In structural geology, a syncline is a downward-curving fold, with layers that dip toward the center of the structure. On a geologic map (or "in map view"), 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.

See also

• Anticline
• Ridge-and-valley Appalachians — With good bird's eye photo of a range of the types

Structural geology

Synklinale | Sünklinaal | Sinklinalo | Synklina | Sinklinala