Glauconite-bearing sedimentary phosphorites from the Tébessa region (eastern Algeria): Evidence of REE enrichment and geochemical constraints on their origin

Kechiched, Rabah; Laouar, Rabah; Bruguier, Olivier; Salmi-Laouar, Sihem; Kocsis, László; Bosch, Delphine; Foufou, Atif; Ameur-Zaimeche, Ouafi; Larit, Hamza

doi:10.1016/j.jafrearsci.2018.05.018

Cited by 48 publications

(24 citation statements)

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“…Broadly similar lithology defined by clays, marls, dolomite, and foraminiferal limestone hosts phosphorites in these basins. Phosphorites deposited in low palaeo-latitudes (< 30°) in Tunisia and Algeria (Kouwenhoven et al 1997;Messadi et al 2016;Garnit et al 2017;Kechiched et al 2018) (Fig. 3).…”

Section: Glauconite-phosphorite Associationmentioning

confidence: 99%

“…Phosphorite is a common associate of glauconite in the Paleogene (Glenn and Arthur 1990;Kouwenhoven et al 1997;Kechiched et al 2018;Metwally and Mahfouz 2018;Banerjee et al 2019). Conditions favourable for the precipitation of phosphorite and glauconite broadly overlap, requiring depletion in clastic supply and oxygen-depleted seawater.…”

Section: Factors Promoting Phosphorite Deposition During the Paleogenmentioning

confidence: 99%

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The formation of authigenic deposits during Paleogene warm climatic intervals: a review

et al. 2020

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Although Paleogene warm climatic intervals have received considerable attention for atmospheric and oceanographic changes, the authigenic mineralization associated with these time spans remains overlooked. An extensive review of the literature reveals a close correspondence between the high abundance of glauconite and warm climatic intervals during the Paleogene period. The abundance of phosphorite, ironstone, lignite and black shale deposits reveals similar trends. Although investigated thoroughly, the origin of these authigenic deposits is never understood in the background of Paleogene warming climatic intervals. A combination of factors like warm seawater, hypoxic shelf, low rate of sedimentation, and enhanced rate of continental weathering facilitated the glauconitization. The last factor caused the excess supply of nutrients, including Fe, Si, K, Mg and Al through the rivers, the cations needed for the formation of glauconite. The excessive inflow of nutrient-rich freshwater into the shallow seas further ensured high organic productivity and stratification in shallow shelves, causing hypoxia. The consequent rapid rise in sea-level during the warm periods created extensive low-relief shallow marine shelves starved in sediments. Oxygen-deficiency in the shallow marine environment facilitated the fixation of Fe into the glauconite structure. The inflow of nutrient-rich water during the warm climatic intervals facilitated the formation of phosphorite, ironstone, and organic-matter-rich sedimentary deposits as well. Although global factors primarily controlled the formation of these authigenic deposits, local factors played significant roles in some of the deposits. Therefore, phosphorites formed in marine conditions with open circulation within the tropical zone. While lush growth of rainforest covers in the tropical belt facilitated the formation of coastal lignite.

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Section: Glauconite-phosphorite Associationmentioning

confidence: 99%

Section: Factors Promoting Phosphorite Deposition During the Paleogenmentioning

confidence: 99%

The formation of authigenic deposits during Paleogene warm climatic intervals: a review

et al. 2020

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“…For the study of rare earth elements (REE), normalization was carried out with the PAAS [51], which is often used to study REE in sediments of rivers or lagoons [26,40,42,50,53,83]. Ce and Eu anomalies, respectively, Ce* and Eu* are calculated as follows.…”

Section: Calculation Of Ce and Eu Anomalies And (La/yb) N Ratio In Ramentioning

confidence: 99%

Geochemical Composition of the Lomé Lagoon Sediments, Togo: Seasonal and Spatial Variations of Major, Trace and Rare Earth Element Concentrations

