The
Maniitsoq structure is a proposed 3 billion-year-old (3 Ga)
impact structure located in the
Akia terrane of the
North Atlantic Craton, centred about south-east of the town of Maniitsoq, Greenland, at . Its origin has been debated since it was first proposed as an impact structure in 2012. The proposal was criticised for not meeting established criteria for recognising
impact craters. Subsequent studies in the region have demonstrated that there is no evidence for an impact structure, and a number of observations directly contradict the earlier impact structure proposals. In support of the proposal, a study published in 2023, used electron microscopy to examine zircon grains from seven sites, including the Maniitsoq structure. The study found distinctive shock-induced planar microstructures in the zircon grains from the four recognized impact structure, as well as in the Maniitsoq structure. These microstructures were not found in grains from the two non-impact tectonic deformation structures. ==Twin towns – sister cities==