CORE TO INDUSTRIAL ECOSYSTEM INTERACTION IN AFRICA OVER THE PAST 200 MILLION YEARS

No refrigerating slabs have penetrated the mantle under Africa for the past 200 My. Material close to the CMB under Africa may be the hottest part of the Earth's mantle. Heat has been extracted from that hot volume in five giant plumes: CAMP @ 201 Ma, Karroo @ 183 Ma, Tristan @ 133 Ma, Deccan @ 65 Ma, Afar @ 31. Eruptions of all but CAMP were followed by the formation of new plate boundaries which, by 126 Ma,isolated Afro-Arabia among spreading-centers. Two plumes, Karroo and Afar, temporarily (183-133 Ma and 31-5 Ma) arrested their overlying plate's motion. The two arrest episodes were characterized by: Basin and swell formation, rift-formation and intra-plate magmatism. All are attributable to the setting-up, at arrest, of a new pattern of shallow-mantle convection. Erosion of the young swells led to the deposition of potential source and reservoir rocks in rifts and at young rifted margins. Source-rocks in the 183-133 Ma rifts and on related continental margins are now generating oil and gas because of burial under sediments eroded from the set of swells related to the Afar plume . Oil and gas accumulations are being developed e.g.in the Niger delta and off Angola in those rocks. Rifts in E.Africa which formed in response to the eruption of the Afar plume provided the environment in which hominids evolved and in which their fossil remains are best preserved and exposed. Climatic variation over the past 34 My in Africa has been dominantly a response to the formation of polar ice-sheets and to fluctuations in their contained ice-volumes. Antarctic ice-sheet influence has made S. and E. Africa particulaly dry since 34 Ma.The greater elevation of that area (known as "High Africa") is a reflection of less erosion rather than greater elevation. In Africa it is proving possible to glimpse ways in which diverse parts of the Earth System: core,lower-mantle, upper mantle,lithosphere,hydrosphere,atmosphere and biosphere (including human and industrial ecosystems) have interacted since 200 My.