Banded Iron Formations are characteristic iron-rich rocks. The deposition of these rocks occured in specific time intervals in Earth history, such as during the first Great Oxygenation Event (GOE) at ca. 2.4-2.2 billion years ago and after the Neoproterozoic Snowball Earth glaciations (Rapitan-type iron formations). A number of factors seem to have been interconnected inContinuar lendo “Microbes influence the formation of iron deposits and can be used in energy fuel cells / Micróbios influenciam na formação de depósitos de ferro e podem ser usados em células de geração de energia”
Arquivos da categoria: paleoclimate
Aragonite crystal fans in 3D
Aragonite crystal fans in three dimensional view, with pseudo-hexagonal sections in the surface where the coin is resting and prismatic sections in the side cut. Those beautiful crystals are precipitated directly on the seafloor when the ocean is supersatured in CaCO3. This happened ca. 630-540 million years ago, after a global glaciation created ice capsContinuar lendo “Aragonite crystal fans in 3D”
The Ozone Layer and Mass Extinctions
Could damage to the ozone layer cause mass extinctions? Researchers from the University of Southampton presented evidence that this happened 360 million years ago. Changes in the atmosphere chemistry allowed for UV rays to hit harder and cause mutations that led to the extinction of various life forms. Could this happen again? It’s not wiseContinuar lendo “The Ozone Layer and Mass Extinctions”