L’avenc de sa Casilla (El Pilar de la Mola, Formentera)

[eng] In this work, the topographic survey and characteristics of a cave with a toponym that recalls a profession that has faded in time, that of road laborers, is made known. It is closely linked to the location of a chasm right on the sidewalk of the road to la Mola. The cave dev...

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Detalles Bibliográficos
Autores: Gràcia, Francesc, Enseñat, Juan José, Santandreu, Gabriel, Lago, Carlos Vicente, Ramiro, Sergi, Vicens, Damià, Fornós, Joan J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad de las Islas Baleares
Repositorio:Biblioteca Digital de les Illes Balears
OAI Identifier:papersSocietatEspeleologica:PapersSEB_2023vol006p019
Acceso en línea:http://ibdigital.uib.es/greenstone/sites/oai-site/collect/papersSocietatEspeleologica/index/assoc/PapersSE/B_2023vo/l006p019.dir/PapersSEB_2023vol006p019.pdf
http://ibdigital.uib.es/greenstone/library/collection/papersSocietatEspeleologica/document/PapersSEB_2023vol006p019
Access Level:acceso abierto
Palabra clave:Speleology
Speleology -- Spain -- Balearic Islands -- Periodicals
Descripción
Sumario:[eng] In this work, the topographic survey and characteristics of a cave with a toponym that recalls a profession that has faded in time, that of road laborers, is made known. It is closely linked to the location of a chasm right on the sidewalk of the road to la Mola. The cave develops entirely on bioclastic Pleistocene or, probably Pliocene, eolianites. It was formed by rock distension and can be considered as a chasm in the vadose zone of mechanical origin. It has a depth of 39 m and a total length of 238 m. The topographical survey shows two different sections, a subhorizontal chamber at the beginning that shows corrosion morphologies in the roof, while the rest of the cave presents a clear vertical trend following the fracture that has generated the void. The fall of rock slabs and blocks has formed false floors and it difficult to appreciate the whole morphology of the chasm. The speleothems decoration is well developed and extensive along the cavity. From a paleontological point of view, the terrestrial mollusk endemic to Formentera Xerocrassa formenterensis, has been found for the first time in a karst site. Several locations with bones have also been discovered, two with the long-nosed bat (Myotis myotis) and one with an anatid bird. This osteological material documents for the first time the presence of this bat species on the island of Formentera, as it is found that it bred in Avenc de sa Casilla, given the abundance of remains of juvenile specimens. Nowadays no living population of this species is known in the Pitiüses.