Rockford Limestone over Maury Shale (Lower Mississippian; Burkesville West Rt. 90 roadcut, Kentucky, USA) 3
Dolostone in the Mississippian of Kentucky, USA. (geology hammer for scale)
This is the Rockford Limestone, a relatively thin interval of dolostone. Very weathered surfaces are yellowish-brown to brown in color. Fresh, crack surfaces are light to medium gray in color. At this site, the Rockford has silicified fossils (e.g., crinoid stems).
The overlying gray shales are part of the Fort Payne Formation. The underlying unit is the Maury Shale.