Molybdenum isotope behaviour accompanying weathering and riverine transport in a basaltic terrain

Pearce, Christopher R.; Burton, Kevin W.; Strandmann, Philip A.E. Pogge von; James, Rachael H.; Gíslason, Sigurður R.

doi:10.1016/j.epsl.2010.03.032

Cited by 101 publications

(104 citation statements)

References 43 publications

(79 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Non-conservative signatures have actually been observed for dissolved Mo concentrations in estuarine and coastal waters (Dellwig et al, 2007;Rahaman et al, 2010) and in the eastern tropical Pacific (Tuit and Ravizza, 2003). The non-conservative signatures also reported for δ 98/ 95 Mo in the low salinity zone of an estuary (Pearce et al, 2010a). Possible mechanisms for non-conservative behavior of dissolved Mo in oxic seawater are uptake by phytoplankton and cyanobacteria, remineralization from biogenic particles, adsorption to Mn-Fe (oxyhydr)oxides, and reductive release from Mn-Fe (oxyhydr)oxides.…”

Section: Homogeneity Of Mo Isotopes In the Modern Oxic Oceanmentioning

confidence: 64%

“…Although pioneering studies assumed that the Mo input from rivers to the ocean would have a Mo isotopic composition similar to continental rocks (δ 98/95 Mo ~ 0‰; Siebert et al, 2003), recent studies on river and estuarine water revealed great variations in the isotopic composition of dissolved Mo (δ 98/95 Mo = -0.1 to 2.3‰; Archer and Vance, 2008;Pearce et al, 2010a;Scheiderich et al, 2010;Neubert et al, 2011). Data on the hydrothermal input are scarce.…”

Section: Introductionmentioning

confidence: 99%

“…Data on the hydrothermal input are scarce. Low-temperature ridge-flank hydrothermal input is assumed to have an end-member value of δ 98/95 Mo ~ 0.8‰ based on observations at the Juan de Fuca Ridge (McManus et al, 2002), whereas an extremely light Mo (δ 98/95 Mo ~ -3.4‰) has been found in hydrothermal waters from Iceland (Pearce et al, 2010a).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The molybdenum isotopic composition of the modern ocean

et al. 2012

View full text Add to dashboard Cite

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.

show abstract

Section: Homogeneity Of Mo Isotopes In the Modern Oxic Oceanmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The molybdenum isotopic composition of the modern ocean

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The W/Ta ratio vs. depth in the Chhindwara profile is illustrated in Figure 4a For instance, at present, it is known that river waters are variably enriched in the heavier isotopes of Mo relative to igneous rocks and at least some of this fractionation is caused by preferential retention of lighter Mo isotopes in soils, in tandem with catchment geology variation and riverine Mo removal (Archer and Vance, 2008;Pearce et al, 2010;Neubert et al, 2011;Voegelin et al, 2012).…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

A combined Y/Ho, high field strength element (HFSE) and Nd isotope perspective on basalt weathering, Deccan Traps, India

et al. 2015

View full text Add to dashboard Cite

Please cite this article as: Babechuk, M.G., Widdowson, M., Murphy, M., Kamber, B.S., A combined Y/Ho, high field strength element (HFSE) and Nd isotope perspective on basalt weathering, Deccan Traps, India, Chemical Geology (2014), doi: 10.1016/j.chemgeo.2014 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. The chemical fingerprints of dust were identified in a paleo-flow top of the saprolite profile, A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTsuggesting that dust accumulation occurred during periods of quiescence between basaltic eruptions. During protracted exposure and laterite development, the magnitude to which dust overprints the basalt chemistry increases substantially as evident from much less radiogenic Nd isotope ratios and higher Th/Nb ratios in the Bidar profile relative to the protolith basalt. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTAttempts at quantifying the magnitude of dust accumulation in the laterite based on Th enrichment indicate a mass fraction of greater than 0.5 when the dust is assumed to have the chemistry of average upper continental crust. Although mixing models between the basalt and assumed dust composition cannot unambiguously constrain the dust source, the Nd isotope mixture preserved in the laterite points to a relatively young crustal dust source (e.g., similar to loess in composition) rather than the Precambrian shield rocks in the vicinity of the

show abstract

“…Today, seawater carries a homogeneous isotope composition of δ 98 Mo = 2.3±0.1‰ [4][5][6] relative to the oceanic input of dissolved Mo in rivers (90%) at ~0.7‰ [7][8][9]) with the rest from low temperature hydrothermal fluids [10] at ~0.8‰ [11].…”

Section: A1: Modern Mo Cyclementioning

confidence: 99%