Volcano Basics
What is a volcano?
A volcano is an opening in Earth's crust through which magma, lava, gases, and ash can escape to the surface.
What type of eruption is characterized by steady flows of lava?
An effusive eruption is characterized by steady flows of lava with low gas content.
What type of rock forms from the cooling of magma or lava?
An igneous rock is formed from the cooling and solidification of magma or lava.
What term describes large crystals visible to the naked eye?
Coarse-grained rocks have large crystals visible to the naked eye, formed by slow cooling.
What does Bowen's Reaction Series describe?
Bowen's Reaction Series describes the order in which different minerals crystallize from cooling magma.
What is molten rock material beneath Earth's surface called?
Magma is molten rock material beneath Earth's surface that contains dissolved gases and crystals.
What is the fast-moving current of hot gas and ash called?
A pyroclastic flow is a fast-moving current of hot gas, ash, and volcanic debris that flows down volcanic slopes.
Name the fine-grained volcanic rock that is the equivalent of granite.
Rhyolite is the fine-grained volcanic rock that is the equivalent of granite.
What is the texture of rocks that contain holes from trapped gas bubbles called?
The texture of rocks that contain holes from trapped gas bubbles is called vesicular.
Name one mineral that crystallizes at high temperatures according to Bowen's Reaction Series.
Olivine is one mineral that crystallizes at high temperatures according to Bowen's Reaction Series.
The vent is the opening through which volcanic material is ejected.
What is volcanic ash?
Volcanic ash consists of fine particles of pulverized rock and glass ejected during explosive eruptions.
What is the difference between intrusive and extrusive igneous rocks?
Intrusive igneous rocks form below Earth's surface from slowly cooling magma, while extrusive igneous rocks form at or above Earth's surface from rapidly cooling lava.
Define coarse-grained igneous rock.
Coarse-grained igneous rock is formed by slow cooling, allowing large crystals to develop.
What is the difference between the discontinuous and continuous series in Bowen's Reaction Series?
The discontinuous series includes minerals that change completely as temperature drops, while the continuous series involves plagioclase feldspar that changes composition gradually.
What is a crater?
A crater is a bowl-shaped depression around a volcanic vent.
Define explosive eruption.
An explosive eruption is a violent eruption caused by high gas pressure, producing ash, pyroclastic flows, and volcanic bombs.
Name a dark-colored, mafic igneous rock.
Basalt is a dark-colored, mafic igneous rock composed mainly of pyroxene and plagioclase feldspar.
What does glassy texture indicate about a rock's cooling rate?
A glassy texture indicates that a rock cooled extremely rapidly, preventing crystal formation.
How does Bowen's Reaction Series help predict rock composition?
Bowen's Reaction Series helps predict rock composition by indicating which minerals are likely to be found together in igneous rocks based on their crystallization temperatures.
Describe the magma chamber.
The magma chamber is an underground reservoir where magma collects before an eruption.
What is the difference between effusive and explosive eruptions?
The difference between effusive and explosive eruptions lies in the gas content and pressure; effusive eruptions are gentle and produce lava flows, while explosive eruptions are violent and expel ash and debris.
What is pumice, and how does it form?
Pumice is a light-colored, vesicular volcanic rock that can float on water, formed from the rapid cooling of lava with gas bubbles.
How does cooling rate affect crystal size in igneous rocks?
The cooling rate affects crystal size; slower cooling produces larger crystals, while rapid cooling results in smaller crystals.
Explain why certain igneous rocks have predictable mineral combinations.
Understanding Bowen's Reaction Series explains why certain igneous rocks have predictable mineral combinations and how cooling rate influences which minerals can form.