The potential of Ojo de Valjunquera cave (NE of Iberia) sediments for paleoflood reconstructions
[EN] Speleothems and detrital sequences are excellent archives of past flood events but are still poorly exploited. In this study we evaluate the potential of the Ojo de Valjunquera cave for the study of past floods based on geomorphological, topographical, hydrological, and chronological data. The...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/259312 |
| Acceso en línea: | http://hdl.handle.net/10261/259312 |
| Access Level: | acceso abierto |
| Palabra clave: | Paleoflood Stalagmites Iberian Range Moncayo Cave sediments |
| Sumario: | [EN] Speleothems and detrital sequences are excellent archives of past flood events but are still poorly exploited. In this study we evaluate the potential of the Ojo de Valjunquera cave for the study of past floods based on geomorphological, topographical, hydrological, and chronological data. The cave presents two pseudo-horizontal cave levels. The lower presents a main horizontal conduit and six siphons. This level is connected to the upper one by shafts and ramps that favours the water level rise during rainfall events. The upper level is characterized by a major presence of speleothems and detrital sequences compared to the lower level. Current observations indicate that water can rise ~9 m in some cave sectors during rainfall episodes >60 mm, although the hydraulic head rise is not homogeneous along the cave, depending of section's morphology. The stalagmites and detrital sequences hosted in the upper gallery most likely contain evidence of extreme events of rainfall. However, geomorphological and sedimentological evidences also suggest that cave outlet could be blocked in the past by sediments, favouring the water rise of regular floods to high places not usually affected by floods. The detrital sequences located in lower positions respect to the cave entrance show a major proportion of sand than those located in the higher sectors related to the energy of the waters during the flood. Stalagmites show clean carbonate alternated with well-defined detrital layers. These detrital layers vary in thickness; the thin ones are related to small floods, whereas the thicker ones are related to large floods. Two important historical floods (1709 and 1755 CE) occurred in the area that coincide with distinct detrital layers recorded in the stalagmites. All these observations suggest that Ojo de Valjunquera cave contains an important paleoflood archive base on speleothems and detrital deposits during the Holocene. |
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