Exercises: Relief and landscape

Name four external geological agents that shape the relief and give an example of a landform created by each one.

Explain the difference between erosion, transport and deposition, and order them as they occur in landform shaping.

State whether these landforms were mainly shaped by water, ice or wind: a U-shaped valley, a dune, a river canyon and a moraine.

Two regions with the same climate have very different landscapes because one consists of limestone rock and the other of granite. Explain how lithology (rock type) influences landform development and what characteristic relief limestone typically creates.

Relief is also a resource. Describe two economic uses of relief (for example, tourism or agriculture) and a risk associated with each.

Look at the cross-sectional profiles of the two valleys in the diagram, marked with ?. Identify which is a river valley and which is a glacial valley, explain which agent shaped each one, and what differences in shape allow them to be distinguished.

A municipality with an old mining basin in economic decline has a unique karst landscape with prehistoric caves, tectonic folds of great educational value, and several threatened botanical species. The city council is debating between two protection designations:

• Option A: Declare the area a National Park with strictly restricted access for scientific research.

• Option B: Apply for its declaration as a UNESCO Global Geopark.

1. a) Justify why the Geopark model is better suited to this case than the National Park model if the goal is to reconcile the protection of geological heritage with the socioeconomic development of the local population.
2. b) Design two specific geotourism management measures that the geopark should implement so that public visits do not alter or degrade the karst cavities.

In Las Médulas (León), Roman mining transformed the landscape through the technique of ruina montium (violent injection of pressurised water into galleries to collapse hillsides), generating alluvial fans of boulders, mudflats, and the natural dam of Lake Carucedo. Today it is a protected landscape designated as a UNESCO World Heritage site.

1. a) Analyse human intervention as an external geological agent in Las Médulas, identifying the stages of erosion, transport, and sedimentation artificially caused by the mining technique.
2. b) A current mining company requests permission to open-pit mine a nearby pristine valley, arguing that "human activity creates landscapes that in the future will also be considered historical heritage like Las Médulas". Technically refute this argument by comparing the rate of landscape alteration, the toxicity of modern techniques, and the possibility of ecological regeneration.

Imagine a geological and topographical cross-section running across the Iberian Peninsula from north to south: the Cantabrian Mountains, the Douro Basin, the Central System, the Tagus Basin, and the Betic Cordillera.

1. a) During the Alpine orogeny, why did the ancient Hercynian basement of the central peninsula respond by fracturing into uplifted blocks (horsts) and down-dropped blocks (grabens), whereas on the edges (Cantabrian and Betic ranges) large folded mountain chains formed? Justify your answer based on the mechanical behaviour of the materials in each area.
2. b) Predict the origin and geometric arrangement (horizontal or folded) of the materials that fill the Douro and Tagus basins, deducing which mountain ranges they come from and what geological process caused their accumulation.

Unit challenge. Imagine that you work as a geoscience communicator and must reveal the origin of your region's landscape. Your mission is to write a short report (maximum $1$ page) that reconstructs the geological history of your surroundings by combining official cartography and landscape interpretation.

1. Cartographic exploration: Access the continuous GEODE viewer of the Instituto Geológico y Minero de España (IGME) and locate your municipality. Note down the two main lithologies present and their geological age in millions of years (for example, limestone strata from $85,5\text{ Ma}$ ago).

2. Geomorphological analysis: Open the Iberpix viewer of the Instituto Geográfico Nacional (IGN) and observe the current relief. Explain how the arrangement of rocks and erosive agents (such as rivers or weathering) have shaped the landforms visible today.

3. Cross-section and historical synthesis: Design a schematic synthetic geological cross-section of the terrain. Arrange the events chronologically using stratigraphic principles (superposition of strata, deformation, and cross-cutting relationships), concluding with the shaping of the present-day relief.

Assessment criteria:

• Thoroughness in obtaining and interpreting lithological and chronological data from official viewers (IGME/IGN).

• Accuracy in applying the fundamental principles of relative dating to the geological cross-section.

• Consistency in justifying how tectonic and lithological history determines contemporary relief.