The shocking state of apatite and merrillite in shergottite Northwest Africa 5298 and extreme nanoscale chlorine isotope variability revealed by atom probe tomography

•Chlorapatites and merrillites in NWA 5298 have a wide-range of shock nanostructures.•Shock features in apatite are linked to elemental and chlorine isotope heterogeneity.•Atom probe tomography can yield accurate chlorine isotope data at ‰ precision.•Nanoscale boundaries contain isotopically light chlorine mobilized during shock.•The primary chlorine isotopic composition of NWA 5298 is −0.3 ± 0.6 ‰ (2σ)