EESA06H3 Chapter Notes - Chapter 3: Rift, Oceanic Basin, Continental Crust
Document Summary
This process can be broken down into three stages: 2: mature ocean basins, embryonic rift 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 silvers of crust subside along normal faults. East african rift: classic example of an embryonic rift basin, numerous faults trending approx. Volcanoes of the east african rift: the peaked cone with it"s top in the clouds is an active volcano caused oi doinyo. Lengai which is very unusual because it produces carbonate (rather than silicate) Erte ale: curst in the afar triangle is so thin that basaltic magma is erupting in great volumes, because basaltic magma is fairly runny, it creates shield volcanoes. Form broad low-gradient "shields: erte ale is one such shield volcano in the afar triangle.
