Symmetrical folds are also called normal folds or upright folds. In such a fold, axial plane is essentially vertical.

Flowage folding is principal process of folding in incompetent or weaker, plastic type of rocks such as clays, shales, gypsum and rock salt etc.

The Liddar Valley Anticline in Kashmir Himalayas is often represented as a classic example in that almost complete sequence of Palaeozoic Era is fully developed in this anticline.

Supratenuous folds show differences in thickness at crestal and trough regions, not induced by folding process but essentially due to erosional and depositional processes operating in folded regions.

Thickness of layers and nature of contact are important factors on which amount of slip depends. Thicker layer, greater is slip.

The plunge is measured like a dip of a bedding plane, both in terms of direction of plunge and degree of plunge.

Any fold in which fold axis is not horizontal, that is, it makes an angle with horizontal, may be described as a plunging fold.

The converging plates may be two continental plates, a continental plate and an oceanic plate or a continental plate and an island plate but not two oceanic plate.

The geosynclines serve as depositional fields to which sediments are derived by erosion of adjoining geanticlines and sediments get accumulated and compacted. This material is n compressed and uplifted in second stage of orogeny, which is mountain building activity, to gradually take shape of mountain systems.

The anticlines which signify larger bending and uplifting of strata on sub-continental scales are expressed by term Geanticlines.