Abstract Exposed continents are one of Earth's major characteristics. Recent studies on ancient ocean volume and exposed landmasses suggest, however, that early Earth was possibly a water world, where any significant landmass unlikely to have risen above sea level. On modern Earth, the thickness continental crust seems be controlled by level buoyancy crust. Simply applying this concept Archean ...

The observed seismic anisotropy of the southern African mantle from both shear-wave splitting and surface wave observations provides important constraints on modes of mantle deformation beneath this ancient continent. We find that the mantle anisotropy beneath southern Africa is dominated by deformational events in Archean times occurring within the lithosphere, rather than present-day processe...

Archean Quartzose Rocks at Akilia, Greenland Fedo and Whitehouse (1) presented data to support their hypothesis that granulite grade quartz magnetite rocks on the island of Akilia, southwest Greenland—which are conformably interposed with pyroxenite and hornblendite units that date from before 3830 million years ago (Ma) (2–4)—had a metasomatic ultramafic igneous origin. They offered that inter...

The Earth's atmosphere has continually evolved since its formation through interactions with the mantle as well loss of volatile species to space. Atmospheric xenon isotopes show a unique and progressive evolution during Archean that stopped around Archean-Proterozoic transition. Xe isotope composition early been previously documented analysis fluid inclusions trapped within quartz barite. Whet...

Understanding the origin and different phases of the development of the Earth has long been a motivation for fundamental research in the geosciences. The climate of the Archean Eon (3.8 – 2.5 billion years ago), the time period in which life emerged, is especially puzzling: In a world very different from today, when the planet was spinning faster about its own axis and had a much smaller contin...

The Archean Earth (3.8 to 2.5 billion years ago) was probably enshrouded by a photochemical haze composed of fractal aggregate hydrocarbon aerosols. The fractal structure of the aerosols would have had a strong effect on the radiative properties of the haze. In this study, a fractal aggregate haze was found to be optically thick in the ultraviolet wavelengths while remaining relatively transpar...

Phosphorus sets the pace of marine biological productivity on geological time scales. Recent estimates of Precambrian phosphorus levels suggest a severe deficit of this macronutrient, with the depletion attributed to scavenging by iron minerals. We propose that the size of the marine phosphorus reservoir was instead constrained by muted liberation of phosphorus during the remineralization of bi...

Early geodynamic processes modeled the surface of the Earth, providing suitable environments and energy sources for the development of life. Studying the ancient biogeochemical cycles is thus a valuable way to understand the physicochemical conditions of the early environments, such as the redox state of the primitive oceans and the atmosphere. To investigate early biogeochemistries, the measur...