An archaeological dig was an effort to excavate a historical site for study.
Rumors of Iconian artifacts being uncovered at various archaeological dig sites, including one at Denius III, lead Donald Varley to locate their homeworld, Iconia, in the Romulan Neutral Zone. (TNG: "Contagion")
When discussing Vhnori burial rituals with B'Elanna Torres, Chakotay opined that they must believe in an afterlife, given the elaborate nature of said rituals. Torres disagreed, giving the example of Klingons, who disposed corpses efficiently without such rituals and still believed in an afterlife. Chakotay was about to counter her with evidence from digs on the Klingon homeworld, but was interrupted before he could continue. (VOY: "Emanations")