Geomicrobiology: its significance for geology

The influence of picocyanobacterial photosynthesis on calcite precipitation

“…Schultze-Lam et al (1992), indicated that precipitation of calcite and the subsequent shedding off of the calcified cell wall are actually important for the Synechococcus cells as they help them to escape the suicidal effect of their own metabolism. Several authors have argued that the induction of calcite precipitation is caused by the metabolic uptake of HCO 3 - (Ferrer et al, 1988;Erlich, 1998;Thompson and Ferris, 1990;Hammes and Verstraete, 2002;Rivadenerya et al, 1994;Dittrich and Obst, 2004). The authors have suggested that during photosynthesis, HCO 3 -is transported through the membrane and dissociates within the cell into CO 2 and OH -(this equilibrium may be shifted further towards CO 2 and OH -by the enzymatic action of Carbonic anhydrase).…”

Microbial lithification in marine stromatolites and hypersaline mats

“…543 million years before present), microbially induced and/or controlled precipitation continued throughout the geological record as an active and essential player in most aquatic ecosystems [9,10]. Although less abundant than in the Precambrian, microbial precipitation is observed in a multitude of semi-confined (physically or chemically) to confined macro-and micro-environments, from the deep sea to shallow platforms and terrestrial deposits.…”

Colour origin of red sandstone beds within the Hüdai Formation (Early Cambrian), Aydıncık (Mersin), southern Turkey

“…Iron is present as Fe 2+ in primary minerals (mainly silicates) and is released during weathering in an acidic environment at low pH. Microorganisms effectively influence the kinetics of mineral alterations and formation reactions (Ehrlich, 1998;Rogers and Bennett, 2004). They interact strongly with mineral surfaces and enhance weathering through the supply of acid and strong complexing ligands (Churchman, 2000).…”