0000000000300136
AUTHOR
Marc De Rafélis
Experimental and natural cathodoluminescence in the shell of Crassostrea gigas from Thau lagoon (France): ecological and environmental implications.
We present a cathodoluminescence (CL) study of growth layer deposition in the shell of the oyster Crassostrea gigas. CL is based on the physical properties of lattice-bound manganese (Mn2+), which is the main activator in calcium carbonate. Our study involved chemical marking by immersing individuals in seawater to which manganese chloride had been added, and subsequent reading of the shell with CL microscopy coupled with numeric treatment of microphotographs; CL emission was analyzed using a scanning electron microscope coupled to a spectrometer. Since the marking did not harm the oysters, repeated markings were possible, allowing validation of the inferences made from analysis of the shel…
Specifications for carbonate content quantification in recent marine sediments using Rock-Eval pyrolysis
11 pages; International audience; The amount of CaCO3 in sediments and/or sedimentary rocks is usually measured by calcimetry while the nature of the carbonates is determined by X-ray diffraction. Recently, a carbonate recognition method based on the results of Rock-Eval pyrolysis was proposed in 2014 by Pillot et al. [1]. Rock-Eval pyrolysis is also widely used for the characterization of recent sediments. However, later in 2015 Baudin et al. [2] noticed that some of the characteristics of recent sediments tended to produce different results from those of more classical Rock-Eval analyses, causing bias in interpretations.In this study, the thermal stability of fossil and recent marine carb…