SOUTH BEND, Ind. (AP): Volunteers in South Bend have spent this week digging into the past of a well-known local mansion.

The archaeological investigation at the Oliver Mansion aims to dig to the level that would have been the surface in the late 19th century. Mansion Curator Kristie Erickson says the goal is to learn from objects left in the past.

The South Bend Tribune reports (http://bit.ly/1t6rCBl ) volunteers have found bits of field stone and other construction material suggesting that the area might have been a dump site for debris during the mansion's construction in 1897.

Volunteers are using toothbrushes, cotton swabs and water to carefully clean each item found during the dig. The items will be stored in bags marked with information on where they were found and will be studied later.