The Majorca Site (Baleares, Spain) was initially established under the European ALIANCE Project (FP5, 2002-2005). The site is located at Ses Sitjoles, 8 km southwest of the town of Campos, in the southeastern part of the island of Majorca. It comprises a network of twelve 100-m-deep boreholes (seven of them fully cored) on a one-hectare (100 m square) site. These boreholes intersect the Miocene reefal limestones in the southeast of the island, six km from the Mediterranean coast. In that area low recharge and over-exploitation due to agriculture have led to an intrusion of salt water up to 15 km into the island, and thus to chloride pollution of the groundwater. At Ses Sitjoles the start of the transition from fresh water (1.5 g/l) to salt water (3 g/l) lies at a depth of 60 m. The environment is totally saturated in salt water at a depth of about 75 m. The base of the fresh water corresponds to the highly heterogeneous core of the reef, the intrusion being located in the most homogeneous part, consisting mainly of talus.
The Majorca Site (Campos) is both an observation and an experimental site.
Site for observing:
- a saline intrusion in an insular, semi-arid setting,
- the impact of this intrusion, caused by agricultural over-exploitation.
Site for research and experiment on:
- the heterogeneous structure of reefal formations, at scales ranging from µm (x-ray) to 100 m (depth of investigation);
- the heterogeneous nature of flows in a reefal setting;
- carbonate diagenesis in a saline intrusion setting.