Geochemistry and mineralogy of sediments from the Ventersdorp and Transvaal Supergroups, South Africa: Cratonic evolution during the early Proterozoic

Wronkiewicz, David J.; Condie, Kent C.

doi:10.1016/0016-7037(90)90323-d

Cited by 236 publications

(68 citation statements)

References 34 publications

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“…Some relatively immobile elements like Sc, Th, Zr, Hf and rare earth elements (REE) show very low concentrations in natural waters and are transported almost quantitatively throughout the sedimentary process from parent rocks to clastic sed-iments [4,14]. The relative distribution or enrichment of these immobile elements in felsic and basic rocks have been used to infer the relative contribution of felsic and basic sources in shales from different tectonic environments [15]. For example, La and Th are enriched in felsic rocks, whereas Sc, Cr, and Co are more concentrated in basic rocks relative to felsic rocks.…”

Section: Introductionmentioning

confidence: 99%

Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting

2017

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Geochemical compositions of twenty-four sandstone and shale samples from the Ecca Group were analysed to decipher their provenance, paleoweathering conditions and tectonic setting. The shales have high Fe 2 O 3 , K 2 O, TiO 2 , Ce, Cu, Ga, La, Nb, Nd, Rb, Sc, Sr, Th and Y content more than the sandstones, whereas, sandstones are higher in SiO 2 , Hf and Zr than the shales. The positive correlations of Al 2 O 3 with other elements as well as the abundance of Ba, Ce, Th, Rb, Zn and Zr suggest that these elements are primarily controlled by the dominant clay minerals. Tectonic discrimination diagrams revealed that the sandstones and shales are mostly of quartzose sedimentary provenance, suggesting that they were derived from a cratonic interior or recycled orogen. The binary plots of TiO 2 versus Ni, TiO 2 against Zr and La/Th versus Hf as well as the ternary diagrams of V-Ni-Th*10 indicate that the shales and sandstones were derived from felsic igneous rocks. A-CN-K (Al 2 O 3 -CaO-K 2 O) ternary diagram and indices of weathering (CIA, CIW and PIS) suggest that the granitic source rocks underwent moderate to high degree of chemical weathering. The CIA values range between 24.41% and 83.76%, indicating low to high weathering conditions. The CIW values for the studied sandstones and shales range from 25.90 to 96.25%, suggesting moderate to high intensive chemical weathering. ICV values for the sandstones and shales vary from 0.71 to 3.6 (averaging 1.20) and 0.41 to 1.05 (averaging 0.82), respectively. The K 2 O/Na 2 O ratios for the studied samples vary from 0.71 to 8.29, which reveal moderate to high maturity. The plot of CIA against ICV shows that most of the shales are geochemically mature and were derived from both weak and intensively weathered source rocks. The tectonic setting discrimination diagrams support passive-active continental margin setting of the provenance.

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Section: Introductionmentioning

confidence: 99%

Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting

2017

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“…Many reports have been published in which the distribution and abundance of REEs are studied from a geochemical or mineralogical viewpoints (Scott, 1990;Wronkiewicz and Condie, 1990;Liu et al, 1993). On the other hand, literature information on the environmental eects, bioaccumulation and bioavailability of REEs has received scant attention until very recent years.…”

Section: Introductionmentioning

confidence: 99%

Speciation of rare earth elements in soil and accumulation by wheat with rare earth fertilizer application

Zhang

Shan

2001

Environmental Pollution

177

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apsule'': Rare earth elements increased wheat yields and accumulated in plants in relation to concentrations in fertilizers. AbstractA greenhouse study was conducted to investigate the accumulation of rare earth elements (REEs), La, Ce, Pr and Nd, in winter wheat (Triticum aestivum L.), and the speciation of these elements in soil following the application of REE-based fertilizers. Improved crop yield was con®rmed by the experiment. The accumulation behavior of La, Ce, Pr and Nd in wheat varied depending on the concentration of REE fertilizer application, i.e. increased with increasing REE concentration at low fertilization application, constant over the medium REE range, and decreased with increasing REE concentration at high fertilizer application. Signi®cant negative correlation was obtained between REE contents in roots and soil pH (r=À0.5787 to À0.8442 for La). REEs in both the fertilized and unfertilized soils were fractionated by a three-stage sequential extraction procedure into three chemically distinct fractions: water soluble, exchangeable and carbonate bound (B1), Fe±Mn oxide bound (B2), and organic and sul®de bound (B3). REEs in fertilized soils were found mainly in the B2 and B3 fractions, with only a small amount in the B1 fraction. REEs in B1 and B2 fractions were negatively correlated with soil pH (r=À0.6892 to À0.8927 and À0.7462 to À0.9482). Signi®cant correlation was obtained between REEs in B1 fraction and REE contents in root. The correlation coecients ranged from 0.6159 to 0.7410 when fertilizer application was lower than 20.0 mg/kg soil. No acceptable relationship was observed between REE contents in shoot and any of the extractable fractions in soils. #

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“…provenance composition (Wronkiewicz and Condie, 1990;Cox et al, 1995;Cullers, 1995). The extent to which these elemental ratios are useful in unraveling the provenance of terrigenous materials present in the carbonate rock is clearly addressed by Cullers (2002).…”

Section: Possible Source Of Rees In the Alisitos Formationmentioning

confidence: 99%

Untitled

2017

Rev. Mex. Cien. Geol.

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Petrography, stable carbon and oxygen isotopes, and major, trace, and rare earth elements geochemistry of limestones of the Alisitos Formation in the Los Torotes, Baja California were studied in order to document the elemental variations among Member C (MC) and Member E (ME) of the formation and to understand their diagenetic and depositional conditions. The major petrographic types identified are mudstone, wackestone and packstone. The limestones of the Alisitos Formation show significant variations in δ 13 C and δ 18O values (+4.13 to +5.26‰; -14.17 to -6.84‰; respectively). The limestones from Member C (MC) show higher ΣREE content (23 ± 17, n=10) than Member E (ME) (11 ± 5.5, n=9) of the Alisitos Formation. The observed variations in ΣREE content in these limestones are due to the amount of detrital material present in them. The limestones from ME record seawater-like REE+Y patterns, whereas the MC records non-seawater-like signatures (i.e. significant enrichment of middle rare earth elements: MREE). Most of the analyzed samples from the Alisitos Formation show negative Ce anomalies (Ce/Ce*: 0.67 -0.99, n=17). The limestones show both negative and positive Eu anomalies (Eu/Eu*: 0.58 -2.91, n=19). The positive Eu anomalies identified in many samples may be due to the influence of hydrothermal fluids or co-precipitation of hydrothermal Fe-sulfide. The limestones of ME exhibit seawater-like-REE patterns suggesting that most of the REEs present in them were derived from seawater. However, the limestones of MC were contaminated by detrital materials which effectively mask the seawater-like signatures. The detrital materials present in the limestones of MC were probably derived from the mafic to felsic source rocks.

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Geochemistry and mineralogy of sediments from the Ventersdorp and Transvaal Supergroups, South Africa: Cratonic evolution during the early Proterozoic

Cited by 236 publications

References 34 publications

Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting

Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting

Speciation of rare earth elements in soil and accumulation by wheat with rare earth fertilizer application

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