Oleanane parameter: Verification by quantitative study of the biomarker occurrence in sediments of the Niger delta

Ekweozor, C. M.; Telnæs, N.

doi:10.1016/0146-6380(90)90057-7

Cited by 71 publications

(27 citation statements)

References 7 publications

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“…Note that these degradation products occur in much lower concentrations than their precursors, taraxerol and b-amyrin. Taraxer-14-ene and olean-12-ene are early diagenesis products of taraxerol and b-amyrin (Figure 3; Ten Haven and Rullkotter 1988;Ekweozor and Telnaes 1990). The presence of the former in floc and sediments at sites 6 and 7 could be indicative that the mangrovederived OM is prone to early diagenetic transformations.…”

Section: Lipid Biomarkersmentioning

confidence: 99%

“…Whilst coupling based on several geochemical proxies was observed for the MEST floc/sediment pairs, Figure 3. Formation of taraxer-14-ene through diagenesis of taraxerol and b-amyrin, common components of mangroves (after Ten Haven and Rullkotter 1988;Ekweozor and Telnaes 1990). the significant changes in OM preservation (based on pigments, PUFAS and taraxerol degradation products) leads to an overall decoupling of these matrices at the MEST sites.…”

Section: Lipid Biomarkersmentioning

confidence: 99%

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Organic Biogeochemistry of Detrital Flocculent Material (Floc) in a Subtropical, Coastal Wetland

et al. 2006

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Flocculent materials (floc), in aquatic systems usually consist of a non-consolidated layer of biogenic, detrital material relatively rich in organic matter which represents an important foodweb component for invertebrates and fish. Thus, variations in its composition could impact food webs and change faunal structure. Transport, remineralization rates and deposition of floc may also be important factors in soil/sediment formation. In spite of its relevance and sensitivity to external factors, few chemical studies have been carried out on the biogeochemistry of floc material. In this study, we focused on the molecular characterization of the flocculent organic matter (OM), the assessment of its origin and its environmental fate at five stations along a freshwater to marine ecotone, namely the Taylor Slough, Everglades National Park (ENP), Florida. To tackle this issue, suspended, unconsolidated, detrital floc samples, soils/sediments and plants were analyzed for bulk properties, biomarkers and pigments. Both geochemical proxies and biomass-specific biomarkers were used to assess OM sources and transformations. Our results show that the detrital organic matter of the flocculent material is largely regulated by local vegetation inputs, ranging from periphyton, emergent and submerged plants and terrestrial plants such as mangroves, with molecular evidence of different degrees of diagenetic reworking, including fungal activity. Evidence is presented for both hydrodynamic transport of floc materials, and incorporation of floc OM into soils/sediments. However, some molecular parameters showed a decoupling between floc and underlying soil/sediment OM, suggesting that physical transport, incorporation and degradation/ remineralization of OM in floc may be controlled by a combination of a variety of complex biogeochemical variables including hydrodynamic transport, hydroperiod characteristics, primary productivity, nutrient availability, and OM quality among others. Further investigations are needed to better understand the ecological role of floc in freshwater and coastal wetlands.

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Section: Lipid Biomarkersmentioning

confidence: 99%

Section: Lipid Biomarkersmentioning

confidence: 99%

Organic Biogeochemistry of Detrital Flocculent Material (Floc) in a Subtropical, Coastal Wetland

et al. 2006

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“…This suggests that the studied mudstones from Lambir, Miri and Tukau formations were deposited under prevailing oxic conditions. The presence of oleananes in the samples indicates angiosperm input in rocks of late Cretaceous or younger age [47] or to a related plant type that possessed the availability to synthesis oleanane precursors [21,48]. The measureable amounts of oleanane in all the studied mudstone samples is a strong indicator of terrestrial angiosperm plant input in the West Baram delta province.…”

Section: Terpanes and Steranesmentioning

confidence: 85%

Geochemical characterization of Neogene sediments from onshore West Baram Delta Province, Sarawak: paleoenvironment, source input and thermal maturity

Togunwa

Abdullah

2017

Open Geosciences

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Abstract:The Neogene strata of the onshore West Baram Province of NW Borneo contain organic rich rock formations particularly within the Sarawak basin. This basin is a proven prolific oil and gas province, thus has been a subject of great interest to characterise the nature of the organic source input and depositional environment conditions as well as thermal maturation. This study is performed on outcrop samples of Lambir, Miri and Tukau formations, which are of stratigraphic equivalence to the petroleum bearing cycles of the offshore West Baram delta province in Sarawak. The investigated mudstone samples are organic rich with a total organic carbon (TOC) content of more than 1.0 wt.%. The integration of elemental and molecular analyses indicates that there is no significant variation in the source input between these formations. The investigated biomarkers parameters achieved from acyclic isoprenoids, terpanes and steranes biomarkers of a saturated hydrocarbon biomarkers revealed that these sediments contain high contribution of land plants with minor marine organic matter input that was deposited and preserved under relatively oxic to suboxic conditions. This is further supported by low total sulphur (TS), high TOC/TN ratios, source and redox sensitive trace elements (V, Ni, Cr, Co and Mo) concentrations and their ratios, which suggest terrigenous source input deposited under oxic to suboxic conditions. Based on the analysed biomarker thermal maturity indicators, it may be deduced that the studied sediments are yet to enter the maturity stage for hydrocarbon generation, which is also supported by measured vitrinite reflectance values of 0.39-0.48% Ro.

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“…An outstanding biomarker in the crude oils is the occurrence of 18α(H) oleanane, which is referred to an input of angiosperms (Ekweozor et al 1979;Ekweozor and Udo 1988;Riva et al 1988;Ekweozor and Telnaes 1990;Nwachukwu et al 1995;Haack et al 2000;Eneogwe and Ekundayo 2003;Eneogwe 2004). The oleanane index after Ekweozor and Telnaes (1990) (oleanane/C 30 hopane) is about 1 for all oils.…”

Section: Hopanes and Steranes As Maturity Parametermentioning

confidence: 99%

Geochemical characterization of crude oils from well ‘X’, Agbada formation, onshore Nigeria

Nyantakyi

Nagre

et al. 2016

Arab J Geosci

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This article characterizes crude oil samples from well 'X' in onshore Nigeria. The objective of this research is to characterize the geochemical features of crude oils. A total of 10 crude oil samples collected from well X, onshore Nigeria were characterized geochemically. The analytical results reveal that all crude oil samples are at the same stage of maturity and correspond to a vitrinite reflectance of about 0.8 % Ro. These oils show minor facies variations probably due to different terrestrial organic matter input indicated by their biomarker distributions. All biodegraded oil samples have similar facies pointing to the same oil with different ranks of biodegradation. The extent of biodegradation for the most degraded oils was from 1 to 4/5. The light hydrocarbon parameters distinguished unaltered from biodegraded oils. Biodegraded oils had higher initial saturations of solution gas, and therefore would lose more gas than black oils during evaporitic fractionation.

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Oleanane parameter: Verification by quantitative study of the biomarker occurrence in sediments of the Niger delta

Cited by 71 publications

References 7 publications

Organic Biogeochemistry of Detrital Flocculent Material (Floc) in a Subtropical, Coastal Wetland

Organic Biogeochemistry of Detrital Flocculent Material (Floc) in a Subtropical, Coastal Wetland

Geochemical characterization of Neogene sediments from onshore West Baram Delta Province, Sarawak: paleoenvironment, source input and thermal maturity

Geochemical characterization of crude oils from well ‘X’, Agbada formation, onshore Nigeria

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