Accurate and precise determination of Li isotopic compositions by multi-collector sector ICP-MS

Tomascak, Paul B.; Carlson, Richard W.; Shirey, Steven B.

doi:10.1016/s0009-2541(99)00022-4

Cited by 157 publications

(176 citation statements)

References 19 publications

Supporting

Mentioning

168

Contrasting

Order By: Relevance

“…The main sinks are secondary mineral formation during alteration of the oceanic crust and the incorporation of Li into marine sediments (Chan & Edmond, 1988;Chan et al, 2006;1992;Hathorne & James, 2006;Stoffyn-Egli & MacKenzie, 1984). The isotopic ratio of Li in modern oceans is ~31‰ (Tomascak et al, 1999). The continental crust has an average lithium-isotope composition of 0 ± 3‰ (Teng et al, 2004), whereas mid-ocean-ridge basalts usually have isotopic values of 3-5‰ (Elliott et al, 2006;Tomascak et al, 2008Tomascak et al, , 1999.…”

Section: Weathering and The Li-isotope Composition Of The Oceansmentioning

confidence: 99%

“…The isotopic ratio of Li in modern oceans is ~31‰ (Tomascak et al, 1999). The continental crust has an average lithium-isotope composition of 0 ± 3‰ (Teng et al, 2004), whereas mid-ocean-ridge basalts usually have isotopic values of 3-5‰ (Elliott et al, 2006;Tomascak et al, 2008Tomascak et al, , 1999. The difference of the isotopic ratio between the ocean water and continental and marine silicates is a function of high-and low-temperature alteration of these minerals.…”

Section: Weathering and The Li-isotope Composition Of The Oceansmentioning

confidence: 99%

See 1 more Smart Citation

Lithium-isotope evidence for enhanced silicate weathering during OAE 1a (Early Aptian Selli event)

Lechler

Strandmann

Jenkyns

et al. 2015

Earth and Planetary Science Letters

100

View full text Add to dashboard Cite

An abrupt rise in temperature, forced by a massive input of CO 2 into the atmosphere, is commonly invoked as the main trigger for Oceanic Anoxic Events (OAEs). Global warming initiated a cascade of palaeoenvironmental perturbations starting with increased continental weathering and an accelerated hydrological cycle that delivered higher loads of nutrients to coastal areas, stimulating biological productivity.The end-result was widespread anoxia and deposition of black shales: the hallmarks of OAEs. In order to assess the role of weathering as both an OAE initiator and terminator (via CO 2 sequestration) during the Early Aptian OAE 1a (Selli Event, ~120 Ma) the isotopic ratio of lithium isotopes was analysed in three sections of shallowmarine carbonates from the Pacific and Tethyan realm and one basinal pelagic section from the Tethyan domain. Because the isotopic composition of lithium in seawater is largely controlled by continental silicate weathering and high-and lowtemperature alteration of basaltic material, a shift to lighter  7 Li values is expected to characterize OAEs. The studied sections illustrate this phenomenon:  7 Li values decrease to a minimum coincident with the negative carbon-isotope excursion that effectively records the onset of OAE 1a. A second negative  7 Li excursion occurs coeval with the minimum in strontium isotopes after the event. The striking similarity to the strontium-isotope record argues for a common driver. The formation and destruction (weathering) of an oceanic LIP could account for the parallel trend in both isotope systems. The double-spike in lithium isotopes is probably related to a change in weathering congruencies. Such a chemostratigraphy is consistent with the hypothesis that an increase in silicate weathering, in conjunction with organic-carbon burial, led to drawdown of atmospheric CO 2 during the early Aptian OAE 1a.

show abstract

Section: Weathering and The Li-isotope Composition Of The Oceansmentioning

confidence: 99%

Section: Weathering and The Li-isotope Composition Of The Oceansmentioning

confidence: 99%

Lithium-isotope evidence for enhanced silicate weathering during OAE 1a (Early Aptian Selli event)

Lechler

Strandmann

Jenkyns

et al. 2015

Earth and Planetary Science Letters

100

View full text Add to dashboard Cite

show abstract

“…In addition, the large mass difference 2002). This study uses a recently developed multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) method that allows rapid and accurate lithium isotopic determinations on Li-poor mantle-derived samples (Tomascak et al, 1999a;.…”

Section: Introductionmentioning

confidence: 99%

“…Zack et al (2003) documented for the first time that distinct reservoirs with an isotopically light Li signature (δ 7 Li << ±0‰) exist in the Earth (Fig. 1, e.g., Chan and Edmond, 1988;Chan et al, 1992Chan et al, , 1994Chan et al, , 1999Chan et al, , 2002bYou and Chan, 1996;Huh et al, 1998Huh et al, , 2001Moriguti and Nakamura, 1998a, b;Zhang et al, 1998;Tomascak et al, 1999aTomascak et al, , 2000Tomascak et al, , 2002Chan and Kastner, 2000;James and Palmer, 2000;.…”

