Nav: Home

Evidence for plate tectonics on earth prior to 3.2 billion years ago

April 22, 2020

New research indicates that plate tectonics may have been well underway on Earth more than 3.2 billion years ago, adding a new dimension to an ongoing debate about exactly when plate tectonics began influencing the early evolution of the planet. An analysis of lingering magnetism in rocks from the nearly 3.2 billion year-old Honeyeater Basalt of the East Pilbara Craton, a stable block of crust in Western Australia, provides strong evidence for a large change in the latitude of the block relative to the Earth's magnetic poles between 3.35 and 3.18 billion years ago. This evidence pushes back the date for the onset of modern plate tectonics to the late Paleoarchean time period, supporting the theory that changes in the crust have resulted from continuous, uniform processes similar to those we observe today - or at least that the crust has experienced intermittent switching between episodes of movement and immobility. Alec Brenner and colleagues note that these findings will contribute to scientists' understanding of how Earth's crust formed and how plate tectonics may have evolved on other planets. A defining feature of modern plate tectonics is the plates' gradual but steady horizontal motion. Beneath our feet, these titanic slabs of rock collide, pull apart and slide past each other, molding mountains and unleashing earthquakes that rattle the world above. But while plate tectonics is central to the evolution of Earth as we know it, scientists have been uncertain about when, exactly, this geologic process began. To determine whether the lithospheric plates experienced significant motion before the early Neoarchean period some 2.8 billion years ago, Brenner et al. extracted samples from a total of 235 magnetically oriented Honeyeater Basalt cores - igneous rocks that retain a record of Earth's magnetic field at the time of their crystallization. Since the researchers knew the ages of rocks that crystallized at different times within a single block of the crust, they were able to deduce changes in the block's latitude over millions of years. They found that this section of crust drifted at an average rate of at least 2.5 centimeters per year - a velocity comparable to plate motion rates observed today.
-end-


American Association for the Advancement of Science

Related Evolution Articles:

Genome evolution goes digital
Dr. Alan Herbert from InsideOutBio describes ground-breaking research in a paper published online by Royal Society Open Science.
Paleontology: Experiments in evolution
A new find from Patagonia sheds light on the evolution of large predatory dinosaurs.
A window into evolution
The C4 cycle supercharges photosynthesis and evolved independently more than 62 times.
Is evolution predictable?
An international team of scientists working with Heliconius butterflies at the Smithsonian Tropical Research Institute (STRI) in Panama was faced with a mystery: how do pairs of unrelated butterflies from Peru to Costa Rica evolve nearly the same wing-color patterns over and over again?
Predicting evolution
A new method of 're-barcoding' DNA allows scientists to track rapid evolution in yeast.
Insect evolution: Insect evolution
Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have shown that the incidence of midge and fly larvae in amber is far higher than previously thought.
Evolution of aesthetic dentistry
One of the main goals of dental treatment is to mimic teeth and design smiles in the most natural and aesthetic manner, based on the individual and specific needs of the patient.
An evolution in the understanding of evolution
In an open-source research paper, a UVA Engineering professor and her former Ph.D. student share a new, more accurate method for modeling evolutionary change.
Chemical evolution -- One-pot wonder
Before life, there was RNA: Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich show how the four different letters of this genetic alphabet could be created from simple precursor molecules on early Earth -- under the same environmental conditions.
Catching evolution in the act
Researchers have produced some of the first evidence that shows that artificial selection and natural selection act on the same genes, a hypothesis predicted by Charles Darwin in 1859.
More Evolution News and Evolution Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Making Amends
What makes a true apology? What does it mean to make amends for past mistakes? This hour, TED speakers explore how repairing the wrongs of the past is the first step toward healing for the future. Guests include historian and preservationist Brent Leggs, law professor Martha Minow, librarian Dawn Wacek, and playwright V (formerly Eve Ensler).
Now Playing: Science for the People

#566 Is Your Gut Leaking?
This week we're busting the human gut wide open with Dr. Alessio Fasano from the Center for Celiac Research and Treatment at Massachusetts General Hospital. Join host Anika Hazra for our discussion separating fact from fiction on the controversial topic of leaky gut syndrome. We cover everything from what causes a leaky gut to interpreting the results of a gut microbiome test! Related links: Center for Celiac Research and Treatment website and their YouTube channel
Now Playing: Radiolab

The Flag and the Fury
How do you actually make change in the world? For 126 years, Mississippi has had the Confederate battle flag on their state flag, and they were the last state in the nation where that emblem remained "officially" flying.  A few days ago, that flag came down. A few days before that, it coming down would have seemed impossible. We dive into the story behind this de-flagging: a journey involving a clash of histories, designs, families, and even cheerleading. This show is a collaboration with OSM Audio. Kiese Laymon's memoir Heavy is here. And the Hospitality Flag webpage is here.