Privileged Planet: measuring Earth's early crust (Introduction)

by David Turell , Tuesday, September 24, 2019, 19:21 (1678 days ago) @ David Turell

More than originally thought:

https://phys.org/news/2019-09-earth-crust.html

"A new international study led by a Monash geoscientist has found that more crust was formed on the early Earth than previously thought.

"The study, published today in Nature GeoScience, is part of the Monash "Pulse of the Earth' research project and has major has implications for the rate of crustal growth in Earth's earliest times and the evolution of global tectonics.

"The continental crust hosts the resources on which we depend and its evolution controls the environment in which we live.

"'Constraining the growth and destruction of the continental crust in Earth's earliest history is complicated by a severe bias in the rocks preserved at Earth's surface," said lead study author Dr. Alex McCoy-West.

"'Our study shows that up to four times the present amount of proto-crust was formed in the first billion years of Earth's history.

***

"In this latest study researchers used ultra-precise molybdenum stable isotope compositions to constrain the composition of the mantle, which has been shown to have been constant for the last three-and-a-half billion years of Earth's history.

"This mantle composition was then used to calculate through mass balance the volume of crust on the early Earth.

"'Traditional crustal growth models cannot account for a scenario in which there was more continental crust than is preserved today," Dr. McCoy-West said.

"'The unique modelling approach applied here is not pinned to the present-day crustal record and therefore has provided a new perspective on the amount of crust in Earth's earliest history," he said.

"'Our study is significant because until this period of extensive crustal growth and recycling had finished the stable continental crust required for the evolution of life would not have existed.'" (my bold)

Comment: the Earth's crust with tectonic plates moving and diving under one another creates control cycles that create a stable environment for life to exist. Clever planning on the part of God.