points it out. Visiting Bromberek Flagstone in Joliet, I mention to the quarry’s owner, Larry Bromberek, that I expected a vast, yawning chasm, not a flat grayish-white moonscape. Dressed in shades of faded blue—T-shirt, jeans, and a button-down shirt, with dust-covered black shoes—Bromberek, 70, nods and gestures to the north side, then takes me over to an eight-foot-high cross section of the earth. As Interstate 80 grumbles and thrums nearby, he identifies the sundry layers revealed by 30 years of mining. Up top is the overburden, a collection of soil, sand, silt, and grit. Below that are several staggered levels of yellowish rock, a fragment of the Sugar Run dolomite formation that rests beneath the area. It’s commonly known as Joliet-Lemont
