Syncline

On a geologic map, synclines are recognized as a sequence of rock layers, with the youngest at the fold's center or hinge and with a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate, the structure is a basin. Folds typically form during crustal deformation as the result of compression that accompanies orogenic mountain building. ==Notable examples==

• Powder River Basin, Wyoming, US • Sideling Hill roadcut along Interstate 68 in western Maryland, US, where the Rockwell Formation and overlying Purslane Sandstone are exposed • Forêt de Saou syncline in Saou, France • Southland Syncline in the southeastern corner of the South Island of New Zealand, including The Catlins and the Hokonui Hills • Strathmore Syncline, Scotland • Wilpena Pound, Flinders Ranges, South Australia • Fort Valley, Shenandoah County, Virginia • Hondo Syncline in the Picuris Mountains of New Mexico, an example of an overturned syncline • Afikpo syncline, Nigeria • Table Mountain, South Africa ==Gallery==

File:Sideling Hill cut MD1.jpg|Syncline exposed in Sideling Hill roadcut File:Provo Canyon syncline.jpg|Snow-dusted syncline in Provo Canyon, Utah File:Syncline.JPG|Road cut near Fort Davis, Texas showing a syncline File:Rainbow Basin.JPG|Rainbow Basin Syncline in the Barstow Formation near Barstow, California File:SynclineCalico.JPG|Syncline in the lower parking lot of Calico Ghost Town; the ductile folding is at the base and the brittle is above. File:Roundtop Hill outcrop1.jpg|Synclinal fold in Silurian Wills Creek Formation or Bloomsburg Formation at Roundtop Hill (Maryland) File:Bear Valley east wall.jpg|East wall of Bear Valley Strip Mine, near Shamokin, Pennsylvania File:Upheaval Syncline campsite.jpg|Syncline in Navajo Sandstone, Upheaval Dome, Canyonlands National Park, Utah File:The Catlins.jpg|Satellite view of part of New Zealand's Southland Syncline, showing parallel folds running northwest–southeast File:Wilpena Pound - Aerial View.jpg|Wilpena Pound, a synclinal basin in the Flinders Ranges of South Australia ==See also==