FRG25 EE – RESPECT-Ethic- the geological reserve of La Désirade

Sarah Sellier introduced the reserve by explaining its scientific and heritage importance. She reminded us that La Désirade is one of the oldest rock outcrops in the Lesser Antilles, dating from the Upper Cretaceous, more than 145 million years ago. Emphasis was placed on the different types of rocks present (serpentinites, basalts, limestones) and their geological significance. Teachers were guided in observing the reliefs and characteristic rock formations of the island.

Observation of limestone cliffs: formed by the accumulation of ancient marine deposits. Identification of basalts and serpentinites: evidence of ancient tectonic and volcanic activity. Impact of erosion: role of wind and sea in modifying the landscape. Presence of faults and fractures: consequences of regional tectonic movements.

This reading of the landscape was done through drawing. A practical session allowed teachers to experiment with the use of topographic maps and compasses. Sarah Sellier explained how to interpret contour lines, identify natural landmarks, and use the sun and stars for orientation.

During the visit, several endemic species were observed.

Fauna: Delicatissima iguana, seabirds (boobies, tropicbirds) Flora: Vegetation adapted to arid conditions, xerophytic plants, importance of coastal mangrove formations. Discovery of the endemic cactus "Tête à l’Anglais": This cactus, unique to La Désirade, plays an essential role in the local ecosystem by providing food and shelter to certain species. Its adaptation to extreme conditions and its ecological importance were highlighted by the guide.

This visit provided teachers with an immersive and enriching experience. La Désirade serves as an ideal natural laboratory for learning Earth and environmental sciences. The reserve's involvement in educational projects could be strengthened through collaborations with schools.