In a horizontal fold or non-plunging fold, the underlying rock layers are exposed on the surface as horizontal stripes. These might simply be confused as tilted rocks and not a fold without other information about the rocks under the ground. This can make the fold a bit easier to identify on the surface. Synclines can also be valleys, hollows between upraised anticlines. Normally the presence of anticlines and synclines is not so obvious.
Erosion usually wears away any rises or valleys to a flat plain.
In these cases, it's important to measure the dipping angle of exposed rocks to determine the type of fold. I will cover how to measure dip in rocks in a later article. Sometimes a fold dips more sharply on one limb than on the other. When this happens it is referred to as an asymmetrical fold . Asymmetrical folds result from unequal ammounts of pressure being applied to the rocks, causing one side to bend more steeply than the other side.