Watching a film set in Cape Town, South Africa, today, I wondered about the geology of Table Mountain, which looms above the city. As is often the case, the natural history of that famous massif is complex.
About 500 million years ago, during the Cambrian Period, a rift valley developed in the southern portion of a continental plate that included today's Continents of South America, Antarctica and Africa. Initially flooded by a shallow sea, the rift accumulated sediments over the next 100 million years. Throughout the late Paleozoic and early Mesozoic Eras, this region was folded, lifted and eroded by tectonic forces as Earth's Continents merged into Pangea and then rifted apart.
Among the sedimentary rocks that formed within the ancient rift valley was a thick layer of hard quartzite sandstone; resistant to erosion, this Table Mountain Sandstone now outcrops as the steep cliffs of Table Mountain and the Cape Fold Ranges of western South Africa. Of note, the western end of this sandstone formation is now found in Argentina, separated from its South African segment as the Atlantic Ocean opened, some 150 million years ago.
About 500 million years ago, during the Cambrian Period, a rift valley developed in the southern portion of a continental plate that included today's Continents of South America, Antarctica and Africa. Initially flooded by a shallow sea, the rift accumulated sediments over the next 100 million years. Throughout the late Paleozoic and early Mesozoic Eras, this region was folded, lifted and eroded by tectonic forces as Earth's Continents merged into Pangea and then rifted apart.
Among the sedimentary rocks that formed within the ancient rift valley was a thick layer of hard quartzite sandstone; resistant to erosion, this Table Mountain Sandstone now outcrops as the steep cliffs of Table Mountain and the Cape Fold Ranges of western South Africa. Of note, the western end of this sandstone formation is now found in Argentina, separated from its South African segment as the Atlantic Ocean opened, some 150 million years ago.
