K. K. Yates, L. L. Robbins, 2001. "Microbial Lime-Mud Production and Its Relation to Climate Change", Geological Perspectives of Global Climate Change, Lee C. Gerhard, William E. Harrison, Bernold M. Hanson
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Microbial calcification has been identified as a significant source of carbonate sediment production in modern marine and lacustrine environments around the globe. This process has been linked to the production of modern whitings and large, micritic carbonate deposits throughout the geologic record. Furthermore, carbonate deposits believed to be the result of cyanobacterial and microalgal calcification suggest that the potential exists for long-term preservation of microbial precipitates and storage of carbon dioxide (CO2). Recent research has advanced our understanding of the microbial-calcification mechanism as a photosynthetically driven process. However, little is known of the effects of this process on inorganic carbon cycling or of the effects of changing climate on microbial-calcification mechanisms.
Laboratory experiments on microbial cellular physiology demonstrate that cyanobacteria and green algae can utilize different carbon species for metabolism and calcification. Cyanobacterial calcification relies on bicarbonate (HCO3−) utilization while green algae use primarily CO2. Therefore, depending on which carbonate species (HCO3− or CO2) dominates in the ocean or lacustrine environments (a condition ultimately linked to atmospheric partial pressure PCO2), the origin of lime-mud production by cyanobacteria and/or algae may fluctuate through geologic time. Trends of cyanobacteria versus algal dominance in the rock record corroborate this conclusion. These results suggest that relative species abundances of calcareous cyanobacteria and algae in the Phanerozoic may serve as potential proxies for assessing paleoclimatic conditions, including fluctuations in atmospheric PCO2.
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Geological Perspectives of Global Climate Change
Access A Broad Range of Paleoclimatic Studies. Current debates regarding potential man-induced modification of climate make this volume especially timely. Introductory sections address the major and minor physical controls, or drivers, that affect Earth's climate. Several chapters describe the naturally occurring range of variation of climatic conditions and illustrate past changes in global temperatures. Case studies show how ancient temperature conditions are determined, as well as new techniques that have significant potential as proxies for assessing paleoclimates. Several chapters demonstrate the magnitude and length of duration of numerous temperature variations, which occurred during geologic time periods.