unconformity

Halite salt casts in mudshale (Twist Gulch Formation, Middle Jurassic; float near small copper mine in Salina Canyon, Utah, USA)
by James St. John

Well cuttings from the VanWinkle Unit # 1 petroleum well (west of Granville, Ohio, USA) 2
by James St. John

Precambrian-Cambrian nonconformity (Sawatch Sandstone over Pikes Peak Granite; Ute Trail, Manitou Springs, Colorado, USA) 3
by James St. John

Quartz paleopebbles (Stebbins Gulch, Geauga County, Ohio, USA) 1
by James St. John

Blow line & pit at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 1
by James St. John

Fort Payne Formation-Chattanooga Shale-Cumberland Formation; Burkesville West Rt. 90 roadcut, Kentucky, USA) 3
by James St. John

Fossiliferous asphaltic limestone (Buckhorn Asphalt, Middle Pennsylvanian; Buckhorn Asphalt Quarry, Oklahoma, USA) 3
by James St. John

geological bealach
by Ricky Cosmos

Geolograph at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA)
by James St. John

Straparollus planodorsatus (fossil gastropod) (Maxville Limestone, Mississippian; Pleasant Valley Limestone Quarry, Muskingum County, Ohio, USA) 3
by James St. John

Ohio Shale-Olentangy Shale disconformity (Upper Devonian; Highbanks Park, Lewis Center, Ohio, USA) 3
by James St. John

Upheaval Dome Trail, Canyonlands National Park, Utah
by Ken Lund

Composite ironstone concretion 5
by James St. John

Blow line & pit at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 3
by James St. John

Mississippian-Pennsylvanian unconformity (Rt. 16 roadcut northeast of Frazeysburg, Ohio, USA) 12
by James St. John

Alicia, Upheaval Dome Trail, Canyonlands National Park, Utah
by Ken Lund

Blow line & pit at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 6
by James St. John

Well head at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA)
by James St. John

Malachite mineralization at Salina Canyon angular unconformity (Sevier County, Utah, USA) 5
by James St. John

Well cuttings from the VanWinkle Unit # 1 petroleum well (west of Granville, Ohio, USA) 3
by James St. John

Pottsville Group over Maxville Limestone (Pleasant Valley Limestone Quarry, Muskingum County, Ohio, USA) 2
by James St. John

Columbus Limestone (Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 1
by James St. John

Angular unconformity - Flagstaff Formation over Twist Gulch Formation (Salina Canyon, central Utah, USA) 70
by James St. John

Weathered, oxidized pyrite (Columbus Limestone or Delaware Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 4
by James St. John

Angular unconformity - Flagstaff Formation over Twist Gulch Formation (Salina Canyon, central Utah, USA) 74
by James St. John

Bleeding unconformity (Chattanooga Shale over Cumberland Formation; Burkesville West Rt. 90 roadcut, Kentucky, USA) 7
by James St. John

Ohio Shale-Olentangy Shale disconformity (Upper Devonian; Highbanks Park, Lewis Center, Ohio, USA) 8 (Ljubomir Risteski photo)
by James St. John

Delaware Limestone over Columbus Limestone (Middle Devonian; Indian Village Canyon, Columbus, Ohio, USA) 6
by James St. John

Ohio Shale-Olentangy Shale disconformity (Upper Devonian; Highbanks Park, Lewis Center, Ohio, USA) 7 (Ljubomir Risteski photo)
by James St. John

Sandstone (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 4
by James St. John

Precambrian-Cambrian nonconformity (Manitou Limetone over Peerless Formation over Sawatch Sandstone over Pikes Peak Granite; Manitou Avenue roadcut, Manitou Springs, Colorado, USA) 3
by James St. John

Ohio Shale-Olentangy Shale disconformity (Upper Devonian; Highbanks Park, Lewis Center, Ohio, USA) 4
by James St. John

Sharon Sandstone (Lower Pennsylvanian; Mary Campbell Cave, Cuyahoga Gorge, Cuyahoga Falls, Ohio, USA) 2
by James St. John

Blow line & mudlogging gas detection equipment at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 1
by James St. John

Angular unconformity - Flagstaff Formation over Twist Gulch Formation (Salina Canyon, central Utah, USA) 4
by James St. John

Blow line & mudlogging gas detection equipment at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 2
by James St. John

Conglomerate (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 3
by James St. John

Old copper mine (Salina Canyon angular unconformity, Sevier County, Utah, USA) 6
by James St. John

Old copper mine (Salina Canyon angular unconformity, Sevier County, Utah, USA) 4
by James St. John

Drilling pipe at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 2
by James St. John

Sandstone (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 2
by James St. John

Conglomerate (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 7
by James St. John

Mississippian-Pennsylvanian unconformity ("Sharon" Conglomerate over Logan Formation; Jackson North roadcut, Ohio, USA) 7
by James St. John

Blow line & pit at VanWinkle Unit # 1 petroleum well (west of Granville, Ohio, USA) 1
by James St. John

Sandstone (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 7
by James St. John

Moellerina greenei (fossil charophyte oogonia) in fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 1
by James St. John

Halite salt casts in hematitic mudshale (Twist Gulch Formation, Middle Jurassic; float near small copper mine in Salina Canyon, Utah, USA) 1
by James St. John

Rip-up clasts in micaceous sandstone (lower Pottsville Group, Lower Pennsylvanian; Pleasant Valley Limestone Quarry, Muskingum County, Ohio, USA) 2
by James St. John

Halite salt casts in hematitic mudshale (Twist Gulch Formation, Middle Jurassic; float near small copper mine in Salina Canyon, Utah, USA) 4
by James St. John

Overturned crossbeds in sandstone (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 3
by James St. John

Plate 17A. Unconformity, channel in Chinle shale filled by sandstone of the Wingate sandstone
by egcd32

Malachite mineralization at Salina Canyon angular unconformity (Sevier County, Utah, USA) 2
by James St. John

Maxville Limestone (Mississippian; Pleasant Valley LImestone Quarry, Muskingum County, Ohio, USA) 1
by James St. John

Angular unconformity - Flagstaff Formation over Twist Gulch Formation (Salina Canyon, central Utah, USA) 37
by James St. John

Ohio Shale-Olentangy Shale disconformity (Upper Devonian; Highbanks Park, Lewis Center, Ohio, USA) 1
by James St. John

Sandstone (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 1
by James St. John

Conglomerate (Sharon Formation, Lower Pennsylvanian; Virginia Kendall Ledges, Ohio, USA) 1
by James St. John

Fossiliferous limestone (Columbus Limestone, Middle Devonian; Emerald Parkway roadcut, Dublin, Ohio, USA) 22
by James St. John

Drilling pipes at Hendren Century Farms # 2 petroleum well (north of Johnstown, Ohio, USA) 1
by James St. John

Fort Payne Formation-Chattanooga Shale-Cumberland Formation; Burkesville West Rt. 90 roadcut, Kentucky, USA) 2
by James St. John