Interlocking Spurs and V-Shaped Valleys

Key Topics

• River Landforms in the Upper Course
• Exam Questions Related to River Landforms
• Formation of V-Shaped Valleys
• Formation of Interlocking Spurs

Exam Question Types

• Describe formation of v-shaped valleys and interlocking spurs
• Label and annotate photographs or diagrams
• OS map skills related to river landforms

Formation of V-Shaped Valleys and Interlocking Spurs

Step 1: Initial River Characteristics

• Located in the upper course of the river
• Low discharge and low volume of water (similar to a stream)
• Surrounded by steep valley sides
• River's energy mainly used to overcome friction
• Hydraulic action deepens the channel through vertical erosion

Step 2: Geological Influence

• Upper course composed of hard, resistant rock (e.g., granite, slate)
• Freeze-thaw weathering: water enters cracks, freezes at night, expands cracks, thaws during the day
• Over time, leads to a wider river channel and steep v-shaped valley profile
• Weakened rock breaks into smaller material, shifts into the river, transported downstream

Step 3: Path of the River

• River winds around obstacles of hard rock
• Takes the easiest route possible
• Creates interlocking spurs, where land criss-crosses

Visual Identification

• Diagrams and photographs can show interlocking spurs and v-shaped valleys
• Interlocking spurs identified by criss-crossing valley sides
• Photographs may show the river carving out the landscape, creating the v-shaped profile

OS Map Skills

• Identifying upper course of a river
• Evidence of interlocking spurs and v-shaped valleys
• Contour lines on OS maps indicate steep valley sides
• Close-packed lines suggest possible presence of these landforms