ERS103H5 Lecture Notes - Lecture 11: Basalt, Lapilli, Tephra
Document Summary
Volcanic eruptions the ground: lava flows: molten rock that moves over, valocanic gases: expelled vapor and aerosols (cause more damage than lava, pyroclastic debris: fragments blown out of a volcano. *columnar jointing is most common in basalts but is seen in other igneous rocks: deccan flood basalts: large igneous province in india that erupted between 67 63 ma, at the cretaceuos paleogene boundary; . 2km thick, with an areal coverage of 500,000 km2 (originally 1. 5 million km2) and a volume of 512,000 km3 all deposited in less than 30 thousand years, pillow basalts: are blobs of basalt cooled rapidly by quenching in water. Basaltic eruptions form lava fountains that spew gases and eject clots and drops of: lapilli: pea sized fragments, pele"s tears: frozen droplets, pele"s hair: thin glass strands, blocks: large fragments, bombs: streamlined by falling through air while molten.
