Oxygen isotopes trace the origins of Earth’s earliest continental crust

Smithies, R. Hugh; Lu, Yongjun; Kirkland, Christopher L.; Johnson, Tim; Mole, David R.; Champion, David C.; Martin, Laure; Jeon, Heejin; Wingate, Michael T.D.; Johnson, Simon P.

doi:10.1038/s41586-021-03337-1

Cited by 92 publications

(37 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, a similar mild elevation of zircon δ 18 O was reported in Archean granitoids from the Pilbara Craton and the transition was defined at ca. 2.9 Ga [ 9 ]. However, their classifications of the rock types are ambiguous, and they ignored the previously reported δ 18 O elevations at ca.…”

Section: Discussionmentioning

confidence: 99%

“…The supracrustal materials could be cherts and/or shales deposited in the Paleoarchean or earlier, which have relatively high δ 18 O values of 10‰–22‰ [ 22 , 23 ] and 6‰–11‰ [ 22 ], respectively. Alternatively, the mafic oceanic crust that had experienced low-temperature seawater hydrothermal alteration during basalt eruption along mid-ocean ridges may also acquire elevated δ 18 O values [ 6 , 9 , 23 ], and the incorporation of these high δ 18 O materials into the sources of the younger TTGs (≤3230 Ma) is possibly responsible for their elevated δ 18 O values. If we could take the average of 3.0 Ga shales with δ 18 O of 10‰ [ 22 ] as the endmember of supracrustal sediments, a simple mass balance calculation would yield ∼23% supracrustal sediments in the sources of the ≤3230 Ma TTGs when adopting the average zircon δ 18 O of 6.4‰ for the BGGT TTGs.…”

Section: Discussionmentioning

confidence: 99%

“…Recycling of such altered materials into magma sources results in heavy O isotope signatures for magmatic minerals. However, the timing and mechanism for the recycling are highly debated [ 9 ], casting doubt on the styles of plate tectonics on early Earth.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

Wang

Tang

Moyen

et al. 2021

National Science Review

View full text Add to dashboard Cite

Recycling of supracrustal materials, and in particular hydrated rocks, has profound impacts on mantle composition and thus on the formation of continental crust because water modifies the physical properties of lithological systems and the mechanisms of partial melting and fractional fractionation. On the modern Earth, plate tectonics offers an efficient mechanism for mass transport from the Earth's surface to its interior, but how far this mechanism dates back in the Earth's history is still uncertain. Here, we use zircon O isotopes to track recycling of supracrustal materials into the magma sources of early Archean igneous suites from the Kaapvaal craton, southern Africa. The mean δ18O values of zircon from TTG (tonalite–trondhjemite–granodiorite) rocks abruptly increase at the Paleo-Mesoarchean boundary (ca. 3230 million years ago; Ma), from mantle zircon values of 5–6‰ to approaching 7.1‰, and this increase occurs in the ≤ 3230 Ma rocks with elevated Dy/Yb ratios. The 18O enrichment is a unique signature of low temperature water-rock interaction on the Earth's surface. Because the later phase was emplaced into the same crustal level as the older one and TTG magmas would derive from melting processes in the garnet stability field (>40 km depth), we suggest that this evident shift in TTG zircon O isotopic compositions records the onset of recycling of the mafic oceanic crust that underwent the seawater hydrothermal alteration at low temperature. The onset of enhanced recycling of the supracrustal materials may also develop elsewhere in other Archean cratons and reflects a significant change in tectonic realm during craton formation and stabilization, which may be important processes for the operation of plate tectonics on early Earth.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

Wang

Tang

Moyen

et al. 2021

National Science Review

View full text Add to dashboard Cite

show abstract

“…Mantle. An alternative explanation for the enriched trace elemental composition in the Nsuze, Mozaan, Hlagothi, Usushwana, and Kubuta lavas could be a lithospheric mantle source beneath the Eastern Kaapvaal Craton that had previously been overprinted metasomatically, similar to what has been proposed for the lithospheric mantle beneath the Pilbara Craton (e.g., [85]). As a consequence, partial melting of metasomatized lithospheric mantle or plume-interaction with such a metasomatized mantle would produce similar geochemical characteristics to crustal contamination, i.e., high Th/Nb and elevated LREE (e.g., [85,86]), as observed in the aforementioned volcanic sequences.…”

Section: Melting Of Metasomatized Lithosphericmentioning

confidence: 69%

“…The addition of fluids that caused metasomatism of the lithospheric mantle prior to magma formation could have occurred in two ways, either by ancient subduction processes during crust formation (e.g., [22,29,87]) or by a process analogous to sagduction such as proposed for the Pilbara Craton (e.g., [85,86,88,89]). These two possibilities are controversially discussed and determining which of the two possibilities is more plausible for a possible metasomatic overprint of the lithospheric mantle beneath the Kaapvaal Craton is beyond the scope of this paper.…”

