Geological methods applied to speleogenetical research in vertical caves: the example of Torca Teyera shaft (Picos de Europa, northern Spain)

摘要

Research in large vertical caves (shafts) is rare and usually restricted to speleological explorations because of difficult access. The systemic methodology of work in shafts has not been established. Picos de Europa massif, in the Cantabrian Mountains of Spain, has a spectacular development of shafts deeper than 500 m. One of them is Torca Teyera cave, which is 738 m deep and 4 km long. The present study established a methodology to characterize the geological and geomorphological aspects of this special group of caves and to identify the factors contributing to karst development. The research is multidisciplinary, needs data from the cave and the caves' surroundings and involves (1) the speleological cave survey at a 1:500 scale: the construction of a 3D model and morphometric analyses; (2) the geomorphological mapping on the cave survey at 1:500; (3) the geological and fracture mapping of the cave environment and cross section at 1:5.000; and (4) the comparison in stereographic projection of the obtained survey data and joint measures.