The socle stones of the Great Temple in the Lower City of the Hittite capital city, Hattusha (Çorum Province) have been studied
for the first time by petrographic and geochemical analysis (Sr isotope, stable isotope, and trace element geochemistry). Study objectives
were to determine the carbonate facies of the stone samples used in the Great Temple and investigate their possible sources. Petrographic
analysis of 10 limestone samples presents five clusters of different microfacies. Stable isotope (δ13C and δ18O) analysis displayed the
presence of 5 groups in parallel with petrographic analysis. Trace element analysis of the same groups displayed considerable difference
among the stone samples and 87Sr/86Sr isotope ratios change between 0.70697 and 0.706867. Based on the results, it can be stated that the
building using stones are from probably five different sources. This is of great importance to better understand the construction process
and the acquisition of the building materials.