Trace and rare earth element geochemistry of phosphate nodules from the lower Cambrian black shale sequence in the Mufu Mountain of Nanjing, Jiangsu province, China

Jiang, Shao‐Yong; Zhao, Hai-Xiang; Yongquan, Chen; Yang, Tao; Yang, Jin; Ling, Hong‐Fei

doi:10.1016/j.chemgeo.2007.07.010

Cited by 142 publications

(76 citation statements)

References 46 publications

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“…A few samples are bearing high Ba concentrations and positive Eu anomalies, which are distributed in JLW0.00-JLW0.85 and JLW2.75-JLW3.90. Ba/Sm ratios have fine correlations with Eu/Eu* ratios in these samples ( Figure 5), which indicates that high Ba concentrations would elevate Eu concentrations during analyzing in ICP-MS [35] . Consequently, positive Eu anomalies in these samples might be caused by analysis.…”

Section: Resultsmentioning

confidence: 90%

Trace element and rare earth element of cap carbonate in Ediacaran Doushantuo Formation in Yangtze Gorges

et al. 2009

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For the Doushantuo cap carbonate at the Jiulongwan section in the Yangtze Gorges, its concentrations of redox sensitive elements suggest two distinct enrichments in stratigraphy. These enrichments occur at about 0.8 m and 3.3 m above the bottom of cap carbonate, respectively. They are interpreted as the temporary anoxic depositional conditions due to the oxidation of seeped methane. REE+Y patterns of the cap carbonate are classified into three types with different styles: (1) from the bottom to 2.45 m, representing the behaviors of freshwater and suggesting that massive meltwater swarmed into surface oceans during the deglaciation; (2) from 2.45 m to 3.3 m, indicating the pattern of ancient seawater possibly due to upwelling of deep water; and (3) from 3.3 m to the top, showing "MREE bulge" pattern with HREE-depletion as a result of diagenesis. The three-stage REE+Y patterns represent the transformations of shallow water in the wake of the Marinoan glaciation in this region: the fresh meltwater was dominant first, and then it interfused into the oceanic basin by the transgression and upwelling. Bloom of plankton further introduced anoxia near the water-sediment interface. Doushantuo Formation, cap carbonate, trace element, REE, methane seep

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Section: Resultsmentioning

confidence: 90%

Trace element and rare earth element of cap carbonate in Ediacaran Doushantuo Formation in Yangtze Gorges

et al. 2009

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“…These ores contain levels of trace metal contaminants that vary over a wide range, depending on their geological origin and geographical location [1]. World phosphate resources are distributed approximately as follows, according to their type: 75% from sedimentary marine deposits; 15-20% from igneous, metamorphic, and weathered deposits; and 2-3% from biogenic sources, i.e., bird and bat guano accumulations [15,30]. Metal concentrations found in rock phosphate are variable, depending on their source of origin.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Effects of Phosphate Fertilizer Application on the Heavy Metal Content in Agricultural Soils with Different Cultivation Patterns

Cheraghi

Lorestani

Merrikhpour

2011

Biol Trace Elem Res

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The use of phosphate fertilizers is essential in agriculture, because they supply farmland with nutrients for growing plants. However, heavy metals might be included as impurities in natural materials and minerals, so heavy metals can also be present in phosphate fertilizers or other chemical fertilizers. The aim of this work was to assess the heavy metal content and contamination status of agricultural soils in the Hamadan province of Iran used for the cultivation of different crops, including cucumber, potatoes, and sugar beet. Surface soil samples were collected and analyzed to determine the total concentration of specific elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn), before the pollution index was calculated for each element. Soils used for the cultivation of the three types of crop were not contaminated with As, Cr, Cu, Pb, or Zn. However, the pollution indices for Cd were 1.1, 4.4, and 3.8 in cucumber, potato, and sugar beet fields, respectively, which indicated moderate, high, and high levels of contamination, respectively. Soils from potato and sugar beet fields were heavily contaminated with Cd, which may have resulted from long-term overuse of phosphate fertilizers.

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“…In general, these ratios correspond to high ratios of Ni/Co, V/Cr, U auth and V/Ni [22]. Most of the researches on these parameters involve estimating the redox state of mudstones (organic-rich black shales), but the approach is applicable to siliciclastic facies, carbonatic facies, and phosphorite as suggested by Tonger et al [23], Jiang et al [24] and Chang et al [25]. For stratigraphic variations in V/(V+Ni), the Ni/Co ratios are related to the alternate changes in the oxic and anoxic regimes of Ordovician carbonate sediment in Ordos Basin, which are coupled to the characteristics of the biostratigraphy and sedimentology [23].…”

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confidence: 98%

A new paleoenvironmental index for anoxic events—Mo isotopes in black shales from Upper Yangtze marine sediments

Zhou

Huang

et al. 2011

Sci. China Earth Sci.

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This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the Early Silurian at the Wangjiawan section in Yichang and the Late Permian Dalong Formation in the Shangsi Section of Sichuan. The applicability of different geochemical parameters used as paleo-oxygenation indices are also compared. The preliminary results show that V/(V+Ni), U auth (auth U), V/Cr, Ce anom and U/Th have a scattered variation range, but most samples plot within the suboxic-anoxic fields. The suboxic-anoxic environment was dominant during the deposition and formation of the two anoxic facies. These redox indicators show little correspondence to the δ 98 Mo values. The U/Mo ratio can be used as a potential proxy for the paleo-redox conditions due to the possibility that Mo is enriched relative to U at different redox gradients during early diagenesis. This evidence is more significant for the euxinicity condition and corresponds to positive δ 98 Mo (>1.5‰) values with low U/Mo ratios. This evidence is likely related to the depositional conditions near the boundary between anoxic and euxinic environments, which are characterised by low bioturbation or water circulation. Other samples reveal a wide scatter of U/Mo ratios and δ 98 Mo <1.5‰. These results are likely due to punctuated improvements in oxygenation with intense bioturbation or water circulation, which led to the redistribution of trace element. molybdenum isotopes, proxy for paleo-redox conditions, black shale, Upper Yangtze Citation: Zhou L, Su J, Huang J H, et al. A new paleoenvironmental index for anoxic events-Mo isotopes in black shales from Upper Yangtze marine sediments.The variations in the redox state of marine environments are determined by the distributions, activities, and evolution of marine organisms, and the uptake, transference, cycling and diffusion of dissolved trace elements from the water column across the sediment-water interface [1][2][3]. Since the apparent increase in the O 2 levels in the oceans from 1.0-0. 54 Ga[4], the ocean has experienced many global anoxic events [5][6][7]. The oxygen-depleted facies related to the anoxic events would not only result in the formation of metal reservoirs and reservoirs, but also controls for the generation, discharge, migration and preservation of petroleum reservoirs. Perhaps 80% of the world's petroleum has been generated from these ancient organic-rich sediments. Thus, the investigation of indicators related to paleo-redox conditions

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Trace and rare earth element geochemistry of phosphate nodules from the lower Cambrian black shale sequence in the Mufu Mountain of Nanjing, Jiangsu province, China

Cited by 142 publications

References 46 publications

Trace element and rare earth element of cap carbonate in Ediacaran Doushantuo Formation in Yangtze Gorges

Trace element and rare earth element of cap carbonate in Ediacaran Doushantuo Formation in Yangtze Gorges

Investigation of the Effects of Phosphate Fertilizer Application on the Heavy Metal Content in Agricultural Soils with Different Cultivation Patterns

A new paleoenvironmental index for anoxic events—Mo isotopes in black shales from Upper Yangtze marine sediments

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