Daniel Ballesteros

The Picos de Europa National and Regional Parks

The E–W trending Cantabrian Mountains, with peaks more than 2,600 m a.s.l., are located along the northern coast of the Iberian Peninsula. After the development of south-verging structures during the Alpine Orogeny, the Cantabrian Mountains were arranged as an asymmetrical relief deeply dissected by the fluvial network, with steep rivers flowing into the Cantabrian Sea in the north and less steep rivers draining towards the Duero Tertiary Basin to the south. The area shows a high geomorphic diversity, including relict Quaternary glacial and periglacial landforms, as well as features related to slope instability, fluvial and karstic processes. This work summarizes the geomorphological features of two different protected areas of the Cantabrian Mountains designated as Picos de Europa: the Picos de Europa National Park and the Picos de Europa Regional Park. Both are representative areas of the high-mountain landscapes of the northern and southern sectors of the Cantabrian Mountains. Moreover, the former hosts good examples of underground alpine karst.

New evidence of sea-level lowstands and paleoenvironment during MIS 6 and 4 in the Cantabrian coastal karst: The Cobiheru cave (North Iberia)

The geomorphological evolution of the Cobiheru Cave shows the influence of the non-carbonate coastal mountain ranges on coastal karst evolution, as well as the temporal distribution of the cold-adapted fauna sites in the Cantabrian Coast. Geomorphological observation and U/Th dating lead to the construction of an evolution model. The model comprises two episodes of cave deposition occurred at ca. 60–70 and 130–150 ka, linked to cold climate conditions, global sea-level lowstands and the erosion of alluvial fans that covered the karst. Moreover, the comparison between the Cobiheru record and some raised beaches identified in previous studies sets the beginning of the sea-level lowering in the Cantabrian Sea during the MIS 5-4 transition. Two palaeoenvironments are inferred based on finding Equus ferus and Elona quimperiana. A wet deciduous forest would have been developed on the emerged marine terrace of the Cobiheru Cave since at least the Middle Pleistocene, and an open landscape with scarce vegetation would have been present at ca. 65 ka. The erosional event identified in the Cobiheru Cave helps to understand the temporal distribution of cold-adapted mammals located in the Asturias region. The probable sites of cold-adapted fauna developed in caves and alluvial fans would have disappeared after 65 ka. Therefore, palaeontological and palaeoclimate research based on cold-adapted mammals suggests the occurrence of an hiatus in the palaeontological record prior to 50 ka. This article is protected by copyright. All rights reserved.

Geoheritage and Geodiversity Evaluation of Endokarst Landscapes: The Picos de Europa National Park, North Spain

The endokarst presents a spectacular Geoheritage involving many singular features with thousands to millions years in age. The Picos de Europa National Park has one of the most important karst landscapes in the world. The endokarst of Picos de Europa shows high natural, scientific, and cultural values mainly related to cave features, with a spectacular vertical development (14 % of known world caves deeper than 1 km), the presence of geomorphological and sedimentary records related to the Quaternary evolution of the Cantabrian Mountain Range, and the traditional and sport uses of the cavities. The aim of this work is to inventory and to evaluate the Geoheritage and Geodiversity of the endokarst of Picos de Europa National Park combining speleological data, field work, and geomorphological mapping from nine selected caves. As a result, the Picos de Europa Geodiverstiy features show a high variability: 75 different natural features have been recognized with a density ranging from 0.3 to 1.1 different features per cm2 of cave area.

Cliff Coast of Asturias

The Principality of Asturias (or simply Asturias) is a region located in the North of Spain (SW of Europe) limited by the Cantabrian Sea in the North and the Castilla y Leon, Cantabria and Galicia regions in the South, East and West respectively. The Asturias Coast represents around 30% of the Cantabrian Coast, the northern limit of the Iberian Peninsula, and is surrounded by the Cantabrian Sea. This sea represents the transition of the Atlantic Ocean to the Biscay Gulf, between Spain and France. Towards the South, the Cantabrian Coast is limited by the Cantabrian Mountains, up to 2,648 m altitude, which axis is located only at 20–50 km from the sea.

Influence of the Rivers on Speleogenesis Combining KARSYS Approach and Cave Levels. Picos de Europa, Spain

The influence of rivers on speleogenesis is studied analyzing the cave levels located in the underground drainage areas related to two fluvial basins. Cave levels are analyzed through their vertical distribution profiles. The underground limits of the fluvial basins are defined using a 3D geometric model of the karst aquifer established according to the KARSYS approach. The aim of this work is to analyze the influence of the rivers on cave evolution using cave morphology. The study area corresponds to the Western and Central massifs of Picos de Europa (Northern Spain), with 214 km of cave conduits up to 1.6 km vertical range. As a result, we established two sequences of development of the cave levels related to the differences of the incision rate of the Cares and Dobra Rivers, and the partial capture of the Western Massif by the Cares River.

Environmental Study of Cave Waters: A Case Study in Las Herrerías Cave (Llanes, Spain)

Las Herrerias Cave (Llanes, North Spain) is a relevant cave due to its cave palaeolithic paintings. It was declared of Good Object of Cultural Interest by the Asturias Regional Government. It is located in a karst Carboniferous aquifer which surface involves farming, livestock and tourist use, as well as a discrete mining activity and an old quarry converted into a waste area above the karst massif. A hydrogeological research was carried out from 2007 to 2010 focusing on the impact of land use on the cave. The aim of this work is to highlight the importance of using hydrochemistry monitoring to determinate the impact of the land use on cave waters. Several sampling campaigns of rainfall, the waters inside and outside the cave and El Bolau spring were carried out. A sampling device was installed inside the cave to collect discrete samples of dripwater each 48 h in 1.5 l bottles. The array contains 24 bottles and was deployed for 48 days intervals. Results evidence that calcium bicarbonate is the dominant chemical component in all the sampled water. Some of them, collected under the waste area, show high values in NO3 −, Ba2+, TOC, K+, SO4 2−, Silicium, Fe, Si, PO4 3−and Sr2+, being indicative of an adverse effect on the quality of drip water.

Geomorphology and Structural Control in Caves: a Research in Torca Teyera (Picos de Europa, NW Spain)

Research in caves is rare and restricted to speleological explorations. Picos de Europa Massif shows a spectacular development of vertical caves deeper than 500 m. Torca Teyera is a 738 m-deep and 4 km-long vertical cave. The aim of this work is to establish a methodology to characterize the geological and geomorphological aspects of this special group of caves, as well as to identify the factors conditioning karst development. The research involves (1) the cave survey at a 1:500 scale and the construction of a 3D model, (2) the geomorphological mapping on the topographical survey, (3) the geological mapping of the cave environment at 1:5000 and (4) the comparison in stereographic projection of the obtained survey data and joint measures.