QUINCY, Ill. (AP) — Excavation work at the site of a new western Illinois jail has turned up some bones.

The Quincy Herald-Whig reports the grounds of the Adams County Courthouse was the original site of Quincy’s first cemetery. A ground-sounding process using radar to search for an estimated 15 to 20 graves on the property began Monday. The full excavation process could take up to two weeks.

Adams County Coroner Jim Keller says the bones have not yet been identified and few specifics are available.

The excavation is required for historical preservation purposes before any construction work can begin on the new Adams County Jail.

All bones discovered will be sent to Loyola University Chicago for preservation instead of being reburied locally. Then the search for descendants will begin.