New data on ancient zircons points to a transition from stagnant lid to subduction style tectonics at 3.6 Ga ago.
zircons
Impact Structure Hidden Under Arctic Ice Dates to the Paleocene
Greenland’s Hiawatha impact structure, more than 30 kilometers in diameter, is much older than previously thought, new results suggest.
Martian Meteorites Reveal Evidence of a Large Impact
By analyzing rare Martian meteorites, researchers have uncovered a crystalline structure created by a large asteroid or comet impact that potentially affected the Red Planet’s habitability.
Updating Dating Helps Tackle Deep-Time Quandaries
Geochronologists are finding fresh approaches to familiar methodologies, especially by zapping rocks with lasers to tackle classic Precambrian problems.
Oldest Pole Reversal Shows Early Earth Was Well Suited for Life
Australian rocks 3.25 billion years old preserved the oldest signs of Earth’s stable magnetic field and quickly moving crust, critical elements of life’s evolution.
Diamonds Are a Paleomagnetist’s Best Friend
Typical paleomagnetic measurements average a sample’s signal. The quantum diamond microscope helps scientists make micrometer-scale maps of magnetism, showing where a sample locked in its magnetic signatures.
Meet Jane, the Zircon Grain—Geochronology’s New Mascot
In a children’s book written by geochronologist Matthew Fox, he condenses 400 million years of history into 34 playfully poetic pages as he follows the travels of a single grain of sand.
Earth’s Continents Share an Ancient Crustal Ancestor
How did today’s continents come to be? Geological sleuths found clues in grains of sand.
Vestiges of a Volcanic Arc Hidden Within Chicxulub Crater
Scientists discovered magmatic remnants of a volcanic arc by dating granitic rocks of the middle crust excavated by, and hidden within, the Chicxulub impact crater.
A River Ran Through It
The history of river system in southeast Tibet and Indochina reconstructed using the ages of thousands of zircon sand grains in modern and ancient river sediments.