Tanzanian Craton

Chesley J. T., Rudnick R. L., and Lee C.-T. (1999) Re—Os systematics of mantle xenohths from the East African rift age, structure, and history of the Tanzanian craton. Geochim. Cosmochim. Acta 63, 1203—1217. 

Figure 12 Normative garnet Iherzolite mineral abundances (wt.%) versus rock Mg for low-temperature cratonic mantle. Data are open circles, Kaapvaal craton (Boyd and Mertzman, 1987 and references therein) filled diamonds, Tanzanian craton (Lee and Rudnick, 1999) open triangle, Siberian craton (Boyd et al., 1997) cross. Slave craton, northwest Canada (Kopylova and Russell, 2000) filled triangle, northern Canadian craton (Schmidberger and Francis, 1999) and inverted triangle, central Greenland craton (Bernstein et al., 1998).

Chesley, j. T., Rudnick, R. L. Lee, C. T. 1999. Re-Os systematics of mantle xenoliths from the East African Rift age, structure and history of the Tanzanian craton. Geochimica et Cosmochimica Acta, 63, 1203-1217. 

The East African Rift System is an example for a large-scale zone of continental extension where two lithospheric plates slowly spread apart (at about 5 mm/year). The earthquake distribution is broader than at mid-ocean ridges, and the rift actually splits into an eastern and western branch when it encounters the relatively strong and deep-rooted Tanzanian Craton. Earthquakes have normal-faulting mechanisms with strikes parallel to the direction of the East African Rift... 

Figure 18 Normative olivine and opx (garnet Uierzo-Ute norm) versus rock Mg showing low-T cratonic mantle relative to batch melt extraction trends from 3 GPa to 7 GPa (see Figure 6). Open circles are compositions from the Kaapvaal, Siberian, and Slave cratons, and the filled circles are compositions from the Tanzanian, Canadian, and Greenland cratons.

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