This project investigates the effects of diagenesis on δ7Li in shallow-marine carbonates collected from the Viki Drill Core during the Late Ordovician, Hirnantian Glaciation. The research examines 14 samples measured for δ7Li value, Metal/Ca ratios, and two mineralogical calcium carbonate endmembers, "pristine" aragonite and "altered" dolomite. The results suggest that while marine diagenesis raises the δ7Li values to more positive seawater values, the light δ7Li values indicate potential meteoric diagenesis and/or lighter seawater δ7Li values during the glaciation. This work focuses on the limitations of interpreting geochemical proxies in calcium carbonate archives due to diagenetic alteration.