The rapid increase of carbon dioxide concentration in Earth's modern atmosphere is a
matter of major concern. But for the atmosphere of roughly two-and-half billion years ago …

Abstract The Archean era (4 to 2.5 billion years ago, Ga) yielded rocks that include the
oldest conclusive traces of life as well as many controversial occurrences. Carbonaceous …

Molecular oxygen (O2) is, and has been, a primary driver of biological evolution and shapes
the contemporary landscape of Earth's biogeochemical cycles. Although “whiffs” of oxygen …

The discovery of Asgard archaea, phylogenetically closer to eukaryotes than other archaea,
together with improved knowledge of microbial ecology, impose new constraints on …

In the low-oxygen Archean world (> 2400 million years ago), seawater sulfate
concentrations were much lower than today, yet open questions frustrate the translation of …

The distribution of sulfur isotopes in geological materials reveals information about Earth
history and biogeochemical processes. Research during the last several decades has used …

The Precambrian history of our planet is marked by two major events: a pulse of continental
crust formation at the end of the Archaean eon and a weak oxygenation of the atmosphere …

Abstract The Proterozoic Eon spans Earth's middle age during which many important
transitions occurred. These transitions include the oxygenation of the atmosphere …

It has been hypothesized that, before widespread oxygenation about 2.45 billion years ago,
the Earth's atmosphere contained an organic haze similar to that on Titan. However, these …

Conditions at the surface of the young (Hadean and early Archean) Earth were suitable for
the emergence and evolution of life. After an initial hot period, surface temperatures in the …