Site U1398

Integrated Ocean Drilling Program (IODP) Site U1398 (proposed Site CARI-09B; 14°16.70′N, 61°53.34′W; 2935 meters below sea level [mbsl]) is located west of Martinique (Fig. F1). The objective for this site was to characterize the sedimentation processes in the backarc Grenada Basin. We planned to drill through hemipelagic sediment and turbidites and retrieve a complete sedimentation record to ~264 meters below seafloor (mbsf). Site survey data showed that we could penetrate sedimentary reflectors indicative of the deposition of hemipelagic sediment and turbidites. With the recovered material we hope to identify 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 postcollapse 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 Montagne Pelée Volcanoes. Finally, we expect to sample turbidites with volcanic material coming from Dominica (e.g., Roseau tuff).