Visit to Tanzanian spinel and corundum deposits (2010)

Tanzania

Photos © M S Krzemnicki, SSEF Swiss Gemmological Institute Movies © W Balmer

Matombo Mahenge

Umba

Arusha

Mahenge 650 580 Ma Pan African orogeny in the Mozambique Belt

Regional geology

Striking similarities to the tectonic structure of the Central Alps, Switzerland. after Escher et al

after Fritz et al , 2005 A TC WG EGC EGB GT

A´ exposure level

a) Central Mozambique Belt (ca 620 Ma) (ca 550 Ma)

GSB

Matombo (Uluguru Mountains) Morogoro Province

(Uluguru Mountains) Morogoro Province

Mwarasi ruby deposit near Matombo

The ruby mineralisation is found in zones of high permeability along fold axial hinges

Mwarasi ruby deposit

Structure controlled mineralisation :

Mwarasi ruby deposit

Visit at the spinel mines at Mahenge

Mahenge

© Swiss Gemmological Institute SSEF

Epangko spinel mines

Epangko

Umba plain

Near Kigwassi, Umba valley

Kigwassi, Umba valley

Moonlight buffet at the Mississippi Motel in Kigwassi

Ruby mine near Kigwassi (Umba valley)

Ruby mine near Kigwassi, Umba valley

High Noon in Kigwassi (Umba)