The fieldwork

The area around Jumilla consisted of wide plains and mountains. One of the highest mountains in the region is this one, called the Sierra del Buey. It's peak is about 700 meters higher than the surrounding plains.

The Sierra del Buey is a so called cuesta. Cuestas are characterised by hardrock covering softer types of rock. When the hardrock is tilted due to tectonic forces, parts of the hardrock will be eroded, creating a cuesta-front with a steep slope.

This is well visible at the Sierra del Buey. When  you move your mouse over the image you'll see a cross-section of the mountain. It shows S-shaped folds in the rock-layers. Numbers 3 and 4 are layers of hard rock. Therefore is slope at the face of the mountain is quite steep. The layers with the numbers 1 and 2 are much softer. That is why the slope isn't that steep.