The Hyperion-II radio-frequency oxygen ion source on the UCLA ims1290 ion microprobe: Beam characterization and applications in geochemistry and cosmochemistry

Liu, Ming‐Chang; McKeegan, Kevin D.; Harrison, T. Mark; Jarzebinski, G.; Vltava, Lvcian

doi:10.1016/j.ijms.2017.11.007

Cited by 41 publications

(23 citation statements)

References 12 publications

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“…S7 30 Si/ 28 Si (1 SD), which are commensurate with the internal measurement errors, and better than reconnaissance O-isotope results obtained for the Hyperion-II oxygen plasma source (ref. 58 and SI Appendix, Fig. S7).…”

Section: Methodsmentioning

confidence: 99%

Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon

Trail

Boehnke

Savage

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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Hydrosphere interactions and alteration of the terrestrial crust likely played a critical role in shaping Earth’s surface, and in promoting prebiotic reactions leading to life, before 4.03 Ga (the Hadean Eon). The identity of aqueously altered material strongly depends on lithospheric cycling of abundant and water-soluble elements such as Si and O. However, direct constraints that define the character of Hadean sedimentary material are absent because samples from this earliest eon are limited to detrital zircons (ZrSiO4). Here we show that concurrent measurements of Si and O isotope ratios in Phanerozoic and detrital pre-3.0 Ga zircon constrain the composition of aqueously altered precursors incorporated into their source melts. Phanerozoic zircon from (S)edimentary-type rocks contain heterogeneous δ18O and δ30Si values consistent with assimilation of metapelitic material, distinct from the isotopic character of zircon from (I)gneous- and (A)norogenic-type rocks. The δ18O values of detrital Archean zircons are heterogeneous, although yield Si isotope compositions like mantle-derived zircon. Hadean crystals yield elevated δ18O values (vs. mantle zircon) and δ30Si values span almost the entire range observed for Phanerozoic samples. Coupled Si and O isotope data represent a constraint on Hadean weathering and sedimentary input into felsic melts including remelting of amphibolites possibly of basaltic origin, and fractional addition of chemical sediments, such as cherts and/or banded iron formations (BIFs) into source melts. That such sedimentary deposits were extensive enough to change the chemical signature of intracrustal melts suggests they may have been a suitable niche for (pre)biotic chemistry as early as 4.1 Ga.

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Section: Methodsmentioning

confidence: 99%

Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon

Trail

Boehnke

Savage

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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“…At this mass resolution 24 MgH + is not totally resolved from 25 Mg. With the vacuum between 10 -9 and 10 -10 Torr the contribution of 24 MgH + on 25 Mg is negligible (Luu et al, 2013;Liu et al, 2018).…”

Section: Secondary Ion Mass Spectrometry (Sims)mentioning

confidence: 99%

Time and duration of chondrule formation: Constraints from 26Al-26Mg ages of individual chondrules

Pape

Mezger

Bouvier

et al. 2019

Geochimica et Cosmochimica Acta

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Chondrules from unequilibrated ordinary and carbonaceous chondrites belong to the oldest and most primitive materials from the early solar system and record chemical and isotopic signatures relating to their formation and evolution. These signatures allow tracing protoplanetary disk processes that eventually led to the formation of planetary building blocks and rocky planets. 26 Al-26 Mg ages based on mineral-mesostasis isochrons of 31 porphyritic ferromagnesian chondrules, that belong mainly to type-II, constrain the time of chondrule melting prior to incorporation into the respective chondrite parent bodies. For this study chondrules from the unequilibrated L, L(LL) and LL ordinary chondrites (UOCs) NWA 5206, NWA 8276, MET 96503, MET 00452, MET 00526, NWA 7936 and QUE 97008 were selected, which are of petrologic types 3.00 to 3.15 and were thus least metamorphosed after formation. Magnesium and Al isotopes were measured in-situ by Secondary Ion Mass Spectrometry (SIMS) using a CAMECA 1280 ims. 26 Mg excess from in-situ decay of 26 Al correlating with 27 Al/ 24 Mg has been detected in the mesostasis of all but one chondrule. The initial Al isotopic compositions (26 Al/ 27 Al)0 and 26 Mg/ 24 Mg ratios (d 26 Mg*0) deduced from internal mineral isochron regressions range from (9.5 ± 2.8) × 10-6 to (3.1 ± 1.2) × 10-6 and-0.020 ± 0.028‰ to 0.011 ± 0.039‰, respectively. The corresponding chondrule ages (∆tCAI), calculated relative to calcium-aluminum-rich inclusions (CAIs) using the canonical 26 Al/ 27 Al = (5.23 ± 0.13) × 10-5 , are between 1.76 %&.'()&.*+ and 2.92 %&.*.)&./0 Ma and date melt formation and thus the primary chondrule formation from dust-like precursors or reprocessing of older chondrules. The age range agrees with those acquired with different short-lived chronometers and with published 26 Al-26 Mg ages, the majority of which were obtained for chondrules from the Bishunpur and Semarkona meteorites, although no chondrule with (26 Al/ 27 Al)0 > 10-5 was found. Chondrules in single chondrite samples or between different chondrite groups show no distinct age distributions. The initial 26 Al/ 27 Al of the oldest chondrules in the L(LL)/LL and L chondrite samples are identical within their 1σ uncertainties and yield a mean age of 1.99 %&.&1)&.&1 Ma and 1.81 %&.0&)&.00 Ma, respectively. The oldest chondrules from six of the seven studied samples record a mean age of 1.94 %&.&+)&.&(Ma. Since heating events in the protoplanetary disk could have partially reset the Al-Mg systematics in pre-existing chondrules and this would have shifted recorded 26 Al-26 Mg ages toward younger dates, the oldest mean age of 1.81 %&.0&)&.00 Ma recorded in L chondrite chondrules is interpreted to date the rapid and punctuated onset of chondrule formation. The density distribution of chondrule ages from this study, which '. 12 %&.**

