Author(s)

D. Broc, A.M.Leclerc & P. Jean-Baptiste

Abstract

Coral reefs and carbonate platforms are time evolutive structures, built on top of a basaltic substrate. Many facts suggest that groundwater flow occurs in the carbonate and influences the geology and the diagenesis of the system. We present here a preliminary study of the hydraulic circulations in atoll islands. If the lagoon is open (communication with the ocean), its water level, temperature and salinity will be the same as in the ocean. Thermo-convective circulations take place, from the ocean towards the lagoon, due to vertical thermal gradient in the ocean. If the lagoon is closed (no communication with the ocean), its water level and salinity will change, depending on the evaporation-precipitation balance. These changes will affect the groundwater circulations. 1 Introduction In an atoll, the carbonate platform results fro

Keywords