Crustal evolution, intra-cratonic architecture and the metallogeny of an Archaean craton

Abstract

The generation of the Earth's continental crust modified the composition of the mantle and provided a stable, buoyant reservoir capable of capturing mantle material and ultimately preserving ore deposits. Within the continental crust, lithospheric architecture and associated cratonic margins are a first-order control on camp-scale mineralization. Here we show that the evolving crustal architecture of the Archaean Yilgarn Craton, Western Australia, played a key role in controlling the localization of camp-scale gold, iron and nickel mineralized systems. The age and source characteristics of Archaean lithosphere are heterogeneous in both space and time and are recorded by the varying Nd isotopic signature of crustal rocks. Spatial and temporal variations in isotopic character document the evolution of an intra-cratonic architecture through time, and in doing so map transient lithospheric discontinuities where gold, nickel and iron mineral systems were concentrated. Komatiite-hosted nickel deposits cluster into camps localized within young, juvenile crust at the isotopic margin with older lithosphere; orogenic gold systems are typically localized along major structures within juvenile crust; and banded iron formation (BIF)-hosted iron deposits are localized at the edge of, and within, older lithospheric blocks. Furthermore, this work shows that crustal evolution plays an important role in the development and localization of favourable sources of nickel, gold and iron by controlling the occurrence of thick BIFs, ultramafic lavas and fertile (juvenile) crust, respectively. Fundamentally, this study demonstrates that the lithospheric architecture of a craton can be effectively imaged by isotopic techniques and used to identify regions prospective for camp-scale mineralization.

Archean komatiite volcanism controlled by the evolution of early continents

“…This method is based on previous isotopic mapping of the Yilgarn Craton using the analogous Sm-Nd system (27). Importantly, the Lu-Hf data presented here replicate the features of the Sm-Nd work (27,28), with the added ability to look further back in time due to the in situ analysis of abundant inherited zircons (21).…”

A review of volcanic-hosted massive sulfide (VHMS) mineralization in the Archaean Yilgarn Craton, Western Australia: Tectonic, stratigraphic and geochemical associations

“…Champion and Sheraton, 1997;Cassidy et al, 2006;Champion and Cassidy, 2007;Czarnota et al, 2010;Pawley et al, 2012;Van Kranendonk et al, 2013;Mole et al, 2014). The Yilgarn Craton has historically been divided into a series of terranes based on distinct lithological associations, geochemistry and ages of volcanism (Gee et al, 1981;Myers, 1990;Cassidy et al, 2006).…”

Magmatic controls on the genesis of Ni–Cu±(PGE) sulphide mineralisation on Mars

“…The lateral dimension, thickness and geometry of lithospheric blocks exert a first order control on the formation and stabilisation of continents, and control the location and geochemistry of mantle melts. Begg et al (2010) and Mole et al (2013Mole et al ( , 2014 recently advocated that the lithosphere plays a key role in controlling magma chemistry and maximising magma flux to ultimately generate Ni-Cu±(PGE) sulphide mineralisation.…”