In October 2004, seismic reflection data were collected from the Cap de Creus shelf and canyon (Interactive Map) to characterize the geologic framework and sedimentary environments of the continental shelf, slope and canyons of the southwest portion of the Gulf of Lions. This area is the focus of active research as part of the EuroSTRATAFORM project funded by the Office of Naval Research.

A unifying concept of the EuroSTRATAFORM Program is that sediment accumulates on the shelf and slope in predictable patterns that are controlled by water depth, sediment sources, and the principal modes of transport and deposition. A principal goal is to improve our understanding of how strata form and how they combine to form characteristic stratigraphic sequences, such as drapes, aprons, wedges, sigmoids, and other well recognized geometrical patterns. The geometry of stratification, as represented by acoustic reflectors in the upper 50 m of the shoreface, continental shelf and continental slope is critical to interpreting the evolution of sedimentary strata and sequences and shedding insight on the mechanisms of sediment transport and deposition. Interpreting the signatures of various processes in near-surface deposits provides a critical link between knowledge gained from measuring physical processes that are dominant over time spans from the duration of a single event to several years, and those inferred from interpretations of entire stratigraphic sequences on continental margins that may represent 102 to 104 years of deposition. The objective of our research was to identify the character and origin of sediment bodies on the continental shelves surrounding and within the Cap de Creus Canyon. Overall, our study emphasizes the internal architecture and evolutionary growth of geologically young shelf and nearshore sediment bodies.

Efforts to characterize the sedimentary environments of the Cap de Creus shelf and canyon were complemented by oceanographic and sediment transport investigations using moored instrumentation to acquire time-series information on currents and fluxes of water masses and sediment moving across the shelf. These data and results are reported at the EuroSTRATAFORM web site: http://www.soc.soton.ac.uk/CHD/EUROSTRATAFORM/index.html.

Key sedimentary features imaged in this study and examined as part of the Cap de Creus project include highstand deposits. Highstand deposits are important indicators of latest sea level history (e.g. Torres et al., 1995; Marsset and Bellec, 2002) and recorders of impacts from human intervention in drainage basins. They are also areas of potential hazards. The rapid accumulation style that characterizes many highstand deltas, typically areas of high population density, can lead to instability (Correggiari et al., 2001). Despite the relevance of information about highstand sediment bodies, the details of how these large sediment bodies form, shift, and grow are not well documented.

Our study was carried out to provide a critical link to colleagues conducting studies of short-term physical processes and those developing models of continental shelf deposition.