If one is working on an archaeological dig and finds an artifact related to idolatry, especially an idol itself, is one obligated to then destroy it or can they pass it on to a non-Jew present?

There is an almost definite halachic probability ("chazaka"), that over time, the idol was annulled by the gentile idolaters themselves, for they saw that their god doesn't help, and that mankind, in general, has already grown-out of such childish thoughts of physical gods (Shulchan Aruch Y.D. 146). Accordingly, you need not break the idol, but I believe the law obligates to pass it over to the National Antiquities Authority.