Curtin University researchers used ancient crystals from eroded rock found in river sediments in Greenland to successfully test the theory that portions of the ancient crust of the earth acted as "seeds" from which later generations of crusts grew.
The results not only advance understanding of the Earth's crust production over time, its structure and composition, but also reveal a planetary crustal growth spurt three billion years ago when mantle temperatures peaked.
Lead author Professor Chris Kirkland of Curtin University's Timescales of Mineral Systems Group said the research used the chemistry of ancient crystals preserved in river sediments in arctic Greenland to test the idea that portions of the ancient crust were used as seeds for the later growth of continents served.
"We found that crust production was widespread three billion years ago during a peak in mantle temperatures," said Professor Kirkland.
"Three billion year old magmas from the mantle had invaded an even older four billion year old crust to create rocks of mixed composition.
"Old crust appeared to be of vital importance to continent production as it acted like a life raft to preserve the crust in later stages of Earth's history.
"The increase in the age of crust production in Greenland corresponds to other regions around the world and indicates a significant widespread event that crustated relatively early in our planet's history."
Professor Kirkland said understanding crust production improved understanding of its structure and composition.
"The earth's crust is home to concentrations of economically valuable ores and minerals, but their search becomes increasingly difficult as more near-surface deposits are depleted," said Professor Kirkland.
"Understanding that the later crust is 'sown' on older, pre-existing crusts refines our understanding of how certain metals are formed and ultimately explains the habitable part of our planet."