Marine Carbonate Cements, Biofilms, Biomineralization, and Skeletogeneis: Some Bivalves Do It All

2000 ◽  
Vol 70 (5) ◽  
pp. 1129-1138 ◽  
Author(s):  
C. J.R. Braithwaite ◽  
J. D. Taylor ◽  
E. A. Glover
Keyword(s):  
Carbonate Cements ◽  
Marine Carbonate

MORPHOLOGY AND COMPOSITION OF NON-MARINE CARBONATE CEMENTS IN NEAR-SURFACE SETTINGS

1985 ◽  
pp. 337-347 ◽  
Author(s):  
HENRY S. CHAFETZ ◽  
BRUCE H. WILKINSON ◽  
KAREN M. LOVE
Keyword(s):  
Near Surface ◽  
Carbonate Cements ◽  
Marine Carbonate

The mechanism of closed-system diagenesis of marine magnesium calcite: An AEM study

1984 ◽  
Vol 42 ◽  
pp. 296-297
Author(s):  
D. F. Blake ◽  
K. C. Lohmann
Keyword(s):  
Depositional Environment ◽  
Minor Element ◽  
Chemical Information ◽  
Carbonate Cements ◽  
Marine Carbonate ◽  
Secular Variations ◽  
Require Solution ◽  
Magnesium Calcite ◽  
Precipitated Phases

A recent focus of marine carbonate research is the determination of secular variations in paleo-ocean chemistry through the study of modern and ancient marine cements. By studying the major and minor element chemistry of marine carbonate cements, it is in principle possible to infer the chemical composition of the marine waters from which such cements precipitated. However, since most inorganically precipitated phases in the marine environment are metastable, they commonly undergo chemical and mineralogic stabilization (i.e., diagenesis) in the post-depositional environment. Such processes at low temperature require solution-reprecipitation reactions involving extraneous and generally non-marine fluids, and typically lead to a loss of the chemical information contained in the original marine carbonate cements.

scholarly journals The role of bacterial urease activity on the uniformity of carbonate precipitation profiles of bio-treated coarse sand specimens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charalampos Konstantinou ◽  
Yuze Wang ◽  
Giovanna Biscontin ◽  
Kenichi Soga
Keyword(s):  
Calcium Carbonate ◽  
Calcium Chloride ◽  
Urease Activity ◽  
Coarse Sand ◽  
Carbonate Precipitation ◽  
Population Densities ◽  
Carbonate Cements ◽  
Microbially Induced Carbonate Precipitation

AbstractProtocols for microbially induced carbonate precipitation (MICP) have been extensively studied in the literature to optimise the process with regard to the amount of injected chemicals, the ratio of urea to calcium chloride, the method of injection and injection intervals, and the population of the bacteria, usually using fine- to medium-grained poorly graded sands. This study assesses the effect of varying urease activities, which have not been studied systematically, and population densities of the bacteria on the uniformity of cementation in very coarse sands (considered poor candidates for treatment). A procedure for producing bacteria with the desired urease activities was developed and qPCR tests were conducted to measure the counts of the RNA of the Ure-C genes. Sand biocementaton experiments followed, showing that slower rates of MICP reactions promote more effective and uniform cementation. Lowering urease activity, in particular, results in progressively more uniformly cemented samples and it is proven to be effective enough when its value is less than 10 mmol/L/h. The work presented highlights the importance of urease activity in controlling the quality and quantity of calcium carbonate cements.

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