Marès Quarries on the Majorcan Coast (Spain) as Geological Heritage Sites

Abstract

Mares is a soft rock, generally pale-coloured rock, composed mainly of bioclastic calcareous sandstone which ranges in age from the Late Miocene to the Quaternary, although it dates predominantly from the Pleistocene. This rock was traditionally the main material for construction on the island, with the Palma Cathedral being a classic example. There are numerous mares quarries on the eastern and southern coast of Majorca, some of which are very well exposed in the cliffs. The stone is quarried in large blocks which are later divided into smaller ones. This quarrying process creates deep, vertical quarry walls orientated, both parallel and perpendicular to the coast, which gives an excellent exposure of the rock and clear views of its internal structure. In 2006, the first inventory of geosites on the Balearic Islands was carried out with the aim of defining the geological and hydrogeological heritage in the region. Of the 35 geosites inventoried and catalogued on the island of Majorca, two of them are mares quarries: Estret des Temps on the Santanyi coast and Es Carnatge on the coast of Palma. Both are representative of Pleistocene aeolianites, with excellent exposure of the sets of cross-bedding, while the Estret des Temps quarry also contains noteworthy exposures of hoof prints of Myotragus balearicus, a small endemic goat which became extinct with the arrival of the first human inhabitants of the island, around 7,000 BC. In this study, we propose the inclusion of a new site in the geosites inventory, the Roman quarry of Es Molar de Cala Pi in Llucmajor, where an exceptional sequence of Late-Miocene beaches facies can be observed, including a coquina with large-scale and high-angle cross-bedding and anemone tubes at the base of the quarry. The sequence is crowned by a system of Pleistocene palaeodunes. Such exposure conditions and facies sedimentological variety, coupled with the representativeness of the record, make this quarry a unique site for the study of the Neogene and Quaternary on Majorca