Syncline

In structural geology, a syncline is a fold with younger layers closer to the center of the structure. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed smaller folds. Synclines are typically a downward fold (synform), termed a synformal syncline (i.e. a trough), but synclines that point upwards can be found when strata have been overturned and folded (an antiformal syncline).Syncline exposed in Sideling Hill roadcutSnow-dusted syncline in Provo Canyon, UtahRoad cut near Fort Davis, Texas showing a synclineRainbow Basin Syncline in the Barstow Formation near Barstow, CaliforniaSyncline in the lower parking lot of Calico Ghost Town; the ductile folding is at the base and the brittle is above.Synclinal fold in Silurian Wills Creek Formation or Bloomsburg Formation at Roundtop Hill (Maryland)East wall of Bear Valley Strip Mine, near Shamokin, PennsylvaniaSyncline in Navajo Sandstone, Upheaval Dome, Canyonlands National Park, UtahSatellite view of part of New Zealand's Southland Syncline, showing parallel folds running northwest-southeast In structural geology, a syncline is a fold with younger layers closer to the center of the structure. A synclinorium (plural synclinoriums or synclinoria) is a large syncline with superimposed smaller folds. Synclines are typically a downward fold (synform), termed a synformal syncline (i.e. a trough), but synclines that point upwards can be found when strata have been overturned and folded (an antiformal 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.