Herrin coal pinchout/cutout
In parts of Hopkins, Union, and Webster Counties in western Kentucky, the Herrin (W. Ky. No. 11) coal pinches out or is truncated by limestone and shale. The edge of the coal in these areas is commonly brecciated and mineralized (with calcite cements), and has been termed the ragged edge of the Herrin coal (Hower and others, 1987; Hower and Williams, 2001; O'Keefe and others, 2008). In some areas, the coal thins lateral to the ragged edge, whereas in other areas, normal coal height is truncated by limestone and shale cutouts. The large area of Herrin pinchout and cutout is not part of the well-known Anvil Rock and Walshville channels, which cut the Herrin coal in parts of southern Indiana and Illinois. The Walshville channel can be traced for more than 130 miles (Hopkins and others, 1969). At least in some of these areas, the “ragged edge” is a cutout of the coal.