Using a field sketch to teach coasts
Introduction
Coasts are a popular option in GCSE specifications. A useful teaching technique is to draw and label a field sketch to interpret the coastal features seen in a photograph. Annotations can be used to identify the landforms in the photo and explain the processes and factors that have led to their formation. In this example, the headland of Logan Rock and the sandy bay of Pedn Vounder Beach in Cornwall provide examples of the landforms created when waves erode a coastline consisting of resistant and less resistant rocks.
Using the PowerPoint presentation and PDF, students could work individually or collaboratively to answer the question Can you identify the landforms seen in this photo and explain the different coastal processes which have affected their formation, using an annotated field sketch? Labels and boxes are provided to show the landforms and highlight the processes responsible for the development of the coast. Erosion by wave attack, and the role of weathering, rock type and types of waves are highlighted. These resources support both the initial teaching of coasts and the revision of key terminology and concepts for examinations.
The coastline at Logan Rock is formed of Land’s End granite. Granite is a very resistant rock, formed of interlocked crystals, but is dominated by a network of vertical and horizontal joints formed by cooling and contraction. This rectangular pattern of jointing breaks up the granite and has been weathered over thousands of years by freeze-thaw. Prominent outcrops of rocks on the cliffs look like they are made of building blocks and are called Tors. Sometimes, large rocks that are delicately balanced will rock, and are known locally as Logan stones.
After the granite formed in this area, hot fluids and gases were forced through the joints and large faults caused by earth movements, altering and weakening the rock. Waves eroded these weaker areas of rock creating deep clefts. Eventually these areas of weaker rock were enlarged into bays.
About the Author
Juliette Zuvic, Geography teacher
Juliette graduated from the University of Southampton with a BSc Geography with Oceanography. She has worked for an environmental consultancy company supporting the rivers and coastal team and recently worked at the South Atlantic Environmental Research Institute. Juliette qualified with a PGCE from the University of Exeter and has worked as a secondary school Geography teacher for nine years. She enjoys combining photography into geographical teaching resources and plans to share items useful to fellow geography teachers.
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