Oxygen isotopic composition of relict olivine grains in cosmic spherules: Links to chondrules from carbonaceous chondrites

Rudraswami, N. G.; Prasad, M.M.; Nagashima, K.; Jones, R. H.

doi:10.1016/j.gca.2015.05.004

Cited by 24 publications

(67 citation statements)

References 93 publications

(266 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The olivines in UOCs also have low CaO content, hence an insignificant number of micrometeorites can be related to ordinary chondrites (Beckerling & Bishcoff 1995). The above conclusion is also supported by oxygen isotopic studies on relict olivine in micrometeorites that fall in the range of thechondrule from carbonaceous chondrites rather than ordinary chondrites (e.g., Rudraswami et al 2015bRudraswami et al , 2016. The rectangle is the region where thelikelihood of finding the particle within it is maximum.…”

Section: Relict Olivine In Micrometeoritesmentioning

confidence: 57%

“…The bulk Ca/Si (atomic) and Al/Si (atomic) ratios are close to the solar composition irrespective of the type of cosmic spherule (Rudraswami et al 2015b). However, Mg-rich olivine is different from the bulk chemical composition of the particle.…”

Section: Temperature Size and Entry Anglementioning

confidence: 73%

“…100 μm) can undergo extensive melting and vaporization depending on the ZA and entry velocity. Here we have restricted the entry velocity 16 km s −1 , beyond which the particles (sizes ranging from 100 to 700 μm) lose substantial mass and undergo significant compositional change (Rudraswami et al 2015b).…”

Section: Temperature Size and Entry Anglementioning

confidence: 99%

“…Such grains potentially record the original composition when they formed in solar nebula. Two different entry velocities of 11 and 16 km s −1 are considered in the present study, as with faster particles complete ablation occurs (Vondrak et al 2008;Rudraswami et al 2015b).…”

Section: Temperature Size and Entry Anglementioning

confidence: 99%

See 3 more Smart Citations

Relict Olivines in Micrometeorites: Precursors and Interactions in the Earth’s Atmosphere

Rudraswami

Prasad

Dey

et al. 2016

ApJ

Self Cite

View full text Add to dashboard Cite

Antarctica micrometeorites (∼1200) and cosmic spherules (∼5000) from deep sea sediments are studied using electron microscopy to identify Mg-rich olivine grains in order to determine the nature of the particle precursors. Mg-rich olivine (FeO<5wt%) in micrometeorites suffers insignificant chemical modification during its history and is a well-preserved phase. We examine 420forsterite grains enclosed in 162 micrometeorites of different types -unmelted, scoriaceous, and porphyritic-in this study. Forsterites in micrometeorites of different types are crystallized during their formation in solar nebula; their closest analogues are chondrule components of CV-type chondrites or volatile rich CM chondrites. The forsteritic olivines are suggested to have originated from a cluster of closely related carbonaceous asteroids that have Mg-rich olivines in the narrow range of CaO (0.1-0.3wt%), Al 2 O 3 (0.0-0.3wt%), MnO (0.0-0.3wt%), and Cr 2 O 3 (0.1-0.7wt%). Numerical simulations carried out with the Chemical Ablation Model (CABMOD) enable us to define the physical conditions of atmospheric entry that preserve the original compositions of the Mg-rich olivines in these particles. The chemical compositions of relict olivines affirm the role of heating at peak temperatures and the cooling rates of the micrometeorites. This modeling approach provides a foundation for understanding the ablation of the particles and the circumstances in which the relict grains tend to survive.

show abstract

Section: Relict Olivine In Micrometeoritesmentioning

confidence: 57%

Section: Temperature Size and Entry Anglementioning

confidence: 73%

Section: Temperature Size and Entry Anglementioning

confidence: 99%

Section: Temperature Size and Entry Anglementioning

confidence: 99%

See 2 more Smart Citations

Relict Olivines in Micrometeorites: Precursors and Interactions in the Earth’s Atmosphere

Rudraswami

Prasad

Dey

et al. 2016

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…Micrometeorites are the largest contributors of extra-terrestrial material; this material is recovered from the Earthʼs surface using different collection techniques that target the stratosphere, Antarctica, and deep-sea sediments (Love & Brownlee 1993;Taylor et al 1998;Peucker-Ehrenbrink & Ravizza 2000;Plane 2012;Prasad et al 2013). The micrometeorites found on the Earthʼs surface have distinct chemical compositions that show similarities and differences with respect to the precursors they originate from; however, in general, a large number of micrometeorites are related to carbonaceous chondrites (e.g., Kurat et al 1994;Brownlee et al 1997;Taylor et al 2000Taylor et al , 2012Yada et al 2005;Rudraswami et al 2011Rudraswami et al , 2012Rudraswami et al , 2014Rudraswami et al , 2015aRudraswami et al , 2015bRudraswami et al , 2016a. The deviations in the chemical compositions from the precursors are caused by modification that occurs during melting and vaporization that take place as these particles enter into the Earthʼs atmosphere.…”

