Decrypting geochemical signatures in subsurface Niger delta sediments: Implication for provenance, weathering, and paleo-environmental conditions

Overare, Brume; Azmy, Karem; Garzanti, Eduardo; Osokpor, Jerry; Ogbe, Ovie B.; Avwenagha, E.O.

doi:10.1016/j.marpetgeo.2020.104879

Cited by 15 publications

(6 citation statements)

References 104 publications

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“…Two classical geochemical indicators (Rb/Sr and V/Cr ratios) were used to elucidate the paleo-geomorphic and depositional patterns in the two areas. Higher Rb/Sr and V/Cr ratios reflect more intensive weathering and more reducing environments, respectively. , It can be found that the Rb/Sr and V/Cr ratios in the depth-matched sediments were generally higher in the paleo-channel area (average Rb/Sr: 1.617 and average V/Cr: 1.614) than those in the paleo-interfluve area (average Rb/Sr: 1.052 and average V/Cr: 1.360) (Figure ), suggesting that more intensive catchment weathering occurred in the paleo-channel area during the last deglaciation, under a warmer climate. Also, rapid sedimentation then produced a more reducing environment for the depth-matched sediments in the paleo-channel area.…”

Section: Resultsmentioning

confidence: 99%

Paleo-Geomorphology Determines Spatial Variability of Geogenic Ammonium Concentration in Quaternary Aquifers

Deng

Liu

et al. 2023

Environ. Sci. Technol.

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Naturally occurring (i.e., geogenic) ammonium in groundwater has been widely detected globally, but the major controls on its regional distribution have been poorly characterized. Here, we identified the dominant role of paleo-geomorphology driven by paleo-climate in controlling the spatial variability of geogenic ammonium in groundwater using random forest algorithm and revealed the underlying mechanisms based on borehole sediment analysis of data obtained from the Dongting Lake Plain of the central Yangtze River basins in China. In the paleochannel (PC) area, the aquifer depth-matched sediments were deposited during the last deglaciation when warm climate resulted in rapid filling into incised valleys, and terrestrial organic matter (OM) mainly as lignin experienced less degradation prior to sedimentation and had lower humification, higher N abundance, and nominal oxidation state of carbon (NOSC). In the paleo-interfluve (PI) area, the depth-matched sediments were deposited during the last glaciation, followed by intensive erosion in the surface during the last glacial maximum, and terrestrial OM mainly as lignin had been partly degraded into aliphatics prior to sedimentation and had higher humification, lower N abundance, and NOSC. As a result, under the present anaerobic conditions, less-humic and N-rich OM with more oxidized C tends to be more intensively mineralized into ammonium in the PC area than those in the PI area. These findings highlight the importance of paleo-geomorphology with paleo-climate in controlling the enrichment of geogenic ammonium in groundwater, which has a universal significance for understanding the genesis and distribution of high N loads in the aquatic environment worldwide.

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Section: Resultsmentioning

confidence: 99%

Paleo-Geomorphology Determines Spatial Variability of Geogenic Ammonium Concentration in Quaternary Aquifers

Deng

Liu

et al. 2023

Environ. Sci. Technol.

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“…The intensity of weathering of siliciclastic fractions in sediments was estimated by calculating the chemical index of alteration (CIA) as per Nesbitt and Young (1982) and plagioclase index of alteration (PIA) as per Fedo et al (1995). CaO in the siliciclastic fraction was estimated using the methods of McLennan et al (1993), Bock et al (1998), Nagarajan et al (2017) and Overarea et al (2021). CaO was used for further calculation when it is less or equal to Na 2 O.…”

Section: Methodsmentioning

confidence: 99%

“…as per Fedo et al (1995). CaO in the siliciclastic fraction was estimated using the methods of McLennan et al (1993), Bock et al (1998), Nagarajan et al (2017) and Overarea et al (2021). CaO was used for further calculation when it is less or equal to Na 2 O.…”

Section: Geochemistrymentioning

confidence: 99%

Tectono‐climatic and depositional environmental controls on the Neolithic habitation sites, Vaigai River Basin, Southern India

