Deep marine shelf environments experienced fluctuating levels of seawater oxygenation before the Great Oxidation Event, as reflected by oscillations between nitrogen fixation and denitrification recorded by nitrogen isotopes in banded iron formations.

Combined sulfur and neodymium isotopes suggest that volatile cycling at subduction zones began 3.8 Gyr ago or earlier, according to a study of Eoarchaean mantle-derived rocks with arc-lava characteristics.

Oxygenated bottom water existed transiently on continental shelves with O₂ penetrating into underlying marine sediments by about 2.65 billion years ago, according to a study of thallium isotopes in Archaean shales.

Periods with enhanced iron and sulfide availability that promoted recycling of bioavailable phosphorus from sediments contributed to episodic development of oxygen oases in the Archaean ocean, according to analysis of trace metals, phosphorus and iron from 2.9-billion-year-old sediments.

Numerical simulations suggest the wavelength of wind ripples is controlled by the mechanics of grain–bed impacts, not grain hop length, explaining why ripples on Mars and Earth are the same scale despite very different atmospheric conditions.

The drying out of the Aral Sea has induced flow of the relatively weak asthenosphere beneath, demonstrating that human activity can influence mantle dynamics, according to numerical simulations of ground uplift measured by radar interferometry.

Davemaoite is the least abundant of the lower mantle rock-forming minerals. Despite this, it is a maverick that exerts a big influence on geochemical cycling, as Oliver Tschauner explains.

Quasicrystals have structural properties intermediate between crystalline and amorphous materials. They can be synthesized in the lab but, as Luca Bindi explains, they may also be present in natural materials formed under extreme conditions.

A record-breaking start to 2025 extends the recent period of exceptional warmth and raises questions over the rate of ongoing climate change.

Rhabdophane contains high concentrations of the rare earth elements, yet Tobias Bamforth argues that it remains underappreciated as a significant host of these critical metals.