Kaapvaal Craton (02:46)
Hear how plate tectonics lead to diamond formation. Two floating crust fragments collided 2.9 billion years ago to form the African Continent, remnants of which are found in Kimberley, South Africa.
Big Hole Mine (03:00)
Geologists use diamonds to try to date the first African continent. Following their discovery in 1867, prospectors dug a 200 meter hole that revealed a volcanic pipe. Millions of years ago, kimberlite lava brought diamonds to the surface.
Geological History Markers (03:47)
Big Hole diamonds were transported to the surface in kimberlite volcanic rock “hosts.” Carbon-14 dating only applies to 50,000 year old specimens; geologists use garnet mineral inclusions to determine the diamonds are 2.9 billion years old.
Vredefort Explosion (03:35)
Two billion years ago, a meteorite jolted the Kimberley region of the first African continent, revealed in unusual granite composition. The impact generated a central uplift.
Earth Crust Cross Section (03:46)
The Vredefort meteorite blasted a crater 300 km wide and 30 km deep that gives scientists unique subsoil access. At the center, mantle rocks may date back 3.6 billion years. Craters don't normally last on Earth due to dynamic processes.
Fish River Canyon (03:20)
When Gondwana formed, the African and American continents collided and created mountains. Erosion flattened them and an inland sea deposited sediment, forming successive strata layers that Namibia’s river later cut through.
Gondwana Evidence (03:07)
Fish River Canyon contains evidence of plate collision during the super continent's formation. Geologists look for 700 million year old igneous rock in Oman.
Oman's Origins (03:10)
Geologists collect igneous rock samples that formed 700 million years ago. Crystals containing iron were oriented to Earth's magnetic field and "memorized" the rock's location. Lab analysis shows they were part of Gondwana at 30 degrees south.
Cape Fold Mountains (03:38)
South Africa's Table Mountain was part of a larger chain that formed during Gondwana as South America and Antarctica collided with Africa.
Cape Town Geology (03:41)
Magma rose to the surface and cooled, forming granite. As the Adamastor Ocean Plate subducted beneath the African Plate, it intruded into darker rock called the Malmesbury Group. This continental collision formed Gondwana.
Namibia's Fossilized Trees (03:34)
Gondwana formation was complete 500 million years ago. As it drifted, the super continent moved into the South Pole. The Demaraland savanna holds traces of the glaciation period; hear how wood becomes petrified.
Gondwana Climate Changes (02:13)
Petrified trees in Namibia prove that the super continent was at the South Pole 300 million years ago. It gradually moved north to warmer climates.
Madagascar's Origins (03:24)
Gondwana dispersed into the modern continents. Madagascar separated from Africa 165 million years ago and remained attached to India. Eighty-eight million years ago it moved to its current position and evolved a unique ecosystem.
Madagascar's Ecology (02:21)
Separated from Africa and Asia for millions of years, the island developed endemic plant and animal species. Lemur origins remain a mystery; hear hypotheses of how they arrived on the island.
Lemur "Raft" Theory (03:42)
Most scientists believe the primates traveled from Africa to Madagascar on floating vegetation. Africa continues moving north and the Rift Valley separates a new subcontinent.
Credits: The Origins of Africa—Voyage of the Continents, Series 2 (00:58)
Credits: The Origins of Africa—Voyage of the Continents, Series 2
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