Permo-Triassic rift nucleation in East Antarctica revealed by low-temperature thermochronology

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Researchers collected new apatite fission-track and (U-Th)/He data across more than 5000 km of the East Antarctic margin to reconstruct its rifting history. The results show that an earlier, failed rifting episode in the Permo-Triassic period cooled and shaped the crust more strongly than the later Jurassic-Cretaceous breakup of Gondwana itself. This multi-phase rifting appears to have been driven by external tectonic events elsewhere in Gondwana, such as the rifting of Cimmerian terranes and subduction along the Proto-Pacific margin.

Abstract. The East Antarctic margin (48°-150°E) holds key information on the breakup history of Pangea and Gondwa, yet thermochronological data is scarce compared to its conjugate rifted margins in India and Australia. Here we present apatite fission track and (U-Th)/He thermochronology, revealing a pervasive record of late Carboniferous and Permo-Triassic cooling for >5000 km of the East Antarctic margin, coincident with Pangea dispersal and predating Gondwana breakup in the Cretaceous. Inverse thermal history models indicate initial rifting of Gondwana likely started in the Permo-Triassic, leading to the formation of rift basins and cooling of basin margins along the incipient margin. This rifting episode then halted and was reinitiated in the Jurassic when further extension ultimately led to continental breakup, with the latter event resulting in less than 1 km of erosion in East Antarctica. Our results demonstrate that the failed Permo-Triassic rift phase had a greater effect on the present margin’s upper crustal thermal evolution than subsequent successful lithospheric rupture in the Jurassic and Cretaceous. While detailed interpretations are limited due to Antarctica’s extensive ice-cover, we suggest that external geodynamic forces such as the rifting of the Cimmerian terrane and the opening of the Meso-Tethys or subduction roll-back along the Proto-Pacific margin of Gondwana may have shifted the extensional locus away from the Antarctic margin and are likely drivers for this multi-phase rifting development.

Palaeoreconstruction map of East Gondwana at 265 Ma showing the East Antarctic margin, study area and sample locations.
Fig. 1. Left: Palaeoreconstruction for east Gondwana at 265 Ma, highlighting the East Antarctic conjugate margin (Müller et al., 2019). Curved box indicates study area (between c. [modern] 48 and 150◦ E) and inset for Fig. 2. Red diamonds show sample locations. Grey circles indicate AFT and AHe sample locations from the literature (see Supplementary File 1). Major Permian basins shown in light brown, after Isbell and Cuneo (1996), Aitken et al. (2023, Antarctica), Mukhopadhyay et al. (2010, India), and Kohn et al. (2002, Australia). Subglacial basins are marked with a dashed outline. Question marks (?) indicate suspected Permian deposition (Aitken et al., 2023; Baranov and Morelli, 2023). PCM = Prince Charles Mountains, PEL = Princess Elizabeth Land, KR = Knox Rift, SC = Sabrina Coast, TA = Terre Adelie, AB = Aurora Basin, SB = Sabrina Basin, VB = Vincennes Basin, WSB = Wilkes Subglacial Basin, PGB = Pranhita-Godvari Basin, MG = Mahanadi Graben. The asterisk (*) indicates the modern South Pole. Right: Time-space plot showing in colour major relevant events that affected the conjugate margin. Pattern infill shows glacial/sedimentation events within major basins as well as the Gondwana-forming Kuunga Orogeny (e.g. Daczko et al., 2018). 2 From Mayer-Ullmann et al. (2026), Earth and Planetary Science Letters, reproduced under CC BY 4.0.
Mayer-Ullmann, F., Glorie, S., Hand, M., Boone, S.C., Nixon, A., Danišík, M., Halpin, J.A. and Mulder, J.A., 2026. Permo-Triassic rift nucleation in East Antarctica revealed by low-temperature thermochronology. Earth and Planetary Science Letters, 681, p.119950. https://doi.org/10.1016/j.epsl.2026.119950

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