Publication Date:
2023-11-28
Description:
In the reconstruction of bioproductivity in surface waters the extent to which a proxy has been diagenetically altered is often a matter of debate. Here we investigate how organic- and calcareous-walled dinoflagellate cysts can be used for separately estimating bioproductivity and oxygen related diagenesis. This is achieved by studying the cyst content of the most recent Eastern Mediterranean sapropel S1, that is thought to have been deposited under conditions of increased primary production in surface waters and possible anoxia in the bottom waters. Based on chemical evidence, it has been shown that the visible sapropelic layer represents only the residual lower part of what was initially a much thicker sapropel, as a result of post-depositional decay of organic matter related to oxygen penetration into the sediments. The effect of aerobic organic matter decay on the cyst associations is studied through the comparison of the unaffected, lower part of the initial sapropel and the 'oxidised' upper part. Comparing the unaffected sapropelic sediments with pre- and post-sapropelic material gives insight into the relationship between fossil cysts assemblages and palaeoproductivity.
Impagidinium aculeatum, Impagidinium patulum, Operculodinium israelianum, Polysphaeridium zoharyi and probably Impagidinium spp., Impagidinium paradoxum and Nematosphaeropsis labyrinthus are very resistant against aerobic decay and their accumulation rates appear to be primarily related to productivity in surface waters. Protoperidinium and Echinidinium species, on the other hand, are shown to be very sensitive and can be used to recognise oxygen-related decay. The calcareous-walled dinoflagellate cysts seem to be unaffected by oxic organic matter decay in Mediterranean sediments.
Keywords:
ABC26; BC; Box corer; Brigantedinium; Calciodinellum albatrosianum; Calciodinellum elongatum; Calciodinellum levantinum; Calciodinellum sp.; Counting, dinoflagellate cysts; DEPTH, sediment/rock; Dino-Atlas; Dinoflagellate cyst indeterminata; Dinoflagellate cyst reworked; Dry mass; Echinidinium spp.; Echinidinium transparantum; GeoB; Geosciences, University of Bremen; Impagidinium aculeatum; Impagidinium paradoxum; Impagidinium patulum; Impagidinium plicatum; Impagidinium sphaericum; Impagidinium strialatum; Impagidinium velorum; Lebessphaera urania; Lejeunecysta oliva; Leonella granifera; Levantine Basin; Lingulodinium machaerophorum; Melodomuncula berlinensis; Multispinula quanta; Nematosphaeropsis labyrinthus; Operculodinium israelianum; Pentapharsodinium dalei; Pixidinopsis reticulata; Polyspaeridium zoharyi; Praecalcigonellum schizosaeptum; Protoceratium reticulatum long; Protoperidinium americanum; Sample code/label; Scrippsiella lachrymosa; Scrippsiella regalis; Scrippsiella trifida; Scrippsiella trochoidea; Selenopemphix nephroides; SESAME; Southern European Seas: Assessing and Modelling Ecosystem Changes; Spiniferites; Spiniferites bentori; Spiniferites bulloideus; Spiniferites elongatus; Spiniferites membranaceus; Spiniferites mirabilis; Spiniferites pachydermus; Spiniferites ramosus; Stelladinium stellatum; Tectatodinium pellitum; Thoracosphaera heimii; TY_00_1987; Tyro
Type:
Dataset
Format:
text/tab-separated-values, 979 data points
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