Late Quaternary Mediterranean sapropels II. Organic geochemistry and palynology of S1 sapropels and associated sediments

Haven, H Lo ten; Baas, Marianne; Leeuw, J.W. de; Schenck, P.A.; Brinkhuis, Henk

doi:10.1016/0009-2541(87)90160-4

Cited by 30 publications

(4 citation statements)

References 39 publications

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“…A relatively high siliciclastic sedimentation rate, together with the absence of anoxic bottom water conditions (thus causing enhanced oxidation and dilution of organic matter) probably lead to lower T0C in the Lingula bands. A comparable situation was observed in Mediterranean sapropels, which tend to become thicker and therefore show 'diluted' T0C towards the Nile delta (ten Haven et at., 1987). The higher T0C of the lacustrine bands probably has to be explained by a combination of a rather slow sedimentation rate plus a high influx of (non-degradable) organic matter.…”

Section: Discussionsupporting

confidence: 63%

Geochemistry of marine and lacustrine bands in the Upper Carboniferous of the Netherlands

Kombrink

Zwan

et al. 2008

Netherlands Journal of Geosciences

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Geochemical studies on Upper Carboniferous marine bands showed that marked enrichment in redox-sensitive trace elements (uranium (U), vanadium (V), molybdenum (Mo)) mostly occur if they contain Goniatites. Goniatites indicate deposition in relatively distal and deep marine environments. In contrast, Westphalian marine bands found in the Netherlands predominantly show a Lingula facies, indicating deposition in a nearshore environment. These Lingula marine bands are mostly lacking significant trace element enrichments. The aim of this paper is to explain the mechanisms causing the differences in geochemical characteristics between distal (Goniatites facies) and proximal (Lingula facies) marine bands. Geochemical analyses (total organic carbon (TOC), sulfur (S), major and trace elements) were carried out on a selection of these marine bands. Furthermore, a comparison was made with some lacustrine bands which broadly show the same sedimentary development as the Lingula marine bands. The results show that the Lingula marine bands, in contrast to the Goniatites and lacustrine bands, are characterised by low organic carbon contents (1 – 2 wt.%). A relatively high input of siliciclastics probably prevented the accumulation of organic-rich layers (dilution effect). In turn, low organic carbon contents most likely prevented the effective scavenging of trace elements. Although the lacustrine bands are characterised by high TOC contents, here the limited availability of trace elements in fresh water forms the best explanation for low trace metal enrichments. Since marine bands form stratigraphically important horizons in the Upper Carboniferous, many attempts have been made to recognise marine bands using well logs (gamma-ray). The results from this study show that using gamma-ray devices (detecting U-enrichments), only marine bands in a Goniatites facies are clearly recognised while Lingula marine bands are not detected.

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Section: Discussionsupporting

confidence: 63%

Geochemistry of marine and lacustrine bands in the Upper Carboniferous of the Netherlands

Kombrink

Zwan

et al. 2008

Netherlands Journal of Geosciences

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“…However, if this were the case, the ␦ 13 C org in Mediterranean sapropelic sediments would be lighter towards the Nile, which is the most important freshwater source in the Mediterranean. Analyses performed on Pliocene sapropels [Nijenhuis and de Lange, 2000], and on the Quaternary sapropel S1 [Ten Haven et al, 1987], show the opposite trend. The eastward tendency towards less negative values may indicate that the light land-derived CO 2 inputs are counterbalanced by gradual 12 C depletion, supported by a high productivity, in the west-east Mediterranean surface flow.…”

Section: Pristine Organic Content Of the Dark Layersmentioning

confidence: 94%

Sapropel-like Pliocene sediments of Sicily deposited under oxygenated bottom water

