『Abstract
Palynofacies analysis is based on transmitted light microscope
study of organic constituents isolated and concentrated by acid
and basic digestions. Published results of studies of present-day
terrestrial environments show that two complementary approaches
successfully characterize particulate organic matter (OM) from
palynofacies analyses. The first method is based on the identification
and the quantification of some typical particles (optical markers)
according to their origin (i.e. aquatic or terrestrial), their
nature (i.e. biogenic, anthropogenic, fossil), and/or their formation
(i.e. biodegradation, combustion, oxidation). The second approach
is based on the use of binary or ternary diagrams in order to
define petrographical signatures from the relative proportions
of significant organic constituents. This approach can be used
for tracking i) changes in OM composition during humification
in soil profiles, ii) transport of reworked terrestrial particles,
iii) diagenesis of peaty deposits, or iv) weathering of geological
substratum. The more advanced approach is based on the use of
some predefined optical markers and their optical signatures to
establish the relation between the OM compositions (palynofacies)
and their depositional environments. In addition, this kind of
study aims to define a modern frame of reference that can be applied
in paleoenvironmental reconstructions. This paper combines a bibliographic
review with previously unpublished data from palynofacies analyses.
The aim is to present some applied examples illustrating (1) the
main approaches developed for characterization of the particulate
OM in surficial deposits, and (2) the study of OM transfers in
terrestrial geosystems.
Keywords: organic matter; optical marker; sedimentary load; surficial
deposits; soil; carbon cycle』
1. introduction
2. Palynofacies analysis
3. Characterization of particulate OM
3.1. Optical markers
3.1.1. Aquatic (planktonic) or terrestrial (higher plant) nature
of OM
3.1.2. Origin of terrestrial organic inputs
3.1.3. Identification of fossil organic contributions
3.2. Optical signature and palynofacies composition
3.2.1. Characterization of soil OM in temperate environments
3.2.2. Depositional environments of particulate OM in alluvial
wetlands
3.2.3. Distribution of particulate OM in catchments
4. Transfers of OM in continental geosystems
4.1. Transformation of OM in the soil profiles
4.2. Organic fluxes in wetlands, lakes and rivers
4.3. Transfers of particulate OM in catchments
5. conclusions
Acknowledgements
References