Section: Introductionmentioning

confidence: 99%

Ablation and Chemical Alteration of Cosmic Dust Particles During Entry Into the Earth’s Atmosphere

Rudraswami

Prasad

Dey

et al. 2016

ApJS

Self Cite

View full text Add to dashboard Cite

Most dust-sized cosmic particles undergo ablation and chemical alteration during atmospheric entry, which alters their original properties. A comprehensive understanding of this process is essential in order to decipher their preentry characteristics. The purpose of the study is to illustrate the process of vaporization of different elements for various entry parameters. The numerical results for particles of various sizes and various zenith angles are treated in order to understand the changes in chemical composition that the particles undergo as they enter the atmosphere. Particles with large sizes (> few hundred μm) and high entry velocities (>16 km s −1 ) experience less time at peak temperatures compared to those that have lower velocities. Model calculations suggest that particles can survive with an entry velocity of 11 km s −1 and zenith angles (ZA) of 30°-90°, which accounts for ∼66% of the region where particles retain their identities. Our results suggest that the changes in chemical composition of MgO, SiO 2 , and FeO are not significant for an entry velocity of 11 km s −1 and sizes <300 μm, but the changes in these compositions become significant beyond this size, where FeO is lost to a major extent. However, at 16 km s −1 the changes in MgO, SiO 2 , and FeO are very intense, which is also reflected in Mg/Si, Fe/Si, Ca/Si, and Al/Si ratios, even for particles with a size of 100 μm. Beyond 400 μm particle sizes at 16 km s −1 , most of the major elements are vaporized, leaving the refractory elements, Al and Ca, suspended in the troposphere.

show abstract

Triple‐oxygen isotopes of stony micrometeorites by secondary ion mass spectrometry (SIMS): Olivine, basaltic glass and iron oxide matrix effects for sensitive high‐mass resolution ion microprobe‐stable isotope (SHRIMP‐SI)

McKibbin,

Ávila,

Ireland

et al. 2024

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

RationaleMicrometeorites are extraterrestrial particles smaller than ~2 mm in diameter, most of which melted during atmospheric entry and crystallised or quenched to form ‘cosmic spherules’. Their parentage among meteorite groups can be inferred from triple‐oxygen isotope compositions, for example, by secondary ion mass spectrometry (SIMS). This method uses sample efficiently, preserving spherules for other investigations. While SIMS precisions are improving steadily, application requires assumptions about instrumental mass fractionation, which is controlled by sample chemistry and mineralogy (matrix effects).MethodsWe have developed a generic SIMS method using sensitive high‐mass resolution ion micro probe‐stable isotope (SHRIMP‐SI) that can be applied to finely crystalline igneous textures as in cosmic spherules. We correct for oxygen isotope matrix effects using the bulk chemistry of samples obtained by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) and model bulk chemical compositions as three‐component mixtures of olivine, basaltic glass and Fe‐oxide (magnetite), finding a unique matrix correction for each target.ResultsOur first results for cosmic spherules from East Antarctica compare favourably with established micrometeorite groups defined by precise and accurate but consumptive bulk oxygen isotope methods. The Fe‐oxide content of each spherule is the main control on magnitude of oxygen isotope ratio bias, with effects on δ18O up to ~6‰. Our main peak in compositions closely coincides with so‐called ‘Group 1’ objects identified by consumptive methods.ConclusionsThe magnitude of SIMS matrix effects we find is similar to the previous intraspherule variations, which are now the limiting factor in understanding their compositions. The matrix effect for each spherule should be assessed quantitatively and individually, especially addressing Fe‐oxide content. We expect micrometeorite triple‐oxygen isotope compositions obtained by SIMS to converge on the main clusters (Groups 1 to 4) after correction firstly for magnetite content and secondarily for other phases (e.g., basaltic glass) in each target.

show abstract

Oxygen isotopic composition of relict olivine grains in cosmic spherules: Links to chondrules from carbonaceous chondrites

Cited by 24 publications

References 93 publications

Relict Olivines in Micrometeorites: Precursors and Interactions in the Earth’s Atmosphere

Relict Olivines in Micrometeorites: Precursors and Interactions in the Earth’s Atmosphere

Ablation and Chemical Alteration of Cosmic Dust Particles During Entry Into the Earth’s Atmosphere

Triple‐oxygen isotopes of stony micrometeorites by secondary ion mass spectrometry (SIMS): Olivine, basaltic glass and iron oxide matrix effects for sensitive high‐mass resolution ion microprobe‐stable isotope (SHRIMP‐SI)

Contact Info

Product

Resources

About