Geological risk assessment of the area around the Tito Bustillo Prehistoric Cave. Human Heritage (UNESCO, 2008). Asturias, North of Spain

摘要

The massif of Ardines is an uplifted wave-cut platform developed over Upper Carboniferous limestones, and contains the Tito Bustillo and La Lloseta caves, two important prehistoric cave sites. The main geomorphological features are controlled by the structural pattern: sinkholes are aligned along fractures and they have an oval morphology and the San Miguel river valley flows parallel to the El Carmen-Collera fault. The geological and geomorphological characterization has been used as the basis for the protection area definition. The Natural Risk Index, NRI, has been used for determining the geological risk level in different zones of the study area and to propose the protection area in order to prevent and mitigate the level risk and to protect the cave and the rock mass containing it. The main geological risk affecting the Tito Bustillo cave is located in the blind valley of the San Miguel river, sinking into the cave it provoke the leakage of the farm activity products throughout the cave galleries. Furthermore, many sinkholes which they are other evident absorption zone of the karstic system, are included in the protection area. This method results significant for geological risk assessment and engineering geology, because it can be used in the planning and development of engineering works near of prehistoric caves, and it also can act as a useful tool for land uses management.