Subaerial Emergence of Continents on Archean Earth
Abstract
The emergence of continental crust above sea level influences Earth's surface environments and climate patterns, and it creates diverse habitats that promote biodiversity. Earth exhibits bimodal hypsometry with elevated continents and a submerged seafloor. However, it remains elusive when and how this unique feature was first established. The geological record suggests the presence of subaerial landmasses between ca. 3.8 and 2.4 billion years ago (Ga), but their spatial extent and longevity remain unclear. Further, the tectonic processes governing the proportion of continental land to ocean basins and topography during this period are poorly understood. Here, we synthesize a variety of geological and geochemical proxies to suggest that crustal emergence did occur in the early-to-mid Archean, primarily exposing precratonized volcanic crust for brief time periods. Stable continental crust on a regional scale (as cratons) began emerging around ca. 3.2–3.0 Ga, facilitated by the development of thick, stable cratonic lithospheres. Over hundreds of millions of years, voluminous magmatism within a plateau-type setting led to the formation of thick, felsic crust and depleted mantle keels, allowing cratons to rise above sea level via isostatic adjustment. The areal extent of emergent land increased from ca. 3.0 to 2.5 Ga owing to the formation of more cratons, likely coinciding with the onset of plate tectonics, and culminated around ca. 2.5–2.2 Ga when land surface area and…
Read the paper
Related studies
- Understanding the factors influencing fall armyworm (Spodoptera frugiperda J.E. Smith) damage in African smallholder maize fields and quantifying its impact on yield. A case study in Eastern Zimbabwe
- Alarming situation of emerging H5 and H7 avian influenza and effective control strategies
- Livestock and food security: vulnerability to population growth and climate change
- Atmosphere–ocean oxygen and productivity dynamics during early animal radiations
- Characterization of the global distribution and diversified plasmid reservoirs of the colistin resistance gene mcr-9
- The global seroprevalence of Toxoplasma gondii in pigs: A systematic review and meta-analysis
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.