Author: Chris Kirkland, Professor of Geochronology, Curtin University In the Pilbara of Western Australia, some of Earth’s oldest rocks lie beneath the sky, as they have for billions of years. They are dark, weathered volcanic rocks, close to 3.5 billion years old, cut by veins and stewed by deep time. Their survival is remarkable. Most […]
Biochemistry • Biology • Chemistry • Geosciences • Planetary Science
Asteroids and planetesimals regularly bombarded Earth between about 4.6 billion and 3.5 billion years ago, during the Hadean and Archean eons. Because few rocks today are more than 4 billion years old, our understanding of the planet’s environment during that time is limited. However, samples from the moon and its cratered surface hint at the […]
Isotope analysis of gas from geothermal springs in Zambia could show that a new continental rift is forming . Unexpectedly high helium isotope ratios indicate that a weakness in Earth’s crust has broken through to reach the mantle beneath. This rift could eventually become a new tectonic plate boundary. In the meantime, opportunities for geothermal […]
Two years ago, in March 2024, I wrote in this blog about a decision that surprised many: the rejection of the Anthropocene as a formal geological epoch. After fifteen years of work by an international team of experts, the proposal to declare that we are now living in a new chapter of Earth’s history—one defined […]
Author: Alexander Lewis Peace, Associate Professor, Structural Geology, McMaster University Recent seismic imaging off Vancouver Island has revealed something extraordinary: a tear in the subducting oceanic plate beneath the Cascadia Subduction Zone. The finding briefly raised the public’s hopes that Cascadia might be “shutting down,” potentially lowering earthquake risk in North America’s Pacific Northwest. A […]
Earth’s atmosphere is a vast, swirling engine of weather and climate. Jet streams race across continents, storms spin into hurricanes, and invisible eddies churn the air at every scale. For decades, scientists have struggled to understand exactly how energy and swirling motion flow through these turbulent systems, especially in the layered zones where the air […]
Chemistry • DIPC Biochemistry • Evolution • Geosciences • Materials
The classic chemical garden experiment is a staple of introductory chemistry, where colorful, plant-like structures sprout from metal salt crystals dropped into a solution of sodium silicate. While these vibrant tubes look like biological life, they are entirely inorganic, driven by the physics of osmosis and the chemistry of precipitation. For decades, scientists have admired […]
Our planet has experienced dramatic climate shifts throughout its history, oscillating between freezing “icehouse” periods and warm “greenhouse” states. Scientists have long linked these climate changes to fluctuations in atmospheric carbon dioxide. However, new research reveals the source of this carbon – and the driving forces behind it – are far more complex than previously […]
Some 445 million years ago, life on Earth was forever changed. During the geological blink of an eye, glaciers formed over the supercontinent Gondwana, drying out many of the vast, shallow seas like a sponge and giving an “icehouse climate” that, together with radically changed ocean chemistry, ultimately caused the extinction of about 85% of […]
Chemistry • Ecology • Environment • Evolution • Geosciences
More than a billion years ago, in a shallow basin across what is now northern Ontario, a subtropical lake much like modern-day Death Valley evaporated under the sun’s gentle heat, leaving behind crystals of halite—rock salt. It was a very different world than the one we know today. Bacteria were the dominant form of life […]