synclinal

Synclinal refers to a type of fold in rock strata characterized by an upfold or anticline surrounded by downfolds or synclines. More commonly, synclinal describes a downfold or trough in rock layers where the youngest strata are found at the center of the fold. This geological structure is the opposite of an anticline, which is an upfold.

Synclines typically form when tectonic forces cause the Earth's crust to buckle and bend. These forces can be compressive, pushing rock layers together, or tensional, pulling them apart. The resulting downward bending creates a concave shape when viewed in cross-section. Sediments often accumulate in the lowest points of synclines, which can lead to the preservation of younger rock layers.

The term synclinal is used in geology to describe the shape and structure of folded rock formations. Identifying synclines is important for understanding the geological history of an area, predicting the distribution of rock types, and locating potential resources such as oil, gas, and water, which can sometimes be trapped in the lower portions of these folds. The axis of a syncline is the line connecting the points of maximum curvature along the fold.