Talk:Central Atlantic magmatic province
|WikiProject Volcanoes||(Rated B-class, Mid-importance)|
Before 200Ma, a spreading ridge running east-west through the length of the ancient Tethys ocean gradually opened up that seaway. About 200Ma, the western end of that Mid-Ocean Ridge (MOR) reached, and ran under, the supercontinent of Pangea, between Africa (to the south) and North America (to the north), as indicated in the following figures:
Now, about 50Ma, the west coast of North America obducted over another MOR (the east Pacific rise). The spreading ridge underneath the continental crust caused crustal thinning, and minor rifting, generating the Basin and Range province, as well as the Yellowstone hotspot and Columbia River Basalt Group. Thus, the CAMP resembles those continental rift zones, except running perpendicular to the coast (instead of parallel to), and on a larger scale, which successfully rifted Africa from North America. Perhaps rifting is facilitated, by perpendicular incidence, of the spreading zone??
More speculatively, about 95Ma, the Tethys MOR may have been subducted under Eurasia, pulling India, then Africa, northwards towards Eurasia. About that time, northern Africa was flooded, leading to the extinction of large northern African dinosaurs & reptiles, like Spinosaurus, Carcharodontosaurus, Paralititan, Sarcosuchus (according to the BBC documentary Planet Dinosaur). Perhaps a change, from compressive force coming southwards from a MOR into northern African continental crust, before 95Ma; to an extensional force pulling northwards to a Subduction Zone (SZ) before Eurasia; caused the northern African crust to stop thickening, and start thinning, depressing the surface below Tethys-sea level?? 18.104.22.168 (talk) 12:45, 17 October 2012 (UTC)