2023-10-13 08:00:00
Gold and platinum, known as ‘precious’ metals, have been admired not only for their aesthetic beauty, but also for their exceptional properties and their low presence in the Earth’s crust and mantle. However, conventional theories suggest that these heavy metals should have sunk into the Earth’s core during its formation, raising a puzzle about their abundance in the crust. Researchers from Yale University and the South-West Research Institute in the United States have shed light on this mystery with a new model that offers a compelling explanation.
The traditional model posits that in Earth’s early days, the planet experienced extreme temperatures due to gravitational contraction, radioactive decay, and impacts from asteroids and planetesimals. This would have resulted in a lava ocean into which heavier elements, such as gold and platinum, would have sunk. However, the relative abundance of these metals in the Earth’s crust questions this theory.
Earth’s first geological era is informally known as “Hadean” after the Greek underworld, in reference to its hellish conditions. (???? Simone Marchi) pic.twitter.com/nXOrUeS8yM
— Andrew Rader (@marsrader) July 19, 2020
The research led by Jun Korenaga and Simone Marchi focuses on a transient region of the Earth’s mantle, where the lower part melts while the upper part remains solid. According to scientists, this region has unique dynamic properties that allow heavy metal components to be captured and distributed throughout the mantle. This slow process, which has continued for billions of years, appears to be the key to the abundance of gold and platinum on Earth.
Simone Marchi explained that this transient region is generally formed due to the impact of large space bodies on proto-planets, strengthening his theory. According to her research, the early Earth experienced impacts from bodies equivalent to 3% of its total mass, which is more than twice the mass of the Moon. These impacts gave rise to so-called ‘low shear rate provinces’, which scientists have been trying to understand for years and which explain the abundance of gold on our planet.
#Model #Reveals #Enigma #Abundance #Gold #Platinum #Earth