Part 7 CHANNEL FORM AND PATTERNS

Antecedent and Superimposed Streams An antecedent stream is one whose path of flow within a valley was established before the mountainous structure was uplifted Superimposed streams is one whose valley and direction of flow were developed much later than the underlying structure, and the river possessed sufficient stream power to cut through these underlying structures.

Common drainage patterns that are structurally controlled

Water gaps through resistant ridges in regions with antecedent drainage, where the river course was established over a pre- existing erosion surface

Wind Gaps are notches in resistant bedrock ridges that were formerly water gaps when there was insufficient stream power to complete the down cutting process. These are also known as abandoned drainages, stream capture, or stream piracy.