Dark bluish-gray argillite (Metamudstone Member of the Cid Formation) is quarried by Jacobs Creek Stone Company from slate belt rocks in Montgomery and Davidson Counties, NC. Click here for the location of this operation plotted on the 1985 Geologic Map of North Carolina. This operation is shown as the blue dot just southeast of Jackson Hill.
The stone's smooth natural cleavage allows it to be used extensively in flooring, stair treads, borders and window sills. Many public school window sills in North Carolina are made from this stone. Click here for rock properties and chemistry MS Excel¿ file).
Examples of where this stone can be seen include: Duke University's Fuquay School of Business, R. B. House Library at the University of North Carolina at Chapel Hill (under construction in 2002), Kings Mountain National Military Park (visitor center and exhibits), and the NC Welcome Center on Interstate 85 at the NC-SC border.
The following illustrates the process of mining and finishing the argillite. The process begins when the argillite is mined by a front end loader from fairly small open cuts (below). The process begins by loading large slabs of argillite into a small dump truck for transport to the splitting area. The argillite dips toward the left in the photograph (toward the northwest).
Mining the argillite and loading it on a small dump truck for transport to the splitting area.