Noun
A synclinal fold.
Source: Webster's dictionaryA diagram of folds, indicating an anticline and a syncline Even higher pressures and temperatures during horizontal shortening can cause both folding and metamorphism of the rocks. Source: Internet
Geologically, the Lake Ladoga depression is a graben and syncline structure of Proterozoic age ( Precambrian ). Source: Internet
There is some indication that the Agusan Valley occupies a broad syncline between the central mountains and the east-coast mountains. Source: Internet