MgO and LiNbO 3 single crystals were bombarded with GeV swift heavy ions (Pb, Gd) and 30MeV C60 clusters to study the damage production induced by giant electronic processes at stopping power up to 100keV/nm. The defect creation was characterized by optical absorption, transmission electron microscopy (TEM) and Rutherford backscattering spectrometry in channeling geometry (RBS-C). In MgO point defects (F type centers) and extended defects (dislocation loops) were created by ionization processes in addition to those associated with nuclear collisions. The F-center concentration induced by electronic energy excitations was studied at different temperatures and as a function of the particle electronic energy losses. TEM revealed that dislocation loops were produced close to the particle trajectories and amorphization was never observed. On the opposite, in LiNbO3 continuous amorphous tracks were evidenced above a threshold near 5keV/nm. The dependance of this effects with various solid state parameters will be discussed.