[3] Karoo-Ferrar formed just prior to the breakup of Gondwana in the Lower Jurassic epoch, about 183 million years ago;[4] this timing corresponds to the early Toarcian anoxic event and the Pliensbachian-Toarcian extinction.
The long-lasting Chon-Aike Province in Patagonia, the Antarctic Peninsula, and Ellsworth Land was activated c. 190 Ma in an unstable tectonic environment in which both extension and subduction occurred.
The Karoo LIP ended 145 Ma with peripheral eruptions in Patagonia, the Antarctica Peninsula, northern South Africa, Kerala in India, and southeast Australia.
[8] In the Cretaceous, some 15 million years after the last Karoo eruption, renewed magmatism was initiated between Mary Byrd Land in Antarctica and New Zealand from where it spread along Gondwana's southern margin, from eastern Australia to the Antarctic Peninsula.
These continental tholeiites are indicative of a large-scale extensional rift system and associated Middle Jurassic magmatic activity linked to the break-up of Gondwana 25 m.y.