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Ultrastructural Evidence for a Novel Accumulation of Ca in a Microbial Mat from a Slight Acidic Hot Spring
Author(s) -
PENG Xiaotong,
ZHOU Huaiyang,
YAO Huiqiang,
LI Jiangtao,
WU Zijun
Publication year - 2010
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2010.00191.x
Subject(s) - hot spring , acicular , precipitation , microbial mat , cyanobacteria , spring (device) , coprecipitation , amorphous solid , chemistry , mineralogy , transmission electron microscopy , geology , environmental chemistry , materials science , inorganic chemistry , nanotechnology , paleontology , bacteria , mechanical engineering , microstructure , physics , organic chemistry , meteorology , engineering , crystallography
Microbial mats are ecosystems that can control or induce the precipitation of calcium (Ca) carbonate on Earth through geological time. In the present study, we report on a novel accumulation of Ca, together with iron (Fe), in a microbial mat collected from a slight acidic hot spring (pH=5.9) in south China. Combining an array of approaches, including environmental scanning electron microscopy, X‐ray microanalysis, transmission electron microscopy, and selected area electron diffraction, we provide ultrastructral evidence for amorphous acicular aggregates containing Ca and Fe associated with cyanobacteria precipitating in the microbial mats. Cyanobacterial photosynthesis and exopolymeric organic matrixes are considered to be responsible for the precipitation of Ca. These amorphous acicular aggregates might imply the early stage of calcification occurring in microbial mats. Ca and Fe coprecipitation indicates another potential important way of inorganic element precipitation in hot spring microbial mats. Our results provide insight into the possible mechanism of cyanobacterial calcification and microfossil preservation in slight acidic hot spring environments.