Ramkumar,

Nagarajan,

Juni

et al. 2024

Geological Journal

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The establishment, development and abandonment and/or destruction of ancient civilizations were catalytically controlled by geomorphic features such as lakes and rivers and the climate. This paper examined the possible influence of tectonism and climate on six habitations of the ancient Vaigai River Basin civilization in South India, using multiple proxies such as grain size, geochronology and geochemistry of the sedimentary archives. The tectonic setting of the basin changed between the active margin and passive margin; the discriminant diagrams suggested varying provenance and changing climatic conditions over the mid‐ and‐late Holocene. Tectonic activism and quiescence, base‐level change in the channel morphology led to the burial/marooning of the first habitation surface. Overall, arid conditions were punctuated with catastrophic flooding and peak discharge (flood) destroyed the second, third and fourth habitation sites. These flooding events were characterized by moderate weathering (CIA) and high values of Al, Fe and Rb/Sr and low Ca/Mg in the sediment records. The abandonment/destruction of the fifth habitation also occurred during an arid interval (droughts), possibly caused by weak monsoon. Along with the interactions between tectono‐climatic and fluvial geomorphic factors, the new results provided avenues to (a) check and recognize the archives for 8.2 and 4.2 ka‐like events in this part of the world, and (b) the utility of integrated analyses to constrain on the civilizational histories of the mankind.

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“…The concentration and distribution of trace elements in the sedimentary rocks tend to vary considerably with the medium conditions, and their geochemical behaviour is controlled by the relevant minerals (Krauskopf & Bird, 1967). Therefore, the content and distribution of trace elements and their ratios to similar elements can reveal further information about the geological evolution of a sedimentary basin (Cullers, 2002; McLennan, Hemming, McDaniel, & Hanson, 1993; Overare et al, 2021; Taylor & McLennan, 1985). In siliciclastic sedimentary rocks, most trace elements are found in high concentrations in the clay fraction and are dominated by the clay minerals in fine‐grained sediments (Lopez, Bauluz, Fernández‐Nieto, & Oliete, 2005).…”

Section: Introductionmentioning

confidence: 99%

Geochemical characteristics and the significance of two major coal‐bearing strata claystones from the Datong Coalfield (North China)

Liu

Zhang

et al. 2022

Geological Journal

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This study aims to investigate the significance of the geochemical differences and the factors that control the geochemistry of two major types of coal‐bearing stratum claystones (sedimentary kaolinitic claystone [SK‐claystone] and tonstein). The SK‐claystone and tonstein derived from the Taiyuan Formation of the Upper Carboniferous coal‐bearing strata in the Datong Coalfield of North China have been comprehensively analysed using X‐ray powder diffractometer, scanning electron microscopy, X‐ray fluorescence, and inductively coupled plasma mass spectrometry. The results showed that the SK‐claystones and tonsteins exhibit similar SiO2 content; however, the content of Al2O3 in tonsteins is higher than that in SK‐claystones, whereas the TFe2O3 and K2O content in tonsteins are lower than those in SK‐claystones. These findings are consistent with the mineral composition analysis of the samples. The SK‐claystones and tonsteins have different parent rocks, as shown by the Al2O3/TiO2 ratios, diagram of Zr/TiO2 versus Nb/Y, and chondrite‐normalized rare earth element patterns. The palaeosalinity indexes (B/Ga and Sr/Ba) and palaeoredox proxies (Mo and U enrichment factors as well as U/Th ratios) indicate that both SK‐claystones and tonsteins were formed in freshwater suboxic–oxic environments. The kaolinite in SK‐claystones and tonsteins is formed via the deposition or crystallization of aluminium‐rich weathering products and alteration of volcanic ash, respectively. In summary, the different parent rocks and diagenetic processes are the main factors differentiating the geochemical characteristics of the two types of claystones. Our study links the different types of elemental enrichment features to the geological genesis of the two types of claystones, indicating that the trace elemental enrichment characteristics can be used as indicators for distinguishing the SK‐claystone and tonstein in the Datong Coalfield as well as other similar coalfields.

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Decrypting geochemical signatures in subsurface Niger delta sediments: Implication for provenance, weathering, and paleo-environmental conditions

Cited by 15 publications

References 104 publications

Paleo-Geomorphology Determines Spatial Variability of Geogenic Ammonium Concentration in Quaternary Aquifers

Paleo-Geomorphology Determines Spatial Variability of Geogenic Ammonium Concentration in Quaternary Aquifers

Tectono‐climatic and depositional environmental controls on the Neolithic habitation sites, Vaigai River Basin, Southern India

Geochemical characteristics and the significance of two major coal‐bearing strata claystones from the Datong Coalfield (North China)

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