The British Tertiary Volcanic Province (BTVP), synonymous with the term British Tertiary Igneous Province (BTIP), is a large igneous province formed during a time of intense volcanic activity 52–63 million years ago in Britain in the Paleocene and early Eocene epochs of the Paleogene period. During the breakup of the supercontinent Pangea, as the North American Plate and Eurasian Plate rifted apart to form the North Atlantic Ocean, Britain sat above a mantle plume (hotspot). As the earth's crust was stretched above the mantle hotspot under stress from plate rifting, fissures opened up along a line from Ireland to the Hebrides and plutonic complexes were formed. Hot magma over 1000 °C surfaced as multiple, successive and extensive lava flows covered over the original landscape, burning forests, filling river valleys, burying hills, to eventually form a lava plateau named the Thulean Plateau, which contains various volcanic landforms such as lava fields and volcanoes.