Download rifted margin

The Atlantic: “Passive” Ocean Basin
The eastern North American continental margin is not a plate boundary.
The continent/ocean boundary was created when Pangea rifted apart, creating a
transition from continental to oceanic crust through extensional thinning and
magmatic emplacement.
This type of continental margin has historically been referred to as a “passive”
continental margin. The newer and more approapriately descriptive term is rifted
margin. The western African continental margin is also a rifted margin.
There are many things to be noted about rifted continental margins and the
Atlantic in particular, but we’ll emphasize just two:
The names of bathymetric features
• Everyone must know these terms: shelf, rise, abyssal plain, mid-ocean ridge
Rifted-margin sediments can be very thick, > 15 km
• These sediments host much of the worlds hydrocarbon reserves
• These sediments may play a very important role in global elemental cycling
via (1) the retention and release of CH4 within methane hydrate deposits and
(2) submarine groundwater discharge beneath the shelf and perhaps slope
North Atlantic
North Atlantic
Bathymetric Features
North Atlantic
EDGE 801
Baltimore Canyon Trough: EDGE Line 801
Google Earth of Cape Romain Seep