Section: Melting Of Metasomatized Lithosphericmentioning

confidence: 99%

A Mesoarchean Large Igneous Province on the Eastern Kaapvaal Craton (Southern Africa) Confirmed by Metavolcanic Rocks from Kubuta, Eswatini

et al. 2022

View full text Add to dashboard Cite

Mesoarchean magmatism is widespread on the eastern margin of the Kaapvaal Craton, but its origin is still poorly understood, mainly because geochemical data is rare. To shed some light on the source of this Mesoarchean magmatism and to relate different Mesoarchean volcanic sequences to each other, we provide major and trace element data as well as Hf-Nd isotope compositions of amphibolites sampled close to the Kubuta Ranch in south-central Eswatini. These amphibolites, so far, were of unknown correlation to any volcanic sequence in Eswatini or South Africa. Hence, the aim of our study is to characterize the mantle source composition of these volcanic rocks and, furthermore, to constrain their genetic relation to other volcanic sequences in Eswatini and South Africa. Our findings reveal that, based on coherent trace element patterns and similar Nd isotope characteristics, the Kubuta volcanic rocks can be genetically linked to the ca. 3.0 Ga Usushwana Igneous Complex in West-Central Eswatini and the ca. 2.9 Ga Hlagothi Complex located in the KwaZulu-Natal province. In contrast, the coeval ca. 3.0 Ga Nsuze and ca. 2.9 Ga Mozaan Groups (Pongola Supergroup) of south-central Eswatini and northern KwaZulu-Natal province have slightly enriched compositions compared to the newly sampled Kubuta volcanic rocks. Our results suggest that the Nsuze and Mozaan Groups were sourced from a primitive mantle reservoir, whereas the Usushwana, Hlagothi, and Kubuta mafic rocks were derived by melting of a more depleted mantle source comparable to that of modern depleted MORB. Furthermore, our assimilation-fractional crystallization (AFC) calculations and Nd isotope constraints reveal that some samples were contaminated by the crust and that the crustal contaminants possibly represent felsic rocks related to the ca. 3.5 Ga crust-forming event in the Ancient Gneiss Complex. Alternatively, melting of a metasomatized mantle or plume-lithospheric mantle interaction may also produce the trace element and isotopic compositions observed in the samples. From a synthesis of our geochemical observations and age data from the literature, we propose a refined petrogenetic model, for a continental flood basalt setting in a Mesoarchean large igneous province on the eastern Kaapvaal Craton. Our petrogenetic model envisages two magma pulses sourced from a primitive mantle reservoir that led to the formation of the Nsuze (first) and Mozaan (second) lavas. Conductive heating of ambient depleted mantle by the mantle plumes caused partial melting that led to the formation of the Usushwana Igneous Complex associated with the first magmatic event (Nsuze) and the Hlagothi Igneous Complex associated with the second magmatic event (Mozaan). However, due to lacking age data of sufficient resolution, it is not possible to affiliate the Kubuta lavas to either the first or the second magmatic event.

show abstract

Visualizing the Nanoscale Oxygen and Cation Transport Mechanisms during the Early Stages of Oxidation of Fe–Cr–Ni Alloy Using In Situ Atom Probe Tomography

Devaraj

Barton

et al. 2022

Adv Materials Inter

View full text Add to dashboard Cite

In forensics, 18 O mapping in materials can be instrumental for tracing geographical origins of animals and humans. [17] Among the different methods used to study the oxidation mechanisms in solid materials, in situ environmental transmission electron microscopy (TEM) and in situ scanning tunneling microscopy are powerful for studying the atomic-scale structural changes associated with the early stages of oxidation. [1,3,5,18,19] However, these in situ techniques lack the sensitivity to distinguish individual oxygen isotopes. At the same time, nanosecondary ion mass spectrometry (SIMS) and other massspectrometry-based techniques, which are highly sensitive for oxygen isotopes, lack 3D sub-nanometer-scale spatial resolutions. [14,17,20,21] Recently, ex situ atom probe tomography (APT) studies validated the ability of APT to achieve sub-nanometerscale spatially resolved mapping of 18 O isotope distribution in materials. [10,[22][23][24][25] However, expanding this ability of APT in mapping 18 O quantitatively at sub-nanometer scale spatial resolution toward in situ oxidation studies is yet to be demonstrated.Here, we demonstrate for the first time in situ APT analysis of oxygen diffusion in a model Fe-18 wt% Cr-14 wt% Ni model alloy (from here on called as Fe18Cr14Ni) using an 18 O isotopic Understanding the early stages of interactions between oxygen and material surfaces-especially at very high spatial resolutions-is highly beneficial for fields ranging from materials degradation, corrosion, geological sciences, forensics, and catalysis. The ability of in situ atom probe tomography (APT) is demonstrated to track the diffusion of oxygen and metal ions at nanoscale spatial resolution during the early stages of oxidation of a model Fe-Cr-Ni alloy. Using 18 O isotope tracers in these in situ APT experiments and complementary ex situ multimodal microscopy, spectroscopy, and computational simulations allows to precisely analyze the kinetics of oxidation and determine that outward cation diffusion to oxide/air interface is the primary mechanism for intragranular oxide growth in this alloy at 300 °C. This unique in situ isotopic tracer APT approach and the insights gained can be highly beneficial for studying early stages of gas-surface reactions in a broad array of materials.

show abstract

Oxygen isotopes trace the origins of Earth’s earliest continental crust

Cited by 92 publications

References 54 publications

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

The onset of deep recycling of supracrustal materials at the Paleo-Mesoarchean boundary

A Mesoarchean Large Igneous Province on the Eastern Kaapvaal Craton (Southern Africa) Confirmed by Metavolcanic Rocks from Kubuta, Eswatini

Visualizing the Nanoscale Oxygen and Cation Transport Mechanisms during the Early Stages of Oxidation of Fe–Cr–Ni Alloy Using In Situ Atom Probe Tomography

Contact Info

Product

Resources

About