IODP Expedition 340: Lesser Antilles Volcanism and Landslides

Integrated Ocean Drilling Program (IODP) Site U1398 (CARI-09B, 14°16.70’N, 61°53.34’W, 2935 mbsl) is located west of Martinique. The objective of this site is to characterize the sedimentation processes (related to volcanic activity or not) in the backarc Grenada Basin. It is planned to drill through hemipelagic sediments and turbidites and retrieve a complete sedimentation record down to a depth of ~264 mbsf. The site survey seismic data show that we might penetrate through sedimentary reflectors indicative of the deposition of hemipelagic sediments and turbidites. With the recovered material we hope to be able to distinguish the turbidites related primarily to debris avalanche deposition. One focus is to evaluate whether submarine debris avalanches can generate voluminous turbidites long after their emplacement, and if so how far such turbidites can travel. We also expect to improve the reconstruction of the post collapse eruptive activity of Pitons du Carbet (Boudon et al., 2007). This will provide better constraints on the transition of activity between the Pitons du Carbet and the Montagne Pelée volcanoes. Finally, we also expect to sample turbidites with volcanic material coming from Dominica (e.g. Roseau tuff).