Lecture, Giada Iacono-Marziano

SGA STUDENT CHAPTER ERLANGEN
- LECTURE SERIES - MINERAL DEPOSITS -

The Mineral System of magmatic Ni-Cu-PGE sulfide deposits revisited by an experimental petrologist

Presented by Giada Iacono-Marziano
Institut des Sciences de la Terre d’Orléans

Join talk also via Zoom
Link: https://fau.zoom-x.de/j/67201634712

Dinner at a restaurant after the talk. Please contact the SGA Chapter if you want to join the dinner.

The mineral system approach interprets the formation of ore deposits in terms of source, pathway, and sink processes, with the aim of improving ore exploration. Magmatic Ni–Cu–PGE sulfide deposits form by the segregation and accumulation of immiscible sulfide melts from mafic or ultramafic magmas. The mineral system approach for these deposits mainly investigates (i) the geodynamic setting, (ii) sources and compositions of oreforming magmas, (iii) the magma migration pathway at crustal scale, (iv) magma focusing and emplacement mechanisms at deposit scale, (v) chemical and physical mechanisms for ore precipitation (Barnes et al. 2016, The mineral system approach applied to magmatic Ni-Cu-PGE sulphide deposits, Ore Geology Reviews 76). Here we discuss these points using recent experimental studies that shed light on previously neglected processes. The implications of the experimental studies are also presented in term of ore exploration at the province, camp and deposit scales. We particularly focus on magma-sediment interactions that lead to the segregation of a sulfide melt at crustal levels. At the province scale, magma emplacement within S-bearing sedimentary rocks is facilitated by the preferential injection of the magma within carbonaceous and evaporitic sediments/rocks. At the camp scale, the respective role of carbonaceous and evaporitic rocks in ore formation is discussed. We finally examine how magma-sediment interactions and the close association of the sulfide melt with the fluid phase affect ore distribution at the deposit scale. The Noril’sk-Talnakh province in Russia and the Central Lapland Greenstone Belt in Finland are used as case studies to illustrate how described processes affect ore genesis.