Volcanoes Flashcards
What are the types of igneous intrusions?
Dike
Sill
Laccolith
Batholith
What is a dike?
Tabular, discordant pluton
What is a sill?
Tabular, concordant pluton
What is a laccolith?
Lens shaped mass
Arches overlying strata upwards
What is a batholith?
Largest intrusive body
Cores of mountains
What are the general features of volcanoes?
Summit opening, vent, fumarole
What is a shield volcano?
Broad, slightly dome-shaped
Cover large areas
Mild eruptions of large volumes of mafic lava
What is a composite cone (stratovolcano) volcano?
Large, classic shape
Interbedded lava flows & pyroclastic debris
Most violent
What is a cinder cone volcano?
Built from ejected lava fragments
Steep slope angle
Small size
Occur in groups
What is nuee ardente?
Pyroclastic flow
Hot gases infused with ash & debris
What is lahar?
Volcanic mudflow
Mixture of volcanic debris & water
What is pyroclastic flow?
Felsic & intermediate magmas
Consists of ash, pumice, & debris
Material ejected at high volumes
What is a caldera?
Summit steep-walled depression
Produced by collapse
What is a fissure eruption?
Mafic lava extruded from fractures called fissures
What is a lava dome?
Bulbous mass of congealed lava
Associated with explosive eruptions of gas-rich magma
