Archaean zircons in Miocene oceanic hotspot rocks establish ancient continental crust beneath Mauritius

Ashwal, Lewis D.; Wiedenbeck, Michael; Torsvik, Trond H.

doi:10.1038/ncomms14086

Cited by 70 publications

(47 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This analytical tool has previously achieved a measurement repeatability of 0.067‰ (1 s , n = 10, Ashwal et al . ) or 0.092‰ (1 s , n = 100, Nasdala et al . ) on silicates, which is reasonably typical of SIMS of this specification.…”

Section: Methodsmentioning

confidence: 99%

“…Modern microanalytical technologies can provide isotope ratio determinations at sampling masses in the low nanogram (laser ablation‐inductively coupled plasma‐mass spectrometry, LA‐ICP‐MS) to mid‐picogram ranges (secondary ion mass spectrometry, SIMS), with repeatabilities approaching or even surpassing 0.1‰ (1 s ) (e.g., Ashwal et al . , δ 18 O repeatability of 0.07‰ on n = 10 zircon measurements; Nasdala et al . , δ 18 O repeatability of 0.07‰ on n = 39 zircon measurements).…”

Section: Quantification Of Heterogeneitymentioning

confidence: 99%

See 1 more Smart Citation

Quantifying Isotopic Heterogeneity of Candidate Reference Materials at the Picogram Sampling Scale

Wiedenbeck

2017

Geostandard Geoanalytic Res

Self Cite

View full text Add to dashboard Cite

We propose a method for quantifying the in situ heterogeneity of solid materials at the picogram test portion scale, illustrating its use by investigating the oxygen isotope ratio (18O−/16O−) of four quartz samples. Using secondary ion mass spectrometry, we could estimate the intrinsic heterogeneity using a large number (~ 100) of closely spaced duplicated measurements. An analysis of variance was then applied to these large data sets to extract the measurement repeatability (typically 0.10–0.15‰, 1s) from the total variability, thereby revealing a variability ranging from 0.18‰ to 2.3‰, which can be attributed to the genuine isotope ratio heterogeneities. A small proportion of outlying values were either rejected manually after inspection, or were accommodated using robust statistics. We also evaluated two distinct approaches for estimating and correcting instrumental drift; the use of a sub‐area of the test material (if shown to have sufficiently low heterogeneity) is judged to be preferable to using a piece of unrelated silicate glass that we believe to be homogeneous. We also compared three approaches for estimating measurement repeatability, from which we show that the ‘duplicate method’ applied to the reference material is preferable to using other methods based either on the drift monitoring material or on assessing residuals of the drift monitoring material after drift correction. Finally, here we propose a strategy for predicting the number of measurements on individual fragments of a material that would be required to achieve a specified target uncertainty.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Quantification Of Heterogeneitymentioning

confidence: 99%

Quantifying Isotopic Heterogeneity of Candidate Reference Materials at the Picogram Sampling Scale

Wiedenbeck

2017

Geostandard Geoanalytic Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…[] and Ashwal et al . [] is not considered in these boundary conditions, since the age grid of Müller et al . [] (with a formal resolution of 6 arc min) differentiates only between continents and oceans and apart from the Seychelles, the entire area of the microcontinent is classified as ocean.…”

Section: Model Setupmentioning

confidence: 97%

“…[] and Ashwal et al . [], who analyzed the ages of Mauritian zircons from basaltic beach sand samples and zircons recovered from trachytic rocks, respectively, and concluded that Mauritius and the Mascarene Plateau overlie and conceal a Precambrian microcontinent underneath the hotspot track.…”

Section: Introductionmentioning

confidence: 99%

How plume‐ridge interaction shapes the crustal thickness pattern of the Réunion hotspot track