Badassan

Avumadi

Ouro-Sama

et al. 2020

Water

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The concentrations of major, trace (TE), and rare earth (REE) elements and their seasonal and spatial distribution were studied on the fine fraction (<63 µm) of the sediments of the Lomé lagoons (West Lake, East Lake, and Lake Bè). The sediments were collected on a total of nine sampling sites (three per Lake) during two campaigns (dry season and rainy season). The quality of the sediments was assessed on the basis of the enrichment factor (EF) and the labile or non-residual fraction (NRF) in relation to the values recommended for the quality of the sediments (Sediment Quality Guidelines, SQG). The distribution of rare earth elements shows enrichments in light rare earths superior to those of heavy rare earth elements during any season. Positive Ce anomalies are less noticeable and less variable between seasons than Eu anomalies. La/Yb ratios are positively correlated with the percentage of Al and Fe oxides and with the percentage of fine fractions. The main bearing phases of rare earth elements are, therefore, Al and Fe oxides and the finest fractions of the sediments. The concentrations of trace elements vary little, according to the seasons, but show strong variations from one element to another. The degrees of enrichment obtained are moderate for Bi, Cr, Ga, Mo, Pb, Sn, and Zn (1.5 < EF < 5) to significant for As, Cd, and Sb (5 < EF < 20) for all sites of Lake Bè. For the sites of West Lake, the degrees of enrichment obtained are moderate for As, Cd, Cu, Mo, and Pb (1.5 < EF < 5) to a significance for As, Bi, Cd, Pb, Sb, Sn, and Zn (5 < EF < 20). Only the East Lake sites show high degrees of enrichment for elements such as Sb and Sn (20 < EF < 40). Trace elements (TE) such as As, Cd, Cu, and Ni have total concentrations within the range of variation of the SQG concentrations (particularly Probable Effect Level (PEL) and Effect Range Median (ERM)), whereas Cr, Pb, and Zn total concentrations are higher. The ranking of priority sites with respect to the sediment contamination is determined according to ERM and PEL quotients in relation to the probability of toxicity for benthic organisms. For almost all the sites, the priority is lowest to medium-low with regard to As, Cd, and Cu and medium-high (Cr and Ni) to highest (Pb and Zn), particularly for the East and West Lakes. Moreover, the NRF can represent significant percentages of the total TE concentrations: 5% to 15% for As, Bi, Ni, V, Mo, and Sc, 15% to 25% for Co, Cu, and Sr, 25% to 40% for Pb and Zn and, lastly, 47% to 55% for Cd.

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“…The Upper Creataceous-Eocene interval is among the significant phosphogenic periods known in the geological record (Pufahl and Groat, 2017). During this period, the Tethyan province saw the formation of large sedimentary phosphate deposits which are now exploited (Notholt 1985); e.g., in Algeria (Kechiched et al, 2018), Tunisia (Ounis et al, 2008), and Egypt (Baioumy et al, 2007). Contemporaneous phosphate deposits of Morocco correspond to the largest sedimentary phosphate reserve (70% of world-known reserves; Jasinski, 2018).…”

Section: Introductionmentioning

confidence: 99%

The Moroccan High Atlas phosphate-rich sediments: Unraveling the accumulation and differentiation processes

Bamiki

Séranne

Chellaı̈

et al. 2020

Sedimentary Geology

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The phosphate series of the Moroccan High Atlas accumulated during the Upper Cretaceous-Paleogene phosphogenic period, on a biologically-productive shallow-water platform. These phosphate-rich sediments were deposited during a relative sea-level cycle generating major stratigraphic surfaces. Five different types of phosphate lithofacies are recognized, based on their petrographic and sedimentologic features. The pristine phosphate lithofacies corresponds to phosphatic marls formed by francolite authigenesis within the outer platform domain below the storm wave-base (primary phosphogenesis zone). This primary phosphate lithofacies can be differentiated as a result of the interaction between hydrodynamic autocyclic processes and allocyclic forcing. Accordingly, the granular phosphate lithofacies was formed by in-situ storm and bottom currents that winnowed the pristine phosphate. This winnowed lithofacies, composed of densely-packed peloids, shows relatively high P2O5 concentrations. The turbiditic phosphate resulted from the basinward transport and deposition of other phosphate types by gravity flows leading to normally-graded phosphate sediment. The phosphatic lags were formed by wave reworking and transporting of pristine and associated granular facies within the inner platform. The karst-filling phosphate corresponds to former phosphate types transported by early transgressive currents and trapped within karstic pockets as microconglomeratic phosphate. The distribution of the different phosphate types across the margin and within the depositional sequences is controlled by the effects of relative sea-level changes. The pristine phosphate and associated winnowed facies are found above the major maximum flooding surface, which is dated by nannoflora to the Selandian-Thanetian transition. The phosphatic turbidites occurred during periods of high sea-level. The karst-related phosphatic facies 3 accumulated during early transgressive stages. The phosphatic lags accumulated mainly during the regressive phases of third and fourth order sequences. The accumulation processes of the different phosphate lithofacies control the ore grade of the phosphatic sediments: repeated storm-induced winnowing of pristine phosphate contributes to enrichment of the phosphate ore grade.

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Glauconite-bearing sedimentary phosphorites from the Tébessa region (eastern Algeria): Evidence of REE enrichment and geochemical constraints on their origin

Cited by 48 publications

References 50 publications

The formation of authigenic deposits during Paleogene warm climatic intervals: a review

The formation of authigenic deposits during Paleogene warm climatic intervals: a review

Geochemical Composition of the Lomé Lagoon Sediments, Togo: Seasonal and Spatial Variations of Major, Trace and Rare Earth Element Concentrations

The Moroccan High Atlas phosphate-rich sediments: Unraveling the accumulation and differentiation processes

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