EESA06H3 Chapter Notes - Chapter 3: Ol Doinyo Lengai, Rift, Olduvai Gorge
Divergent plate boundaries are places where tectonic plates are pulling apart and new lithosphere is being created. This module looks at the processes through which continents split to make new plate boundaries, and how earth"s ocean basins are formed. Describe the stages in the creation of a new ocean basin. Use lithospheric age data to predict how continents may have shifted in the past. As continents break apart, new oceans are created. This process can be broken down into three stages: embryonic rift basins, juvenile ocean basins, mature ocean basins. Continental extension often begins where mantle plumes are heating continental crust from beneath. This heat causes the crust to dome upwards and split, often along three linear arms of a triple junction. Each arm is a rift basin where slivers of crust subside along normal faults. Examples include the east african rift, midland valley of scotland, the basin and.