Fertility of subduction and post subduction magmatism associated with porphyry- and epithermal-Cu-Au mineralisation in the Aegean using zircon geochro

The UK has passed legislation to reach net zero greenhouse gas emissions by 2050. This will require new geological resources to underpin non fossil fuel transport and energy generation. Porphyry copper deposits are the world's major source of copper - a key raw material in electric motors and dynamos.

They are also notable, in certain geodynamic environments, for their enrichment in a wide range of trace elements and minerals, including "critical" elements, such as Te, Pt, Pd, Bi and Sb, used in clean energy generation. Hence, in the drive for "net zero", there will be a requirement for new porphyry-copper resources and consequently a better understanding of the key processes that result in their formation and the locations where they can be found is required.

Accessory minerals (e.g. zircon and apatite) and magma geochemistry coupled with high precision U-Pb geochronology on zircon are the focus of significant current research effort as they have the potential to distinguish fertile from barren porphyry copper systems [e.g. 1] with the aims of developing a new understanding of the magmatic and petrogenetic processes responsible for porphyry copper formation and to provide new tools for their exploration. To date, the emphasis has been on the Andes - a subduction setting.

However, post-subduction magmatism is a common phenomenon and is increasingly recognised as an important control on the formation of exceptional porphyry-epithermal style ore deposits and are, as noted above, an important source of technology elements

The Aegean is a region that has a complex, but reasonably well understood geodynamic and magmatic history over the last 33 Ma, that is predominantly post-subduction in style but also involves active, albeit slow, subduction. It also has well-developed porphyry and epithermal style mineralisation developed coevally with this geodynamic and magmatic evolution, which together provide a robust template for developing accessory mineral porphyry-copper fertility indicators in a post-subduction setting.