Prolonged magmatic and tectonic development of the Caribbean Igneous Province revealed by a diving submersible survey

Using the diving submersible survey NAUTICA we investigated the central par t of the Caribbean large igneous province (CLIP) to observe and sample inte rnal portions of this proposed oceanic plateau. Most of the samples are gab broic and doleritic rocks; basalts are scarce. Radiometric dating by Ar-40/ Ar-39 incremental heating experiments indicate that the intrusive rocks are Campanian in age (81-75 Ma). In some places these intrusive rocks underlie older Santonian (85-83 Ma) extrusive basaltic rocks, suggesting that the C ampanian rocks represent a sill injection and an underplating episode. Resu lts of the diving program supplemented by information from ODP and DSDP dri lling sites document a 20 m.y. period (94-75 Ma) of igneous activity in the submerged portion of the Caribbean large igneous province (CLIP). In the n orthern part of the Beata Ridge late Campanian and/or post Campanian uplift is documented by prominent Maastrichtian (71-65 Ma) erosion and the establ ishment of a Paleocene-middle Eocene (65-49 Ma) carbonate platform. During and after the uplift an extensional period is indicated by seismic images a nd the subsidence (3 km depth) of the carbonate platform. Paleocene ages (5 5-56 Ma) determined on some volcanic samples are attributed to localised de compression mantle melting that accompanied the extension. We document a pr olonged period of magmatic and tectonic events that do not fit with the cur rent models of short-lived plateau formation during mantle plume initiation but shares many similarities with the constructional histories of other oc eanic large igneous provinces.