The apex of the Guérande leucogranite is structurally located below a U deposit.
Leaching of U likely occurred at the apical zone of the intrusion.
Sub-solidus alteration with meteoric fluids affected the deformed facies at the apex.
Hydrothermal circulation in the granite is sub-synchronous with U mineralization.
The Guérande leucogranite is proposed as the main source for the U of the deposit.