Answer:
Syncline
Step-by-step explanation:
Synclines are the down folds that are constructed due to the compressive forces acting on a layer from both sides. It usually occurs in size ranging from a microscopic scale to a large megascopic scale. The oldest rocks are present at its outermost limb and the rocks become gradually younger toward its hinge area.
In an outcrop, the syncline and the anticline, both form simultaneously. The limbs that dip towards the trough of the fold indicate a syncline whereas the limbs that dips towards the crest are the anticline. The variation in the shape of these foldings (anticline and syncline) depends upon the intensity of the force.