Horst is a feature associated with?

Analyze the question: The question asks which type of mountain a horst is associated with. This is a landform question on earth movements and faulting.

Explain the concept: When the Earth's crust is put under tension or compression, it can crack along lines of weakness called faults. Faulting produces these features:

• Horst: a block of land that is raised between two parallel faults.
• Graben (rift valley): a block of land that has sunk between two parallel faults.

Step-by-step solution:

1. Tensional or compressional forces create parallel faults in the crust.
2. The central block stays up, or is pushed up, while the side blocks drop down.
3. The raised block is the horst, and it forms what we call a block mountain (also called a fault-block mountain).
4. Check the other options: • Volcanic mountain: formed by lava and ash, such as Mt. Cameroon. It is not related to horsts. • Residual mountain: formed by erosion that leaves a resistant remnant behind, such as the Jos Plateau inselbergs. It is not related to horsts. • Fold mountain: formed by compression that bends rock layers into folds, such as the Alps and Himalayas.

Examples: The Vosges and Black Forest in Europe are horsts. The Ruwenzori Mountains in East Africa are also a classic block mountain.

Exam tip: Remember "Horst = Higher". Horst is the raised block, and graben is the grave (sunken) block. Whenever you see horst, think block mountain, and when you see graben, think rift valley.