The palaeogeography of the opening South Atlantic

Abstract

Abstract The history of South Atlantic palaeogeography begins with the supercontinent, Pangaea. The assembly of Pangaea began with the middle Palaeozoic collision of north-western Europe with North America on the west and the Siberian platform on the east to form the continent called Laurussia. Shortly thereafter (geologically), Gondwana collided with Laurussia. The final assembly of Pangaea occurred in the Early Triassic with the collision between North and South China that raised the Chinling Range (J. M. Parrish et al. 1986). No sooner had Pangaea come together than it began breaking up. Continental deposits associated with the initial rift valleys in eastern North America are Triassic in age. The Central Atlantic opened first between north-western Africa and south-eastern North America. Because South America and Africa were still one plate, the opening of the Central Atlantic caused relative motion between North and South America; the Gulf of Mexico and eventually the Caribbean formed in the intervening space. The opening of the South Atlantic began in the Early Cretaceous. The final plate separation in the circum-Atlantic region was between North America and north-western Europe. The central focus of this book is the history of connections between Africa and South America, and so the history of the South Atlantic forms the principal focus of this chapter. However, connections between North and South America and Africa and Europe (and thus North America) are also discussed.