Determination of the part of γ families produced from nucleus-nucleus interactions at 1015-1016eV energies at mountain level

Possibility of determining part of γ-families produced from nucleus-nucleus interactions at 1015-1016 eV energies at mountain level is discussed. Three types of criteria of γ-families classification produced from proton-nucleus and nucleus-nucleus interactions are developed. Criteria are based on analysis of characteristics of artificial γ-families estimated by MSF-model. Experimental value of the part of detected nucleus-nucleus families happened to be equal η=0.14-0.22, that is approximately one-half the corresponding value obtained from the MSF-model with the dominating iron nuclei contribution. Experimental data agree with the supposition on normal chemical composition of primary cosmic radiation at the energy of E0=1015-1016 eV