A team of researchers challenges the widely accepted hypothesis about the formation of Earth’s crust, positing ongoing gradual alterations rather than a swift deceleration approximately 3 billion years ago. Utilizing data from more than 600,000 global rock samples, the team introduces a fresh methodology to map Earth’s crustal development. This new approach not only suggests a more incremental growth but also provides valuable perspectives on the formation and diversity of planets, including noteworthy comparisons with Venus.
Contrary to popular theories suggesting a rapid deceleration in the growth of Earth’s crust around 3 billion years ago, a Penn State-led study offers evidence of a prolonged, continual process of crustal transformation. These findings dispute the mainstream notion of early, accelerated tectonic plate formation in Earth’s geological past.
This groundbreaking research has been published in the academic journal Geochemical Perspectives Letters.
According to the study’s lead author, Jesse Reimink, Assistant Professor of Geosciences, the work sheds light on an essential question concerning Earth and may offer key insights into the development of other celestial bodies.
Reimink states, “The prevalent theory posited a turning point roughly 3 billion years ago, suggesting that Earth was a stagnant-lid planet with negligible tectonic activity prior to a sudden transition to a tectonically active state. Our research disproves this assumption.”
To create what can be termed as the ‘crustal growth curve,’ researchers relied on an extensive collection of over 600,000 rock samples forming the Earth’s rock record database. Scientists worldwide, including those from Penn State, have assessed each sample to determine its geochemical constituents and age. The team opted for rock samples over mineral samples, asserting that rocks provide a more sensitive and unbiased measure over geological timescales.
Aware of the decreasing reliability of the mineral record as a temporal indicator, the scientists recreated the crustal growth curve employing rock samples. They devised a specialized technique to ascertain how igneous rocks from millions of years ago had been altered and transformed over time. Utilizing experimental data and advanced mathematical models, they analyzed various processes that rocks could undergo, such as sedimentation through weathering or remelting in the mantle.
Reimink elaborated, “We quantified the extent of rock reworking by examining the composition of igneous rocks through a novel approach that isolates the sedimentary proportion.”
The team employed these calculations to adjust for the reworking observed in the rock record. Following this, they contrasted their newly established growth curve against rates obtained from mineral records by other scholars.
Reimink and his collaborators suggest that Earth’s crust exhibits a pattern consistent with the mantle’s behavior, indicating a relationship between the two. While the concept of gradual crustal growth is not new, this is the first study that corroborates this idea using the rock record as evidence.
Reimink warns, however, that while the research enhances current understanding, it does not offer a conclusive answer to the intricacies of crustal growth. The data points available are insufficient to fully capture the temporal and spatial complexities of Earth’s crust. He believes that continued scrutiny of existing data may enrich our understanding of planetary formations, including planets like Venus that lack tectonic plates and could serve as contemporary analogs for early Earth.
Reimink poses important questions, asking, “When and why did Earth and Venus diverge? This rate of crustal growth provides significant insights into the varying evolutionary paths of planets.”
The study, titled “A whole-lithosphere view of continental growth,” was published on August 3, 2023, and authored by J.R. Reimink, J.H.F.L. Davies, J.-F. Moyen, and D.G. Pearson. Contributors include Joshua Davies of the University of Quebec at Montreal; Jean-François Moyen of the University of Lyon, France; and D. Graham Pearson of the University of Alberta, Canada.
Partial funding for this research was provided by the Natural Sciences and Engineering Research Council of Canada.
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Frequently Asked Questions (FAQs) about Earth’s crust formation
What is the main finding of the new research led by Penn State?
The principal discovery of the research is that the formation of Earth’s crust has been a slow and ongoing process, contradicting existing theories that propose a rapid deceleration approximately 3 billion years ago.
Who led the research and where was it published?
The research was led by Jesse Reimink, an Assistant Professor of Geosciences at Penn State. The findings were published in the academic journal Geochemical Perspectives Letters.
What methodology did the researchers use for their study?
The researchers analyzed over 600,000 rock samples from around the world. They developed a unique method for assessing how igneous rocks dating back millions of years have been altered and transformed over time.
Why did the researchers choose rock samples over mineral samples?
Rock samples were chosen over mineral samples because they offer a more sensitive and unbiased measure over long geological time scales. The researchers believe that the mineral record’s reliability decreases with time.
What implications does this research have for our understanding of other planets?
The research provides valuable perspectives on planetary formations and may hold key insights into the development of other celestial bodies, notably Venus, which lacks tectonic plates and could serve as a modern-day example of early Earth.
How many scientists contributed to the study, and from which institutions?
In addition to Jesse Reimink from Penn State, contributors included Joshua Davies of the University of Quebec at Montreal, Jean-François Moyen of the University of Lyon, France, and D. Graham Pearson of the University of Alberta, Canada.
Was the research funded, and if so, by whom?
The Natural Sciences and Engineering Research Council of Canada partially funded the research.
What questions does this research raise for future study?
The research opens up questions about the evolutionary paths of planets, particularly the diverging courses of Earth and Venus. It also suggests the need for further scrutiny of existing data to deepen our understanding of planetary formations.
More about Earth’s crust formation
- Geochemical Perspectives Letters Journal
- Penn State Department of Geosciences
- Natural Sciences and Engineering Research Council of Canada
- Overview of Earth’s Geological History
- Tectonic Plates and Earth’s Crust: Established Theories
- Comparative Planetology: Earth and Venus
7 comments
So we’ve been wrong bout Earth’s crust all this time? Fascinatin to think how this could change our view on planetary evolution.
Jesse Reimink and his team are changing the game. Cant wait to see how this shapes up future research. kudos!
Wow, this is mindblowing stuff. Always thought the Earth’s crust was more or less set in stone (pun intended) billions of yrs ago. Who knew!
Not convinced yet. More data points are needed for such a groundbreaking theory. Let’s not jump the gun, ppl.
This is big news. Could also have implications for how we explore other planets in future. exciting times!
slow and steady wins the race, huh? Guess Earth took its sweet time forming its crust. Amazing what science can discover.
This kinda makes you wonder what else we got wrong about our planet. And the mention of Venus? Intriguing!