Bredow

Steinberger

Gassmöller

et al. 2017

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The Réunion mantle plume has shaped a large area of the Earth's surface over the past 65 million years: from the Deccan Traps in India along the hotspot track comprising the island chains of the Laccadives, Maldives, and Chagos Bank on the Indian plate and the Mascarene Plateau on the African plate up to the currently active volcanism at La Réunion Island. This study addresses the question how the Réunion plume, especially in interaction with the Central Indian Ridge, created the complex crustal thickness pattern of the hotspot track. For this purpose, the mantle convection code ASPECT was used to design three‐dimensional numerical models, which consider the specific location of the plume underneath moving plates and surrounded by large‐scale mantle flow. The results show the crustal thickness pattern produced by the plume, which altogether agrees well with topographic maps. Especially two features are consistently reproduced by the models: the distinctive gap in the hotspot track between the Maldives and Chagos is created by the combination of the ridge geometry and plume‐ridge interaction; and the Rodrigues Ridge, a narrow crustal structure which connects the hotspot track and the Central Indian Ridge, appears as the surface expression of a long‐distance sublithospheric flow channel. This study therefore provides further insight how small‐scale surface features are generated by the complex interplay between mantle and lithospheric processes.

show abstract

“…Our analytical method followed that of Ashwal et al (2017). Briefly, our SIMS U-Pb analyses employed a 6 nA, 16 O 2 − primary ion beam operated in Köhler mode and with a total impact energy of 23 keV, resulting in a beam diameter of approximately 25 µm on the sample's surface.…”

Section: Secondary Ion Mass Spectrometry (Sims)mentioning

confidence: 99%

Contrasting sources of Late Paleozoic rhyolite magma in the Polish Lowlands: evidence from U–Pb ages and Hf and O isotope composition in zircon

Słodczyk

Pietranik

Glynn

et al. 2018

Int J Earth Sci (Geol Rundsch)

Self Cite

View full text Add to dashboard Cite

The Polish Lowlands, located southwest of the Teisseyre-Tornquist Zone, within Trans-European Suture Zone, were affected by bimodal, but dominantly rhyolitic, magmatism during the Late Paleozoic. Thanks to the inherited zircon they contain, these rhyolitic rocks provide a direct source of information about the pre-Permian rocks underlying the Polish Lowland. This paper presents zircon U-Pb geochronology and Hf and O isotopic results from five drill core samples representing four rhyolites and one granite. Based on the ratio of inherited vs. autocrystic zircon, the rhyolites can be divided into two groups: northern rhyolites, where autocrystic zircon is more abundant and southern rhyolites, where inherited zircon dominates. We suggest that the magma sources and the processes responsible for generating high silica magmas differ between the northern and southern rhyolites. Isotopically distinct sources were available during formation of northern rhyolites, as the Hf and O isotopes in magmatic zircon differ between the two analysed localities of northern rhyolites. A mixing between magmas formed from Baltica-derived mudstone-siltstone sediments and Avalonian basement or mantle can explain the diversity between the zircon compositions from the northern localities Daszewo and Wysoka Kamieńska. Conversely, the southern rhyolites from our two localities contain zircon with similar compositions, and these units can be further correlated with results from the North East German Basin, suggesting uniform source rocks over this larger region. Based on the ages of inherited zircon and the isotopic composition of magmatic ones, we suggest that the dominant source of the southern rhyolites is Variscan foreland sediments mixed with Baltica/Avalonia-derived sediments.

show abstract

Archaean zircons in Miocene oceanic hotspot rocks establish ancient continental crust beneath Mauritius

Cited by 70 publications

References 43 publications

Quantifying Isotopic Heterogeneity of Candidate Reference Materials at the Picogram Sampling Scale

Quantifying Isotopic Heterogeneity of Candidate Reference Materials at the Picogram Sampling Scale

How plume‐ridge interaction shapes the crustal thickness pattern of the Réunion hotspot track

Contrasting sources of Late Paleozoic rhyolite magma in the Polish Lowlands: evidence from U–Pb ages and Hf and O isotope composition in zircon

Contact Info

Product

Resources

About