|
Rifting, sedimentary and oceanic basins, and the formation of continental margins result from processes that tend to thin and extend the continental crust.
Normal faults in the upper brittle crust and viscous flow in the ductile lower crust result from of a stress regime in tension, where the principal stress axis σ1 is vertical. The combined action of normal faulting and horizontal flattenning is responsible for thinning and extension of the continental crust.
As seafloor spreading occur, stretching and thinning of the continental margin stops. Thermal subsidence follows so that the sedimentary pile deposited on the margins consist of pre-, syn- and post-rift packages.
|
|
|
