Insights from Scientific Drilling on Rifted Continental Margins

• Main Authors: Louden, Keith, Lau, Helen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Association of Canada 2001
• Subjects: North Atlantic
• Online Access: https://journals.lib.unb.ca/index.php/GC/article/view/4101

Sampling of sedimentary and crustal formations across rifted continental margins has long been a priority of DSDP, ODP, and other scientific ocean drilling. Recent results of drilling and related geophysical surveys across several margin segments in the North Atlantic have revealed that continents break apart in two fundamentally different ways. Volcanic margins form when rapid mantle up-welling produces a large amount of melt just prior to and during rifting. On non-volcanic margins, slow rates of rifting the continental crust expose regions of serpentinized mantle with little evidence of melting. Sampling, however, has thus far been restricted to regions of thin sediment cover, which has limited our ability to study the full range of rifted margin evolution. The next phase of scientific drilling will have enhanced capabilities that will allow drilling of both shallow- and deep-water basins, including those with thick sediments with hydrocarbon potential, such as the outer Grand Banks and Scotian margins. To make this a reality, it will be essential to combine both industry and academic interests and work to ensure continued Canadian participation. Résumé L'échantillonnage des formations sédimentaires et crustales à travers les marges continentales divergentes, a longtemps été une priorité pour le DSDP, l'ODP et d'autres projets scientifiques de forages océaniques. De récents résultats de forages et de levés géophysiques concomitants à travers plusieurs segments de marges en Amérique du Nord ont montré que les continents se fragmentent de deux façons fondamentalement différentes. Des marges volcaniques se forment lorsque des remontées mantelliques entraînent l'accumulation de forts volumes de roches fondues juste avant et durant la distension crustale. Sur les marges non-volcaniques, de faibles taux de distension crustale dévoilent des régions de nature mantellique serpentinisées montrant peu d'indices de fusion. Mais, jusqu'à présent, l'échantillonnage a été limité aux régions au couvert sédimentaire mince, ce ...