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“…The NanoSIMS platform, including important differences relative to other SIMS instruments, is described in [12]. An important note is that the instrument used in this study is equipped with the new Hyperion-II radio frequency plasma oxygen ion source (described in [24,25]), which was used to generate the O − beam used in this study. For isotopic measurements, the NanoSIMS primary column was tuned to achieve a ~200 pA beam of O − with a diameter of ~1 µm at the sample surface ( Figure 1).…”

Section: Nanosims Analysis and Data Processingmentioning

confidence: 99%

A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the 235U/238U Ratio Determination by Using the Molecular 235U16O and 238U16O Secondary Ions

et al. 2019

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A NanoSIMS 50 L was used to study the relationship between the 235U/238U atomic and 235U16O/238U16O molecular uranium isotope ratios determined from a variety of uranium compounds (UO2, UO2F2, UO3, UO2(NO3)2·6(H2O), and UF4) and silicates (NIST-610 glass and the Plesovice zircon reference materials, both containing µg/g uranium). Because there is typically a greater abundance of 235U16O+ and 238U16O+ molecular secondary ions than 235U+ and 238U+ atomic ions when uranium-bearing materials are sputtered with an oxygen primary ion beam, the goal was to understand whether use of 235U16O/238U16O has the potential for improved accuracy and precision when compared to the 235U/238U ratio. The UO2 and silicate reference materials showed the greatest potential for improved accuracy and precision through use of the 235U16O/238U16O ratio as compared to the 235U/238U ratio. For the UO2, which was investigated at a variety of primary beam currents, and the silicate reference materials, which were only investigated using a single primary beam current, this improvement was especially pronounced at low 235U+ count rates. In contrast, comparison of the 235U16O/238U16O ratio versus the 235U/238U ratio from the other uranium compounds clearly indicates that the 235U16O/238U16O ratio results in worse precision and accuracy. This behavior is based on the observation that the atomic (235U+ and 238U+) to molecular (235U16O+ and 238U16O+) secondary ion production rates remain internally consistent within the UO2 and silicate reference materials, whereas it is highly variable in the other uranium compounds. Efforts to understand the origin of this behavior suggest that irregular sample surface topography, and/or molecular interferences arising from the manner in which the UO2F2, UO3, UO2(NO3)2·6(H2O), and UF4 were prepared, may be a major contributing factor to the inconsistent relationship between the observed atomic and molecular secondary ion yields. Overall, the results suggest that for certain bulk compositions, use of the 235U16O/238U16O may be a viable approach to improving the precision and accuracy in situations where a relatively low 235U+ count rate is expected.

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The Hyperion-II radio-frequency oxygen ion source on the UCLA ims1290 ion microprobe: Beam characterization and applications in geochemistry and cosmochemistry

Cited by 41 publications

References 12 publications

Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon

Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon

Time and duration of chondrule formation: Constraints from 26Al-26Mg ages of individual chondrules

A NanoSIMS 50 L Investigation into Improving the Precision and Accuracy of the 235U/238U Ratio Determination by Using the Molecular 235U16O and 238U16O Secondary Ions

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