Mo isotopes in the Lower Cambrian formation of southern China and its implications on paleo-ocean environment

Wen, Hao; Zhang, Yuxu; Fan, Haifeng; Hu, Ruizhong

doi:10.1007/s11434-009-0446-2

Cited by 18 publications

(6 citation statements)

References 29 publications

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“…Recently, Wen et al (2010) compared the isotopic composition of Mo standard solutions and proposed the NIST 3134 Mo solution as a new candidate for a reference material to report Mo isotopic composition of natural samples. On the other hand, Siebert et al (2003) proposed mean ocean water Mo (MOMO) as the reference for Mo isotopic composition.…”

Section: Synthesis Of Mo Isotopic Data In the Modern Oceanmentioning

confidence: 99%

The molybdenum isotopic composition of the modern ocean

et al. 2012

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Wang et al., 2011 (1) and is converted to δ 97/95 Mo by multiplying 0.67 when the system follows mass-dependent fractionation. Though no commonly-used Mo isotopic standard currently exists (see later), the standards used by different laboratories do appear to be isotopically similar at the level of 0.1-0.2‰. Continental rock samples, such as granite, basalt, and clastic sediments, have δ 98/95 Mo of ~0.1‰ Siebert et al., 2003). Ferromanganese oxides, which scavenge Mo from seawater in oxic conditions, have a light isotopic signature (δ 98/95 Mo = -1.0 to -0.5‰; Siebert et al., 2003), whereas sediments formed in euxinic conditions (aqueous H 2 S concentrations higher than ~11 µM, the action point pro-The molybdenum isotopic composition of the modern ocean (Received September 13, 2011; Accepted January 5, 2012) Natural variations in the isotopic composition of molybdenum (Mo) are showing increasing potential as a tool in geochemistry. Although the ocean is an important reservoir of Mo, data on the isotopic composition of Mo in seawater are scarce. We have recently developed a new method for the precise determination of Mo isotope ratios on the basis of preconcentration using a chelating resin and measurement by multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), which allows us to measure every stable Mo isotope . In this study, 172 seawater samples obtained from 9 stations in the Pacific, Atlantic, and Southern Oceans were analyzed, giving global coverage and the first full depth-profiles. The average isotope composition in δ Three-isotope plots for the Mo isotopes were fitted with straight lines whose slopes agreed with theoretical values for mass-dependent isotope fractionation. These results demonstrate that Mo isotopes are both uniformly distributed and follow a mass-dependent fractionation law in the modern oxic ocean. In addition, Mo isotopic analysis revealed that δ 98/95 Mo of the standard used in this study was 0.117 ± 0.009‰ lighter than the Mo standard that was used by Archer and Vance (2008). A common Mo standard is urgently required for the precise comparison of Mo isotopic compositions measured in different laboratories. On the other hand, our results strongly support the possibility of seawater as an international reference material for Mo isotopic composition.

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Section: Synthesis Of Mo Isotopic Data In the Modern Oceanmentioning

confidence: 99%

The molybdenum isotopic composition of the modern ocean

et al. 2012

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“…Arnold et al, 2004;Lehmann et al, 2007;Pearce et al, 2008;Wille et al, 2008;Gordon et al, 2009;Wen et al, 2009;Duan et al, 2010;Kendall et al, 2011;Zhou et al, 2012) under the assumption that in highly sulphidic conditions ('euxinic,' with >11 μmol/l H 2 S, Eriksson and Helz, 2000;Neubert et al, 2008), Mo is removed quantitatively from seawater into seafloor sediments. In these instances, the possible confounding influence of variable isotope fractionations imparted by non-quantitative Mo scavenging by sedimentary phases such Fe and Mn-oxides (Goldberg et al, 2009;Barling and Anbar, 2004;Siebert et al, 2003), and by conversion of Mo to thiomolybdates (MoO x S 2− 4−x ) under low-sulphide concentrations (e.g.…”

Section: Introductionmentioning

confidence: 99%

Continental margin molybdenum isotope signatures from the early Eocene

Dickson

Cohen

Coe

2014

Earth and Planetary Science Letters

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“…However, a number of scientific problems urgently need to be clarified for the Lower Cambrian strata in this region. Firstly, although several schemes for the placement of the Precambrian-Cambrian (PC/C) boundary in South China have been proposed by geologists, they have not reached a general consensus (Hsu et al 1985;Shen and Schidlowski 2000;Zhu et al 2001;Zhu et al 2003;Steiner et al 2007;Wille et al 2008;Zhou et al 2008;Jiang et al 2009;Li et al 2009;Wen et al 2009;Zhu et al 2009). Secondly, the regional correlation across different facies of the successions is still uncertain due to the scarce fossil records in the Lower Cambrian of the deep-water facies on the Yangtze Block, which hampers understanding of environmental changes of the paleo-ocean Chang et al 2012;Fan et al 2013).…”

Section: Introductionmentioning

confidence: 99%