In structural geology, a syncline is a downward-curving fold, with layers that dip toward the center of the structure. On a geologic map, synclines are recognized by a sequence of rock layers that grow progressively younger, followed by the youngest layer at the fold's center or hinge, and by a reverse sequence of the same rock layers on the opposite side of the hinge. If the fold pattern is circular or elongate circular the structure is a basin. A notable syncline is Wyoming's Powder River Basin. Folds typically form during crustal deformation as the result of compression that accompanies orogenic mountain building. A spectacular example of a perched syncline, the highest in Europe, is Saou, in the Alpine foothills of south-eastern France.
Gallery
 Syncline, Torres del Paine National Park, Chile |
 Snow-dusted syncline in Provo Canyon, Utah |
 Road cut near Fort Davis, Texas showing a syncline. |
 Graphic syncline depiction |
 Anticline with syncline on the right - USGS |
 Rainbow Basin Syncline near Barstow, California |
 An image of a large syncline seen from space]] |
See also
- Anticline
- Ridge-and-valley Appalachians — With good bird's eye photo of a range of the types
