Most of Earth's gold and platinum should have sunk to the core, so our theories on why it’s on the surface are a mess.
March 19, 2026
Original Paper
The efficient delivery of highly-siderophile elements to the core creates a mass accretion catastrophe for the Earth
arXiv · 2603.17961
The Takeaway
We have long believed that precious metals in Earth's crust were deposited by a 'late veneer' of asteroid impacts. However, new calculations show that metals from any impactor larger than one kilometer would have dropped like a stone into the center of the planet, meaning the gold we mine today shouldn't technically be there under current models.
From the abstract
The excess abundance of highly siderophile elements (HSEs), as inferred for the terrestrial planets and the Moon, is thought to record a `late veneer' of impacts after the giant impact phase of planet formation. Estimates for total mass accretion during this period typically assume all HSEs delivered remain entrained in the mantle. Here, we present an analytical discussion of the fate of liquid metal diapirs in both a magma pond and a solid mantle, and show that metals from impactors larger than