Gold nanostructures deposited on mica were excited with 400-nm sub-ps light pulses. Sub-ps transient absorption spectroscopy showed that excited hot electrons in the gold nanostructures decayed with a time constant of 13 ps through electron-phonon coupling in the nanostructures. Sub-ps time-resolved X-ray diffraction revealed that the (0010) mica lattice constant in a 1.7 mu m thick surface layer expanded with a time constant of 6 ps.