On the photosynthetic potential in the very Early Archean oceans
  In this work we apply a mathematical model of photosynthesis to quantify the potential for photosynthetic life in the very Early Archean oceans. We assume the presence of oceanic blockers of ultraviolet radiation, specifically ferrous ions. For this scenario, our results suggest a potential for photosynthetic life greater than or similar to that in later eras/eons, such as the Late Archean and the current Phanerozoic eon. 
Daile Avila, Rolando Cardenas, Osmel Martin
q-bio.PE physics.bio-ph q-bio.SC