An oceanic arc origin for Archean anorthosites revealed by calcium and oxygen isotopes

Deng H, Polat A, Kusky T, Sotiriou P, Chen C, Wang S (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Earth and Planetary Science Letters Elsevier

Book Volume: 685

Article Number: 120036

DOI: 10.1016/j.epsl.2026.120036

Abstract

The mechanism of Archean crustal growth and the timing of the onset of plate tectonics have been controversial. Layered anorthosite complexes are a geologically important component of Archean terranes, however, their petrogenesis and geodynamic origin remain largely enigmatic. Here, whole-rock Ca and O isotope compositions of the most well-documented Archean (2.97-2.73 Ga) anorthosites and leucogabbros from four different Archean layered anorthosite complexes are used as petrogenetic tracers to reveal the origin of these enigmatic complexes. Results show that most Archean anorthosites and leucogabbros have modern oceanic crust-like oxygen and calcium isotope compositions that could be interpreted as the minor fractionation of olivine and clinopyroxene and the accumulation of plagioclase from Ca- and Al-rich tholeiitic parental melts. In contrast, light Ca (δ44/40Ca = 0.56‰-0.71‰) and enriched O (δ18O = 6.9‰-9.2‰) isotope compositions of Archean anorthosites could be interpreted to signify the incorporation of Archean sediments into the source region. Combined with field relationships and trace element systematics , we propose that Archean anorthosites were mostly formed in an intra-oceanic supra-subduction zone setting and plate tectonic processes involving crustal recycling have operated since at least the Mesoarchean (∼2.97 Ga).

Involved external institutions

China University of Geosciences / 中国地质大学 CN China (CN) University of Windsor (UWindsor) CA Canada (CA) Shandong University of Science and Technology (SDUST) / 山东科技大学 CN China (CN)

How to cite

APA:

Deng, H., Polat, A., Kusky, T., Sotiriou, P., Chen, C., & Wang, S. (2026). An oceanic arc origin for Archean anorthosites revealed by calcium and oxygen isotopes. Earth and Planetary Science Letters, 685. https://doi.org/10.1016/j.epsl.2026.120036

MLA:

Deng, Hao, et al. "An oceanic arc origin for Archean anorthosites revealed by calcium and oxygen isotopes." Earth and Planetary Science Letters 685 (2026).

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