HIST 2061 : Doctor Allen Quiz1 1
Document Summary
Volcano erupting vent through which molten rock surfaces. Lava flows molten rock that moves over the ground. Pyroclastic debris fragments blown out of a volcano. Volcanic gases vapor and aerosols that exit a volcano. Can be thin and runny, or thick and sticky. Mafic or basaltic very hot, low silica, low viscosity. Lava tube the insulated, tunnel-like conduit within a flow, through which lava moves. Pahoehoe hawaiian word describing basalt with a glassy, ropy texture. A"a hawaiian word describing basalt that solidifies with a jagged, sharp, angular texture. Columnar jointing solidified flows that contract with vertical fractures that are hexagonal in cross section (create hexagonal columns) Pillow basalt rounded blobs of basalt that cooled underwater. Intermediate or andesitic more viscous, don"t flow as rapidly. Silicic, felsic, or rhyolitic have the highest sio2, most viscous, rarely flows, coolest lava. Form lava domes above the vent, and can be blown up by later eruptions.