Section: Introductionmentioning

confidence: 99%

“…The δ 7 Li value of Li in dehydrated fluid should be higher than that in the residual slab Li (Zack et al, 2003). During low-temperature alteration at the seafloor, the δ 7 Li values of altered mid-ocean ridge basalts (MORBs) tend to increase with the degree of alteration, but those of (Chan et al, 1992;Moriguti and Nakamura, 1998a), arc lavas (Moriguti and Nakamura, 1998a;Tomascak et al, 2000Tomascak et al, , 2002Chan et al, 2002b), oceanic sediments (Chan et al, 1994;Zhang et al, 1998;Chan et al, 1999;Chan and Kastner, 2000), river water (Huh et al, 1998(Huh et al, , 2001, seawater (Chan and Edmond, 1988;You and Chan, 1996;Moriguti and Nakamura, 1998b;Tomascak et al, 1999a;James and Palmer, 2000;Pistiner and Henderson, 2003), mantle-derived xenolith (clinopyroxene data) (Nishio et al, 2004), eclogite (whole-rock data) (Zack et al, 2003). The data for the altered oceanic crust consist of those of low-temperature altered basalts (Chan et al, 1992(Chan et al, , 2002b, high-temperature altered basalts (Chan et al, 2002b), and serpentinized abyssal peridotite (whole-rock data) (Decitre et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Lithium, strontium, and neodymium isotopic compositions of oceanic island basalts in the Polynesian region: constraints on a Polynesian HIMU origin

et al. 2005

View full text Add to dashboard Cite

To investigate the origin of the HIMU (high-µ) reservoir in the mantle, we measured Li, Sr, and Nd isotopic compositions of several oceanic island basalts (OIBs) from the Polynesian region. We used a recently developed multiple-collector inductively coupled plasma mass spectrometry method that allows precise and accurate Li isotopic determinations. This study presents the first Li isotopic data on HIMU OIBs. Li] L-SVEC standard -1] × 1000) of the Polynesian HIMU OIBs (Mangaia, Tubuai, and Rurutu) range from +5.0‰ to +7.4‰, which are higher than those of fresh normal mid-ocean ridge basalt (N-MORB) glasses (ca. +3‰). The simultaneously measured K/Rb, Ba/Rb, and 87 Sr/ 86 Sr ratios indicate that the analyzed HIMU OIBs are free from significant posteruption alteration. These results suggest that the δ 7 Li value of the Polynesian HIMU source is never lower than those of the N-MORBs.Among the numerous models for the origin of the HIMU source, the most widely accepted model is that it involves subducted (dehydrated) oceanic crust. For this HIMU-origin model, our new Li isotopic results exclude the highly altered portion, that is, the uppermost part of the oceanic crust, because the δ 7 Li value of subducted highly altered MORB should be extremely low (δ 7 Li < fresh MORB). For these reasons, we propose that the Polynesian HIMU source is the relatively less-altered oceanic crust underlying the highly altered crust. Whereas Pb, Sr, and Nd isotopic signatures dominantly indicate the involvement of sediments in a source, the Li isotopic signature is more sensitive to the degree of alteration experienced by the basaltic crust and thus can be used to distinguish what part of the crust was trapped in the OIB magma. It therefore provides information complementary to that provided by the radiogenic isotopes.

show abstract

Light Stable Isotopic Compositions of Enriched Mantle Sources: Resolving the Dehydration Paradox

Dixon

Bindeman

Kingsley

et al. 2017

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Volatile and stable isotope data provide tests of mantle processes that give rise to mantle heterogeneity. New data on enriched mid‐oceanic ridge basalts (MORB) show a diversity of enriched components. Pacific PREMA‐type basalts (H2O/Ce = 215 ± 30, δDSMOW = −45 ± 5 ‰) are similar to those in the northern Atlantic (H2O/Ce = 220 ± 30; δDSMOW = −30 to −40 ‰). Basalts with EM‐type signatures have regionally variable volatile compositions. Northern Atlantic EM‐type basalts are wetter (H2O/Ce = 330 ± 30) and have isotopically heavier hydrogen (δDSMOW = −57 ± 5 ‰) than northern Atlantic MORB. Southern Atlantic EM‐type basalts are damp (H2O/Ce = 120 ± 10) with intermediate δDSMOW (−68 ± 2 ‰), similar to δDSMOW for Pacific MORB. Northern Pacific EM‐type basalts are dry (H2O/Ce = 110 ± 20) and isotopically light (δDSMOW = −94 ± 3 ‰). A multistage metasomatic and melting model accounts for the origin of the enriched components by extending the subduction factory concept down through the mantle transition zone, with slab temperature a key variable. Volatiles and their stable isotopes are decoupled from lithophile elements, reflecting primary dehydration of the slab followed by secondary rehydration, infiltration, and re‐equilibration by fluids derived from dehydrating subcrustal hydrous phases (e.g., antigorite) in cooler, deeper parts of the slab. Enriched mantle sources form by addition of <1% carbonated eclogite ± sediment‐derived C‐O‐H‐Cl fluids to depleted mantle at 180–280 km (EM) or within the transition zone (PREMA).

show abstract

Accurate and precise determination of Li isotopic compositions by multi-collector sector ICP-MS

Cited by 157 publications

References 19 publications

Lithium-isotope evidence for enhanced silicate weathering during OAE 1a (Early Aptian Selli event)

Lithium-isotope evidence for enhanced silicate weathering during OAE 1a (Early Aptian Selli event)

Lithium, strontium, and neodymium isotopic compositions of oceanic island basalts in the Polynesian region: constraints on a Polynesian HIMU origin

Light Stable Isotopic Compositions of Enriched Mantle Sources: Resolving the Dehydration Paradox

Contact Info

Product

Resources

About