The Karoo LIP: The Destroyer of GondwanaAbout 500 million years ago, a huge continent was assembled

The Karoo LIP: The Destroyer of GondwanaAbout 500 million years ago, a huge continent was assembled due to collisions between multiple ancient cratons, or cores of continents. This supercontinent, Gondwana (Gondwanaland) contained what we know today as Africa, South America, The Arabian Peninsula, India, Antarctica, Australia, and New Zealand – give or take that’s something like ½ of the planet’s continental landmass. That large continent held together for nearly 400 million years, and was even joined with a few other large landmasses for a time to create Pangaea.It lasted for about 10% of Earth’s history, and here you’re looking at the leftovers of its killer.183 million years ago, a blob of hot material moved upwards through Earth’s mantle, silently sneaking up on the base of that continent. When it reached shallow depths, it impinged on the crust itself, pushing it upwards into a large dome. Molten rock poured from giant fractures, creating systems of dikes and lava flows that covered the landscape. The welt in the crust was enough to cause the crust to crack, eventually snapping one piece after another away from the continent.There were a few additional helpers – there are a couple of similar mantle plumes that rose up between South America and Africa to break those continents apart, but the Karoo’s damage created far more continental havoc. Two continents (Antarctica and Australia) as well as the Indian Subcontinent and several other slivers of crust (Madagascar) were separated from Gondwana and pushed across the surface by the intrusion of the Karoo Large Igneous Province (LIP). It has different names across different continents, as you see in the final image, but they all formed from the massive plume of hot mantle that rose up beneath Gondwana.Today, the dikes and lava flows of the Karoo province are partially preserved, some of them still trapped under the ices of Antarctica. Where they intruded softer rocks such as shales, the dolerites form resistant layers that are hard to erode, creating koppies like the ones seen in the large shot. Others form cliffs and fill fractures throughout the bedrock of these continents.-JBBimage credits:https://en.wikipedia.org/wiki/Karoo_Supergroup#/media/File:Karoo_Koppies.pnghttps://flic.kr/p/RLe8GHhttp://www.largeigneousprovinces.org/13aprReference:http://karoospace.co.za/dolerite-karoos-fracking-game-changer/ -- source link
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