Grant: Discovery Grants Program - Individual

) When the tectonic plates of Earth's surface collide, or are pulled apart, they create deep depressions (that usually fill with sediments) and/or high mountains. This program is about imaging (by advanced echo sounding) and interpreting plate tectonic processes as they occur, or shortly afterwards, in two contrasted areas. ) The first is the continental edge of Atlantic Canada, which formed by extension and seafloor spreading over 100 million years ago (not long, geologically). This edge preserves a geological record of the events, and hosts significant hydrocarbons. The Newfoundland margin and its Iberian conjugate form a well-studied pair with unusually wide (>100 km) continent-ocean transitions. Recent drilling of the Newfoundland margin found exhumed mantle material, matching similar rocks discovered on the conjugate. Earlier ideas of asymmetrical extension need to be revised! Processing and interpretation of additional seismic data will enable us to delineate the sedimentary basins and transition zones more clearly, and to reconstruct how the margin formed. The second area is the presently-active Cyprus arc in the eastern Mediterranean, which is in transition from subduction to continental collision. Our recent work has documented changing patterns of basin sedimentation and deformation as the convergence direction rotated 45 degrees in the last 15 million years. Now, the intention is to acquire, process and interpret 4000 km of seismic reflection data, at the junction of the Cyprus and Hellenic arcs. Arc junctions are very dynamic plate corners, often the sites of extreme surface relief (e.g., the 5-km deep Rhodes Basin), but poorly understood. These data will provide new insights into the history of this particular corner and, by generalization, into one of the least well-understood aspects of plate interactions. ) The mechanics of these processes underpin attempts to reduce the natural hazards they pose, and to exploit the resources they may contain. So this research will aid geologists interested in fundamental plate processes, those involved in coping with geological hazards, and those searching for hydrocarbon energy resources.