We are excited to invite you to the next seminar of the 2025 Geology and Geophysics Seminar Series, featuring Ioan Sanislav, who is an A/Prof of Economic Geology and the head of the Economic Geology Research Centre (EGRU) at James Cook University. Ioan will be presenting on “Archean gold mineralization in Tanzania – linking tectonics, magmatism and ore deposit formation“. In this engaging talk, he will present how tectonics, magmatism, and structural controls influenced gold mineralization in the Geita Greenstone Belt, Tanzania, drawing on field and geochemical studies from major deposits such as Geita, Bulyanhulu, Golden Pride, North Mara, and Tulawaka.
Date: October 29, 2025
Time: 11:00 a.m. – 12:00 p.m., Sydney Time
Location: Room 449 (Conference Room), Madsen Building (F09), School of Geosciences
or Online (Join via zoom)
We look forward to seeing you there in person or joining us online!
https://uni-sydney.zoom.us/j/82496088821?from=addon
Archean gold mineralization in Tanzania – linking tectonics, magmatism and ore deposit formation
Abstract
The formation of mineral deposits is a complex process and although most deposits occur at specific structural traps and form during punctuated hydrothermal events their genesis cannot be separated from the overall tectonic, magmatic and structural evolution of the host terrane. In this presentation I will discuss the link between tectonism, magmatism and gold deposit formation with examples from Geita Greenstone Belt, Tanzania. Tanzania Craton host numerous world class gold deposits including Geita, Bulyanhulu, Golden Pride, North Mara and Tulawaka. Despite its rich mineral endowment, Tanzania Craton and its mineral deposits are less studied compared to the Yilgarn, Superior or Kapvaal Cratons. Geita Greenstone Belt is very well endowed with mineral deposits that occur in three clusters spatially associated with intrusive complexes 1) the Kukuluma, Matandani and A3 deposits associated with the Kukuluma Igneous Complex; 2) the Nyankanga, Geita Hill and Lone Cone deposits associated with the Nyankanga Igneous Complex and 3) Ridge 8, Star and Comet and Nyamulilima deposits associated with the Nyamulilima Igneous Complex. The magmatic evolution of the greenstone belt is consistent with reworking of an early mafic crust with geochemical characteristics indicative of mantle plumes to generate syn-tectonic TTG crust which in turn was remelted to generate late to post-tectonic high-K granites. At the transition between the TTG and high-K granites a series of mantle derived melts were emplaced in the greenstone sequence. These mantle derived melts are important components of the Kukuluma, Nyankanga and Nyamulilima Igneous Complexes which are spatially and temporally associated with the gold mineralization.
Graphical Abstract
