Geology of St Lucia

The geology of the island has been subdivided into 1) Eroded basaltic and andesitic centers, which are further subdivided into Northern Series (18.30.9 to 4.660.23 Ma) and Southern Series (10.120.50 to 5.210.15 Ma), 2) Dissected andesite centers (10.400.52 to 2.020.08 Ma), 3) Soufriere Volcanic Center, which has been further subdivided into a) Early Effusive activity (6.50.6 to 5.61 0.25 Ma), b) Andesitic stratovolcanoes –Mt. Gimie (3.30.16 to 0.90.8 Ma), c) Early dome forming activity –Petite Piton (0.260.04 Ma) and Gros Piton (0.290.1 to 0.230.1 Ma), d) Dacitic pyoclastic flow deposits-Choiseul Tuff (39,0501500 to <32,840 yrs B.P.), Belfond pyroclastic flow (34,2001670? to 20,0001,120 yrs. B.P.), e) Late stage lava domes and explosion craters- Morne Bonin dome, Belfond dome.