Volcanic plateau

The resulting sheet lava flows may be extruded from linear fissures or rifts or gigantic volcanic eruptions through multiple vents characteristic of the prehistoric era which produced giant flood basalts.

[1] Perhaps the most extensive of all the subaerial basaltic plateaus existed during the Paleogene[2] and possibly extended over 1,800,000 km2 (690,000 sq mi) of the northern Atlantic Ocean region.

This region, known as the Thulean Plateau, is generally believed to have been broken up by the foundering of the Earth's crust to form the present ocean basin.

They are underlain by pyroclastic rocks: agglomerates, tephra, volcanic ashes cemented into tuffs, mafic or felsic.

Examples include the Shirasu-Daichi, which makes up almost all of southern Kyūshū, Japan,[3] and the North Island Volcanic Plateau in New Zealand.