The Gilding of the Earth

It is well known that Archaean terrains of the different continents throughout the world are repositories to major deposits of gold and other metals. The reasons for such endowment have been debated extensively. Being a siderophile element, much of the gold and related precious metals segregated to the core by 4.5 Ga through both the earlier event of core formation and the subsequent moon-forming impact, leaving a mantle with depleted characters, as found out from the 4.0 Ga old Isua rocks of Greenland by Wildbold and others (Nature, 2011) based on tungsten isotope studies (• W = 0.15). It has been surmised that the gold and precious metals segregated in the core can ‘pave the entire surface of the earth with a layer of gold four meters thick’