The upfolded portion of a fold mountain is called_____?

The upfolded portion of a fold mountain is called an anticline. A fold mountain is a type of mountain that is formed when rock layers are subjected to pressure and folded. Anticlines are formed when the rock layers are folded upwards, creating an arch-like shape. The highest point of the anticline is called the crest, while the lowest point is called the trough. Anticlines can be found in many different types of rock formations and are often associated with oil and gas deposits, which can be trapped in the folds of the rock.