How Geology Shapes Our Coasts

Understanding coastal landscapes The role of rock types and weathering Year 9 Geography

What Are Coasts?

The meeting point between land and sea Dynamic environments constantly changing Shaped by waves, tides, and weather Home to diverse ecosystems and human settlements

Think About It

Why do some coasts have high cliffs while others have gentle sandy beaches? What might cause these differences?

The Power of Geology

Different rock types create different landforms Hard rocks form cliffs and headlands Soft rocks create bays and beaches Rock structure affects erosion patterns

Hard Rocks vs Soft Rocks

{"left":"Granite, basalt, limestone\nResistant to erosion\nForm steep cliffs and headlands\nCreate dramatic coastal features","right":"Chalk, clay, sandstone\nEasily eroded by waves\nForm gentle slopes and bays\nOften create sandy beaches"}

Weathering Processes at Work

Weathering Investigation

Examine rock samples or photos Identify signs of different weathering types Record observations in your notebook Discuss findings with your partner

Wave Action and Erosion

Waves provide the energy for coastal erosion Hydraulic action - wave pressure in cracks Abrasion - waves throw rocks at cliffs Attrition - rocks wear each other down Corrosion - chemical attack by seawater

Key Concept

"The hardest rocks determine the shape of our coastline, while the softest rocks determine where the sea can advance inland."

Bringing It All Together

Geology provides the foundation Weathering weakens the rocks Wave action removes the debris Different rocks create different landscapes Understanding geology helps predict coastal change