Manganese–chromium isotope systematics of carbonaceous chondrites

Shukolyukov, A.; Lugmair, G. W.

doi:10.1016/j.epsl.2006.07.036

Cited by 148 publications

(212 citation statements)

References 28 publications

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“…At the bulk rock scale, carbonaceous chondrites exhibit 53 Cr and 54 Cr excesses (e.g., Trinquier et al 2007 (Moynier et al 2007;Shukolyukov & Lugmair 2006). These initial ratios are consistent with the best estimate initial ratio of the solar system ( 53 Mn/ 55 Mn ratio = (9.7 ± 1.1) × 10 −6 ) …”

Section: Introductionsupporting

confidence: 69%

“…Nevertheless, the elemental 55 Mn/ 52 Cr ratio in the present data set is twice as high as in Yamashita et al (2005) and most probably is at the origin of the elevated 53 Cr/ 52 Cr of the bulk rock reflecting the past presence of 53 Mn. Figure 6 presents the linear correlation between the bulk rock ε 53 Cr values and elemental 55 Mn/ 52 Cr ratios for different carbonaceous chondrites (Moynier et al 2007;Shukolyukov & Lugmair 2006;Trinquier et al 2008b). Our Tagish lake value deviates somehow from the internal bulk 53 Mn-53 Cr carbonaceous chondrite isochron (Moynier et al 2007;Shukolyukov & Lugmair 2006;Trinquier et al 2008b).…”

Section: Heterogeneity At a Whole Rock Scale: Tagish Lakementioning

confidence: 99%

“…Figure 6 presents the linear correlation between the bulk rock ε 53 Cr values and elemental 55 Mn/ 52 Cr ratios for different carbonaceous chondrites (Moynier et al 2007;Shukolyukov & Lugmair 2006;Trinquier et al 2008b). Our Tagish lake value deviates somehow from the internal bulk 53 Mn-53 Cr carbonaceous chondrite isochron (Moynier et al 2007;Shukolyukov & Lugmair 2006;Trinquier et al 2008b). However, since it presents the highest Mn/Cr ratio ever measured for a bulk meteorite, it contributes to better constrain the slope of this isochron.…”

Section: Heterogeneity At a Whole Rock Scale: Tagish Lakementioning

confidence: 99%

“…The 53 Cr systematics is well suited to date the relative timescales of parent-body processes (e.g., Shukolyukov & Lugmair 2006;Trinquier et al 2008b) or the time of formation of single crystal grains (e.g., Petitat et al 2011). 54 Cr anomalies have been detected in presolar grains (Zinner 2005) and refractory inclusions (Birck & Allègre 1984;Papanastassiou 1986).…”

Section: Introductionmentioning

confidence: 99%

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The Chromium Isotopic Composition of the Ungrouped Carbonaceous Chondrite Tagish Lake

Petitat

Birck

Luu

et al. 2011

ApJ

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Early solar materials bear a variety of isotopic anomalies that reflect compositional differences deriving from distinct stellar nucleosynthetic processes. As shown in previous studies, the stepwise dissolution with increasing acid strengths of bulk rock carbonaceous chondrites liberates Cr with both excesses and deficits in 53 Cr and 54 Cr relative to the terrestrial standard. The magnitude of the 54 Cr variations within a meteorite decreases in the sequence CI1 > CR2 > CM2 > CV3 > CO3 > CK4 and correlates with the degree of metamorphism of each carbonaceous chondrite class. This study shows that the Tagish Lake meteorite presents the highest excesses in 54 Cr ever measured in a bulk silicate phase. According to this study, the Tagish Lake meteorite is composed of the least re-equilibrated material known at this time. The magnitude of 54 Cr variation decreases now in the following sequence: Tagish Lake (ungrouped CI2) > Orgueil (CI1) > Murchison (CM2) > Allende (CV2). Moreover, this study shows that excesses in 53 Cr relative to Earth can be interpreted as representing the extent of aqueous alteration on meteorite parent bodies. Finally, the high 54 Cr anomalies measured in this meteorite make Tagish Lake one of the major targets to decipher the host of these anomalies.

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Section: Introductionsupporting

confidence: 69%

Section: Heterogeneity At a Whole Rock Scale: Tagish Lakementioning

confidence: 99%

Section: Heterogeneity At a Whole Rock Scale: Tagish Lakementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Chromium Isotopic Composition of the Ungrouped Carbonaceous Chondrite Tagish Lake

Petitat

Birck

Luu

et al. 2011

ApJ

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“…(a ) Nucleogenic heterogeneity in the solar nebula Isotopic variation at the whole-rock scale has now been identified in a number of elements in primitive meteorites (Black & Pepin 1969;Clayton et al 1973;Rotaru et al 1992;Podosek et al 1997;Dauphas et al 2002;Yin et al 2002b;Becker & Walker 2003;Brandon et al 2005;Andreasen & Sharma 2006Shukolyukov & Lugmair 2006;Carlson et al 2007;Trinquier et al 2007;Yokoyama et al 2007). For the larger of the anomalies, particularly those found in preserved Nd for a variety of meteorites expressed in parts per million difference relative to the average value of a terrestrial Nd standard (in most cases, the La Jolla Nd standard).…”

mentioning

confidence: 99%

Composition of the Earth's interior: the importance of early events

Carlson

Boyet

2008

Phil. Trans. R. Soc. A.

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The detection of excess 142 Nd caused by the decay of 103 Ma half-life 146 Sm in all terrestrial rocks compared with chondrites shows that the chondrite analogue compositional model cannot be strictly correct, at least for the accessible portion of the Earth. Both the continental crust (CC) and the mantle source of mid-ocean ridge basalts (MORB) originate from the material characterized by superchondritic 142 Nd/ 144 Nd. Thus, the mass balance of CC plus mantle depleted by crust extraction (the MORB-source mantle) does not sum back to chondritic compositions, but instead to a composition with Sm/Nd ratio sufficiently high to explain the superchondritic 142 Nd/ 144 Nd. This requires that the mass of mantle depleted by CC extraction expand to 75–100 per cent of the mantle depending on the composition assumed for average CC. If the bulk silicate Earth has chondritic relative abundances of the refractory lithophile elements, then there must exist within the Earth's interior an incompatible-element-enriched reservoir that contains roughly 40 per cent of the Earth's 40 Ar and heat-producing radioactive elements. The existence of this enriched reservoir is demonstrated by time-varying 142 Nd/ 144 Nd in Archaean crustal rocks. Calculations of the mass of the enriched reservoir along with seismically determined properties of the D″ layer at the base of the mantle allow the speculation that this enriched reservoir formed by the sinking of dense melts deep in a terrestrial magma ocean. The enriched reservoir may now be confined to the base of the mantle owing to a combination of compositionally induced high density and low viscosity, both of which allow only minimal entrainment into the overlying convecting mantle.

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