Geomorphological evolution and mapping of the littoral of Asturias and Cantabria (Northern Spain) in the area of El Pindal Cave: relations between coastline and karstic morphologies

Figures & data

Figure 1. Study area.

Extension of the study areas with the most relevant toponymy and cited in the article.

Figure 2. General sequence of marine erosional surfaces (rasas).

Idealized profile of the general sequence of erosive marine surfaces (rasas) corresponding to the study area located on quartzite and limestone substrate. The sections studied are marked with numbers and letters, which are represented on the hypsometric map within the main map (Fig. 1). The numbers on the steps indicate the heights above current sea level. Distribution of the main fractures (E-W and NNW-SSE).

Figure 3. Examples of rasas, indicators of sea-level and palaeographic changes. (A) Rasas eroded on quartzites. There is one below the village of Pimiango at 160–162 m, and another at 150 m (herb packages); they are separated by a glacis. (B) Rasas cut on limestones. The village of Buelna rests on the one at 40-42 m; the one behing the village, near the coast is at 30–32 m. (C) Rasas and caves in limestones,as seen from Los Bufones de Arenillas. Rasas of La Tejera (16 and 31 m) in the first plane and, at the far end, Castro Bellota (40 m). Caves at 2–3 m elevation (Present) and at various elevations in the cliff. (D) Caves of possible marine origin at 65–66 m (Early Pleistocene), when there was a marine connection between Ensenada de Novales and Pendueles beach. At that time, the Piedrallada and Catariello hills formed an island. (E) A current notch, indicator of sea level, at Playa Vidiago; note in the upper part, the superimposition on an older notch. (F) Notches in Playa de Borizu: a fossil notch at 10–11 m and a current one at sea level. (G) Narrow v-shaped valley at the present mouth of the Deva River, as seen from Bustio-Unquera. (H) Fossil valley: abandoned tract with a flat bottom and mature slopes, between Unquera and Pesués.

Photographs of the different indicators of the position of the sea level at the time of its formation. Erosive terraces (A, B and C), Caves (C and D), notches (E and F); G and H images of the fluvial capture of the Deva River at the height of Bustio (Asturias) and the Fossil Valley (Unquera-Pesués).

Figure 4. A general sequence of erosional marine terraces (rasas) and other paleo sea-level indicators at El Pindal-Tinas area.

Marine erosion platforms (Rasas) and indicators of old sea level positions in the El Pindal-Tinas area, indicating the localities where they are found.

Figure 5. Geomorphological map of the area surrounding El Pindal cave.

Geomorphological map of the El Pindal-Pimiango sector, with its explanatory legend, on a digital terrain model.

Figure 6. Fallen block in front of the entrance of El Pindal cave.

Example of the slipped block, in front of the entrance of the Cueva de El Pindal, indicating the heights of the notches, visors, caves and marine erosion surface (Rasa), from which the given values have been obtained on the sea cliff represented in Fig. 4. In blue the value of the displacement of the block.

Data availability statement

The scientific data obtained in this work are published in the text of the article. However, any extension or detail can be requested from the corresponding author.