling it is sand that seeped in from above. If the pipe is volcanic, as some have suggested, then the rock filling it (the "pseudo-aplite") is peculiar in the extreme. The pipe was mined in prehistoric times but those ancient workers barely scratched the surface. Most of the ore was removed in the 20th century by cut-and-fill methods. The ore was polymetallic and from it copper, lead, silver, gold, arsenic and germanium were won. There was also a fair amount of zinc present but the recovery of this metal was always difficult for technical reasons. The pipe was famous for its richness. Many millions of tonnes of ore of spectacular grade were removed. A good percentage of the ore (called "direct smelting ore") was so rich that it was sent straight to the smelter situated near the town without first having to be processed through the mineral enrichment plant. The Tsumeb mine is also renowned amongst mineral collectors. Between 1905 and 1996, the mine produced about 30 million tons of ore yielding 1.7 Mt copper, 2.8 Mt lead 0.9 Mt zinc, as well as 80 t germanium.^[2] The average ore grade was 10% Pb, 4.3% Cu, 3.5% Zn, 100 ppm Ag, 50 ppm Ge.^[3]

It is noted for 243 valid minerals and is the type location for 56 types of mineral. Some of the germanium minerals are only found in this mine.

Tsumeb, since its founding, has been primarily a mining town. The mine was originally owned by the OMEG (Otavi Minen- und Eisenbahn-Gesellschaft) and later by TCL (Tsumeb Corporation Limited) before its closure a few years ago, when the ore at depth ran out. The main shafts became flooded by ground water over a kilometre deep and the water was collected and pumped as far as the capital, Windhoek. The mine has since been opened up again by a group of local entrepreneurs ("Ongopolo Mining"). A fair amount of oxidized ore remains to be recovered in the old upper levels of the mine. It is highly unlikely, though, that the deepest levels will ever be reopened.

The other notable feature of the town is the metal smelter, also owned by Ongopolo Mining.

Sinkhole lakes and the world's biggest meteorite

Lake Otjikoto

Near to the town are two large and famous sinkhole lakes, Lake Otjikoto and Lake Guinas ("Gwee-nus"). Guinas, at about 500 m in diameter, is somewhat larger in area than Otjikoto. A pioneering documentary movie about scuba diving in these lakes was made by Graham Ferreira in the early 1970s. The depths of the lakes are unknown, because towards the bottom both lakes disappear into lateral cave systems, so it is not possible to use a weight to sound them. Otjikoto, which has poor visibility (owing to pollution from agricultural fertilizers used nearby), is at least 60 m deep. The water in Guinas is completely clear and well over 100 m deep. Divers who have performed bounce-dives in Guinas to 80 m (strictly speaking, beyond the safe depth for SCUBA dives, especially given the altitude of the lake above sealevel) have reported that there was nothing but powdery-blue water below them. Guinas has been in existence for so long that a unique species of fish, Tilapia guinasana, has evolved in its waters.

When South Africa invaded German Southwest Africa, today's Namibia, in 1914, the retreating German forces eventually threw all of their weaponry and supplies into the deep waters of Otjikoto. Some of the material has been recovered for display in museums.

One of the largest and deepest underground lakes in the world lies a little to the east of Tsumeb, on a farm called Harasib. To reach the water in the cave one has either to abseil or to descend an ancient, hand-forged ladder that hangs free of the vertical dolomite walls of the cave for over 50 m. Here, too, SCUBA divers have descended as deep as they have dared (80 m) in the crystal-clear waters and have reported nothing but deep blue below them from one ledge of dolomite to the next with nothing discernible in the depths.

The largest meteorite in the world, called Hoba, lies in a field about forty minutes drive to the east of Tsumeb, at Hoba west. It is a nickel-iron meteorite of about 60 tonnes.

Transport

Otavi Mining and Railway Company train near Tsumeb about 1931. The photograph must have been taken in winter, as the trees have no leaves. Despite the fact that Tsumeb is in the tropics, it is well over a thousand metres above sea level and frosty in winter.

Tsumeb is connected to the national railway network operated by TransNamib. Tsumeb was for most of the 20th century the terminus of the line but in recent times the track has been extended a further 260 km to reach Ondangwa. There have been talks of extending the line to Oshikango and having the Government of Angola build a railroad from the north to connect the two countries together.

The junction for the Ondangwa line is located at the wrong end of Tsumeb railway station, leaving it a dead end, though a second triangle is provided for through trains to bypass the station.

Roads

There are main roads leading north, Ondangwa through to Oshakati and Angola, east, Grootfontein through to Rundu and Katima Mulilo, and south, Otavi through to Otjiwarongo and Windhoek.

Industry

In 2008, a cement works was planned. ^[4]

Town twinning

• Chesterfield, UK

Minerals of Tsumeb

Tsumeb belongs to the world's most prolific mineralogical sites, famous especially thanks to both beautiful and rare secondary minerals of Pb, Cu, Zn, As, Sb and, what is characteristic and reflects the ore chemistry, Ge, Ga and Cd. Minerals first described from Tsumeb include, according to MINDAT, rare (but also few common) arsenates (andyrobertsite, arsenbrackebuschite, arsendescloizite, arsentsumebite, biehlite, calcioandyrobertsite, chudobaite, duftite, ekatite, fahleite, feinglosite, ferrilotharmeyerite, gaitite, gebhardite, gerdtremmelite, helmutwinklerite, jamesite, johillerite, keyite, koritnigite, leiteite, ludlockite, lukrahnite, molybdofornacite, o'danielite, prosperite, reinerite, schneiderhöhnite, schultenite, sewardite, stranskiite, thometzekite, tsumcorite, warikahnite, wilhelmkleinite, zincgartrellite and zincroselite), unique germanium (bartelkeite, calvertite, eyselite, fleischerite, germanite, itoite, krieselite (germanate topaz), mathewrogersite, otjisumeite, ovamboite, schaurteite and stottite) and gallium (gallobeudantite, söhngeite, tsumgallite); others are: kegelite, minrecordite, otavite, plumbotsumite, queitite, sidpietersite (unique thiosulphate), stibioclaudetite, tsumebite and zincrosasite ^[5][6]<Webmineral</ref>

References

External links

• Official Tsumeb Website
• Mindat mineral location information

Coordinates: 19°15′S 17°42′E / 19.25°S 17.7°E / -19.25; 17.7