Solution:Recumbent fold has an essentially horizontal axial plane. Linear, fold axial plane oriented at low angle resulting in overturned strata in one limb of the fold. When the two limbs of a fold are essentially parallel to each other and thus approximately parallel to the axial plane, the fold is called isoclinal.
Many folds are distinctly linear; that is, their extent parallel to the axis is many times their width. Some folds, however, are not linear but are more or less circular in plan. A dome is such a fold that is convex upward; this means that its strata dip outward from a central area. A basin is a circular fold that is concave upward-i.e., the strata dip inward toward a central area.