Daux

Foucault

Melieres

et al. 2006

Bulletin De La Société Géologique De France

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The Pliocene Punta Piccola series, deposited on the Sicily sill at 100-400 m depths, consists of alternating whitish hemipelagic marl and carbonate-poor, organic-carbon-richer, brownish dark marl. The rhythmic bedding is interpreted to result from the precession driven alternation of more or less humid periods. In the present study, we compare the mineralogical and geochemical composition (isotope ratios of oxygen and carbon; Ca, Mn, Mg, Sr, and Fe concentrations) of the carbonate fractions of the whitish marl to those of the dark layers to evaluate the environmental changes that likely produced these alternations.High Mn concentrations in the dark layers, and the occurrence of pseudo-kutnahorite (Mn-Ca mixed carbonate), bioturbation, ostracodes, and benthic foraminifera favour the hypothesis of the dark-layer deposition taking place under oxygen-bearing bottom waters. The original value of the concentration of the organic carbon in the dark layers of Punta Piccola, estimated from the ␦ 13 C measured in the carbonate fraction, was higher than the post-diagenetic one. It may have reached 7% in the dark layer 107, which was therefore a true sapropel at the time of deposition. This result indicates that anoxic conditions are not a prerequisite for sapropelic sediment formation. However, the pristine concentration of the organic carbon in the dark layers at Punta Piccola is lower than those of coeval sapropels cored in the nearby deep settings, which were deposited under an anoxic water column. This difference may result from the effect of water column anoxia on the organic carbon content.Diagenetic reactions took place in the dark layers through the oxidation of large amounts of organic matter. The dissolution of primary calcium carbonates (biogenic in origin) and the reduction of Fe and Mn oxyhydroxides led the interstitial solutions to be supersaturated towards Mn-rich calcite and/or pseudo-kutnahorite. The secondary carbonates are Mg-enriched and Sr and Fe-depleted. The negative shifts of the ␦ 18 O signal in the carbonates of the dark layers of Punta Piccola are consistent with an increased river discharge in the Mediterranean at the time of deposition. Sédiments pseudo-sapropéliques pliocènes de Sicile déposés sous des eaux de fond oxydantesMots clés. -Sapropèles, Méditerranée, Manganese, Diagenèse précoce, Anoxie.Résumé. -Les séries pliocènes de Punta Piccola, déposées sur le seuil de Sicile à 100-400 m de profondeur, sont des alternances de marnes blanchâtres hémipélagiques et de marnes brunâtres pauvres en carbonates et riches en carbone organique. Ces dépôts cycliques résulteraient de l'alternance de période plus ou moins humides, rythmées par les cycles de précession. Dans cette étude, nous comparons les compositions minéralogiques et chimiques (composition isotopique du carbone et de l'oxygène, concentrations en calcium, manganese, magnesium, strontium et fer) des fractions carbonatées des marnes blanchâtres à celles des marnes sombres pour évaluer les changements environnementaux susceptibles de conduire...

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“…These results may indicate the occurrence of a selective preservation in depth of high Fig. 2 Distributions of a n-alkanes b n-fatty acids c n-alkanols (normalized to the most abundant homologue within each trace) Environ Chem Lett (2011) 9:453-464 457 Regular isoprenoids phytane (Ph) and pristane (Pr) were detected, most probably arising from the phytol side chain of chlorophyll, although chromans and/or tocopherols have been suggested to be additional potential sources (Ten Haven et al 1987;Li et al 1995). Phytol (C 20 isoprenoid alcohol) was detected together with the n-alkanols series (Table 3).…”

Section: Study Of Soil Lipids By Gc-msmentioning

confidence: 96%

Geochemical and ecological significance of soil lipids under Rhododendron ponticum stands

et al. 2010

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The bio-geographical significance of Rhododendron ponticum spp. baeticum (Ericaceae) as a relict species is well recognized. However, out of its native habitat it is an invasive exotic considered a major threat to natural ecosystems in areas of Atlantic Western Europe. The studies on the impact of Rhododendron influence on soil organic matter composition and associated ecological implications, i.e. presence of bioactive compounds with ecological significance, are limited. This work describes the soil lipid assemblage in three sites under Rhododendron stands and adjacent sites with deciduous oak (Quercus canariensis), both in their native habitats in Southern Spain (Sierra de Luna, Cádiz). The results are discussed in terms of organic matter dynamics and the presence of molecules that may be associated with Rhododendron invasive success. The soils are acid Xerochrepts formed on siliceous sands. Composite soil samples were taken at two depths (0-10 cm and 10-20 cm) and soxhlet extracted with a dichloromethanemethanol mixture (3:1). Soil lipid assemblage was studied by GC/MS after fractionation and appropriate derivatization of extracts. The qualitative chemical composition of soil extractable lipids under Rhododendron is reported here for the first time. Our results show that soil n-alkane and fatty acid distributions are compatible with an input from plant epicuticular waxes, as well as with the occurrence of selective preservation of long-chain fatty acids with depth. The pattern of short-chain n-alkanes found in surface samples indicates an anthropogenic contamination threat from nearby industrialized areas of ''Campo de Gibraltar''. The presence of branched iso and anteiso C 15 and C 17 , b-hydroxy fatty acids and the sterol brassicasterol points to high microbial soil activity. Finally, the pentacyclic triterpenes taraxerone and taraxerol were detected in soils with Rhododendron but not with Quercus. These are known bioactive plant compounds and could be related with the effectiveness of Rhododendron as an invasive exotic species.

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Late Quaternary Mediterranean sapropels II. Organic geochemistry and palynology of S1 sapropels and associated sediments

Cited by 30 publications

References 39 publications

Geochemistry of marine and lacustrine bands in the Upper Carboniferous of the Netherlands

Geochemistry of marine and lacustrine bands in the Upper Carboniferous of the Netherlands

Sapropel-like Pliocene sediments of Sicily deposited under oxygenated bottom water

Geochemical and ecological significance of soil lipids under Rhododendron ponticum stands

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