Reply to Effect of concentration of organic matter on optical maturity parameters. Interlaboratory results of the organic matter concentration working group of the ICCP. Discussion by Vinay K. Sahay

Filho, João Graciano Mendonça; Araujo, Carla Viviane; Borrego, Ángeles G.; Cook, A. C.; Flores, Deolinda; Hackley, Paul C.; Hower, James C.; Kern, Marcio Luciano; Kommeren, K.; J, Kuś; Mastalerz, María; Mendonça, Joalice de Oliveira; Menezes, Taíssa Rêgo; Newman, J.; Ranasinghe, P.; Souza, Igor Viegas Alves Fernandes de; Suárez‐Ruíz, Isabel; Ujiié, Yoshihiro

doi:10.1016/j.coal.2011.01.001

Cited by 3 publications

(2 citation statements)

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“…This suggests that any lacustrine or marine phytoplankton contribution to the organic matter accumulation in the Mundeck Formation may probably be highly degraded in the water column and in the sediment. Furthermore, AOM can be phytoplankton, bacterial, or terrestrial derived (Ercegovac & Kostic, 2006; Mendonça Filho et al, 2011, 2012; Sawada, 2006; Tyson, 1995). Terrestrial‐derived AOM may not fluoresce (Ercegovac & Kostic, 2006; Sawada, 2006; Tyson, 1995).…”

Section: Discussionmentioning

confidence: 99%

Palaeoenvironment of the Albian‐Cenomanian Mundeck Formation in the Douala Basin (SW, Cameroon): Evidence from facies analysis and geochemistry

et al. 2023

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The Lower Cretaceous syn‐rift deposits of the Douala Basin (Mundeck Formation), located in the equatorial West African margin were investigated in order to determine the palaeoenvironment and organic matter source, redox conditions, palaeoclimate, and tectonic settings, based on facies, organic and inorganic geochemical analyses. The sediments consist of pebble, coarse, medium‐ to fine‐grained sandstone, siltstone, and grey to black fossiliferous shales. The shales are characterized by an average total organic carbon (TOC) of 1.02%, fair to poor source generative potential with present‐day hydrogen index values, which range from 31 to 350 mg HC/g TOC suggesting that the shale contains Type III kerogens with mainly gas generative potential. The organic particles are dominated by phytoclasts (40% on average) and non‐fluorescent amorphous organic matter (34% on average). The palynomorphs represent about 26% on average with a large amount of pollen grain and a minor amount of dinoflagellate cysts and microforaminifera test linings. The inferred depositional environment of the studied sediments is an alluvial fan to fluvio‐lacustrine with shallow marine incursion. This depositional environment received the contribution of aquatic algae and microorganisms with a large amount of terrestrial organic matter, evidenced by the presence of some dinoflagellate cysts and microforaminifera test linings, and relatively higher amounts of SiO2, Al2O3, and phytoclasts. The presence of trace elements such as Ba, Sr, V, Ni, Co and Cr in the analysed samples and their ratio, suggest suboxic to anoxic conditions of deposition with low salinity. The warm to cold and dry climatic conditions prevailed during the deposition of the Mundeck deposits and sediments from active continental margin setting during the lower Cretaceous periods in the Douala Basin as confirmed by inorganic geochemical data. This study sheds light on the early stage of the evolution of the Douala Basin which could be integrated into the context of a mid‐Jurassic to lower Cretaceous regional evolution of the opening of a passive margin. This evolution is characterized by an alluvial fan, fluviatile, lacustrine, lagoon and marine depositional system. This depositional system is recognized as part of the petroleum system recognized within the syn‐rift deposits in the others basins along the West African margin, where giant hydrocarbons have been discovered.

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Section: Discussionmentioning

confidence: 99%

Palaeoenvironment of the Albian‐Cenomanian Mundeck Formation in the Douala Basin (SW, Cameroon): Evidence from facies analysis and geochemistry

et al. 2023

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“…Nevertheless, the spectra of various species in sediments of the same age have been differentiated and significant differences have been found between Sphagnum spores and pollen grains of the same age in peats (van Gizel, 1967b). Other aspects, which affect the fluorescence spectra, are acid treatment during the preparation of the samples (van Gizel, 1967b;Mendonça Filho et al, 2010), environmental changes (Yeloff and Hunt, 2005) and differential alteration and corrosion of the grains (Havinga, 1967).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Spectral fluorescence variation of pollen and spores from recent peat-forming plants

Urbanczyk

Casado

Díaz

et al. 2014

International Journal of Coal Geology

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The fluorescence properties of spores and pollen grains examined under ultraviolet incident light are used to assess the maturity of sedimentary organic matter and may have other applications in relation to recent sediments, in areas such as palaeoenvironmental research. In this study pollen grains and spores from 33 species common in peat ecosystems were mounted on a glass slide in accordance with standard palynologycal procedures for recent plants. The main objective of this work was to assess the variability of fluorescence spectra of pollens and spores within a single species or even within a single sample. A minimum of 10 spectra were recorded from each sample and were averaged to obtain a spectrum characteristic of each sample. Both the average scattering and the scattering in different spectral regions were calculated using the standard deviation (SD) and the coefficient of variation (CV). The effect of the preparation techniques was assessed on some samples of Ericaceae taxa. The results indicated similar spectra for alcohol-washed and distilled water-washed samples, whereas the application of an acetolysis solution caused an increase in intensity and a shift to longer wavelengths. The spectra corresponding to the Sphagnum spores had the lowest intensity of all the families studied and displayed their maxima at the lowest registered wavelengths. They often showed a peak in the red region of the spectra, causing a larger scatter in fluorescence in this region. This peak is probably the result of wax or cytoplasmic material attached to the exospore. A significant number of Ericaceae taxa had two fluorescing pollen populations: a blue one of high intensity andsmaller size a yellow-orange one of low intensity and larger size. This difference could be related to different degrees of maturity of the pollen grains. In the case of pollen grains of herbaceous, tree and bush plants the largest scatter was found in the tails of the spectra towards the blue and red regions. The decreasing trend of fluorescence intensity with the shift of the spectra towards red was not observed in the pollen and spores of fresh plants. A good correlation was found between the spectral maxima ( max ) and the red-green quotient (Q R/G ) regardless of the type of plant.

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Review and update of the applications of organic petrology: Part 1, geological applications

Suárez‐Ruíz

Flores

Filho

et al. 2012

International Journal of Coal Geology

246

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Reply to Effect of concentration of organic matter on optical maturity parameters. Interlaboratory results of the organic matter concentration working group of the ICCP. Discussion by Vinay K. Sahay

Cited by 3 publications

References 10 publications

Palaeoenvironment of the Albian‐Cenomanian Mundeck Formation in the Douala Basin (SW, Cameroon): Evidence from facies analysis and geochemistry

Palaeoenvironment of the Albian‐Cenomanian Mundeck Formation in the Douala Basin (SW, Cameroon): Evidence from facies analysis and geochemistry

Spectral fluorescence variation of pollen and spores from recent peat-forming plants

Review and update of the applications of organic petrology: Part 1, geological applications

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