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"By downward corrasion a stream cuts a steep-sided trench of its own width, but weathering, gravitation, and the wash of the rain widen it and make the sides sloping." a, a young V-shaped valley; b and c, deeper; d, flood-plain condition. -Dryer, 1901

Valley Development

"By downward corrasion a stream cuts a steep-sided trench of its own width, but weathering, gravitation,…

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection of hard layers and the retreat of the softer ones." -Dryer, 1901

Unequal Valley Development

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection…

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901

Usymmetrical Valley Development

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901