Passive continental margins
Passive continental margins formed in the course of the Earth’s history when ‘super’ continents broke up and the new continents drifted apart forming new oceanic crust in between. At the boundaries of the new continents, like the margins of Africa and South America after the break-up of Gondwana, the continental and the oceanic crust are firmly welded and tectonic movements have ceased. Therefore, these areas are called passive margins in contrast to the active margins with their ongoing subduction processes. The passive margin type is prevalent around the whole Atlantic and Arctic and large parts of the Indian ocean, as well as around the Antarctic and Australian continents
But there is one important process, the sedimentation, that generally continues until today. Therefore, most of the passive margins show thick sedimentary layers in the order of several kilometers that may contain important hydrocarbon (oil and gas) deposits. This is the reason why BGR investigates selected passive continental margins using marine geophysical and geological methods and why BGR is engaged in IODP drilling campaigns dedicated to the investigation of the paleo-oceanographic conditions of sedimentation processes.
In recent years, the focus was concentrated on the margins of the South Atlantic. This also includes the investigation of the deep sedimentary rift basins that formed marginal basins like the North Sea..