  The recent measurement of the spectra of heavy nuclei carried out with the
AMS-02 experiment provided us with the most complete set of data on cosmic ray
fluxes to date, and allowed us to test the standard model for the transport of
these particles through the Galaxy to the finest details. We show that the
parameters derived from lighter primary and secondary elements in the cosmic
radiation also lead to a good description of the data on heavier nuclei, with
no need to invoke different injection spectra for such nuclei, provided the
whole chain of fragmentation is properly accounted for. The only exception to
this finding is represented by iron nuclei, which show a very unusual trend at
rigidity $\lesssim 100$ GV. This trend reflects in a Fe/O ratio that is at odds
with the results of the standard model of cosmic ray transport, and is in
contradiction with data collected by HEAO, ACE-CRIS and Voyager at lower
energy. We speculate on possible origins of such findings.
