Active learning ideas
Faults and folds are the visible scars of tectonic movement. In this topic, students learn to classify these structures with precision, distinguishing between normal, reverse, and strike-slip faults, as well as anticlines and synclines. This is a fundamental skill for the OCR A-level, requiring students to link specific geometries to the tectonic regimes that produced them (e.g., extension vs. compression).
Activity 01
Using 'fault blocks' (wooden or foam blocks cut at angles), students model different fault types. They must move the blocks to show tensional and compressional movement and identify the 'hanging wall' and 'footwall' for each.
How are normal and reverse faults distinguished?
Activity 02
Stations show photos and diagrams of various folds (symmetrical, asymmetrical, recumbent). Students move between stations to identify the axial plane and limb dip, and then sketch how these would look on a flat map.
What tectonic forces create anticlines and synclines?
Activity 03
Groups are given a map with several faults and folds. They must work backwards to determine the sequence of tectonic forces (e.g., 'first it was squeezed, then it was pulled apart') that created the complex pattern.
How can fault movement be measured in the field?
A few notes on teaching this unit
Watch Out for These Misconceptions
An anticline is always a hill and a syncline is always a valley.
Folds refer to the 'age' and 'dip' of the rock layers, not the surface topography. Erosion can turn an anticline into a valley (an anticlinal valley). Comparing a structural map to a topographic map helps students see the difference.
The 'hanging wall' is always the one that moves.
Both sides of a fault move relative to each other. The terms 'hanging wall' and 'footwall' are just names based on the geometry of the fault plane. Using a 'tunnel' analogy (where you walk on the footwall and hang a lamp on the hanging wall) clarifies the naming convention.
Methods used in this brief
Deformation of Rocks
Analyse how rocks respond to tectonic stress through brittle and ductile deformation. Investigate the factors that influence rock behaviour, including temperature, pressure, and strain rate.
8 methodologies
Interpreting Geological Maps
Develop the spatial skills required to read and interpret geological maps and cross-sections. Students will deduce geological histories and calculate true dip and strike from map data.
8 methodologies