V. C. Bennett

The two Isua supracrustal belt area (Greenland) papers by Zuo et al. (2021, https://doi.org/10.1029/2020tc006514 ) and Ramírez‐Salazar et al. (2021, https://doi.org/10.1029/2020TC006516 ) contain no evidence supporting an Eoarchean “heat‐pipe” geodynamic regime and yet no evidence negating a mobile lid one. From quartz micro‐fabric studies, Zuo et al. (2021, https://doi.org/10.1029/2020tc006514 ) argued for Eoarchean “relatively equal strain distributed across the belt.” This contradicts clear meso‐ and macro‐scale evidence for strongly heterogeneous Eoarchean deformation before the later deformed and metamorphosed ∼3,500 to 2,750 Ma Ameralik dykes were intruded. The Zuo et al. strain indicators relate to syn‐amphibolite facies Neoarchean basin and dome formation throughout the ∼250 km extent of the Eoarchean gneiss complex. Ramírez‐Salazar et al. (2021, https://doi.org/10.1029/2020TC006516 ) argued the Isua area's metamorphic signature reflects a uniform Eoarchan “heat‐pipe” geodynamic regime. However, observed Eoarchean tectonothermal conditions are more diverse, including ultra‐high‐pressure relicts in peridotite lenses with supra‐subduction zone attributes, and are incompatible with a “heat‐pipe” regime.