Aerial view of the quarry of Es Racó de Sa Pedrera.
The quarry of Es Racó de sa Pedrera is a good tectonic, eustatic or antropical processes</span></p></div>">outcrop for observing a deposit of sandstones originating from fossil dunes, a stone known in the Balearics by the name of “marès.” These are calcium sandstones with light tones that vary from yellowish-white, reddish-yellow, pink and grey to light brown. The carbonated components can include abundant remains of organisms (algae, gastropods, echinoderms, etc.) Observing the different cross-sections of marès it is possible to identify a certain cross-lamination, very characteristic in these types of deposits, which provides clues about the agent responsible for their formation.
The wind dynamic accumulated grains of sand against the cliff at a moment when the sea level was lower than at present. It is believed that this took place during the Lower Pleistocene (between 2.6 and 1.8 Ma). As the wind makes directional changes, the grains of sand gradually accumulate and create layers of sand that deposit according to the wind direction.
Cross-stratification is formed as a result of grains of sand accumulating on the sliding face. Changes in wind direction complicate this cross-lamination.
Representative diagram of the formation of cross-lamination. Modified from Tarbuck E.J. & Lutgenes F.K., 2005.
Because marès is a very good stone for working and modelling, it has been a very important construction material in the tradition of these islands. It was already being used in Punic and Phoenician times. It is for this reason that a large part of the deposits of marès that existed in Eivissa have been exploited and are now modelled by the hand of man.
Detail of the quarry showing the different phases of extraction of the blocks of marès.
Today, above the deposit of fossil dunes of the quarry, there are a series of modern dunes rising up the slopes. They are formed of sands of light brown or whitish colour partially colonised by vegetation, which assists their stabilisation.
View of the modern rising dunes located above the marès quarry of Es Racó de sa Pedrera.
