James St. John:
Chert nodules in limestone (Casey Member, Boyle Formation, Middle Devonian; Drowning Creek West roadcut, far-western Estill County, eastern Kentucky, USA)
James St. John:
Stylolite in limestone (Boyle Formation, Middle Devonian; Drowning Creek West roadcut, Kentucky, USA)
James St. John:
Portwood Member over the Boyle Dolomite (Middle Devonian; Waco roadcut, Madison County, Kentucky, USA) 1
James St. John:
Portwood Member over the Boyle Dolomite (Middle Devonian; Waco roadcut, Madison County, Kentucky, USA) 2
James St. John:
Boyle Formation over the Estill Shale (Devonian over Silurian; Drowning Creek West roadcut, Madison County, Kentucky, USA) 1
James St. John:
Boyle Formation over the Estill Shale (Devonian over Silurian; Drowning Creek West roadcut, Madison County, Kentucky, USA) 2
James St. John:
Boyle Formation over the Estill Shale (Devonian over Silurian; Drowning Creek West roadcut, Madison County, Kentucky, USA) 3
James St. John:
Portwood Member of the New Albany Shale over the Boyle Formation (Middle Devonian; Drowning Creek East outcrop, Estill County, Kentucky, USA) 1
James St. John:
Portwood Member of the New Albany Shale over the Boyle Formation (Middle Devonian; Drowning Creek East outcrop, Estill County, Kentucky, USA) 2
James St. John:
Portwood Member of the New Albany Shale over the Boyle Formation (Middle Devonian; Drowning Creek East outcrop, Estill County, Kentucky, USA) 3
James St. John:
lower Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 1
James St. John:
lower Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 2
James St. John:
Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 1
James St. John:
Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 2
James St. John:
Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 3
James St. John:
Boyle Formation (Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 4
James St. John:
Ambocoelia brachiopods in shale (lower Boyle Formation, Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 1
James St. John:
Ambocoelia brachiopods in shale (lower Boyle Formation, Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 2
James St. John:
Ambocoelia brachiopods in shale (lower Boyle Formation, Middle Devonian; Emmanuel Baptist Church roadcut, Estill County, Kentucky, USA) 3