 Core samples were collected by researchers Doheny, Droste, and Shaver from the Indiana Geological Survey and Indiana University in 1975.The researchers catalogued a stratum of fossil sediment containing dolomite (calcium magnesium carbonate) and subsequently described its distribution from an origin in Northwestern Indiana, through veins to northeastern Indiana with varying thickness, erosion, and displacement by other strata along the way.Termed the “Milan Center Dolomite Member”, the name was taken from “Milan Center Township”, in which the Woodburn Quarry was located.