Minerals
What is the basic building block of minerals?
Elements
What causes magma to form in the Earth? (Name one of the three main conditions)
Increase temperature / Decrease pressure / Increase water content
What term describes an intrusion of magma that cuts across existing country rock and is typically tabular in shape?
Dike
What type of eruption involves low viscosity magma and results in gentle lava flows?
Effusive or gentle eruption
Name the three major rock types.
Igneous, Sedimentary, Metamorphic
Name the mineral group that makes up about 95% of Earth’s crust.
Silicates
What type of igneous rock forms when magma cools slowly beneath the Earth’s surface?
Intrusive or plutonic rock
What is the difference between concordant and discordant plutons?
Concordant plutons are parallel to country rock layers; discordant plutons cut across country rock layers.
Name the fast-moving, hot cloud of gas and volcanic material that flows down volcano slopes.
Pyroclastic flow
What term describes the texture of igneous rocks with large crystals formed by slow cooling?
Phaneritic
Which type of chemical bond involves the transfer of electrons between a metal and a non-metal?
Ionic bond
According to Bowen’s Reaction Series, which mineral crystallizes first from magma?
Ferromagnesian minerals
Which famous batholith in Texas is known for its large granite dome and exfoliation features?
Enchanted Rock Batholith
What volcanic explosivity scale measures the size and power of eruptions?
Volcano Explosivity Index (VEI)
What type of igneous rock texture forms from rapid cooling resulting in microscopic crystals?
Aphanitic
What mineral property describes a mineral’s resistance to scratching?
Hardness
What is the main factor that determines the viscosity of magma?
Silica content
What type of volcanic eruption is characterized by violent explosions due to high gas content and viscous magma?
Explosive or cataclysmic eruption
What is the term for a large crater formed when the roof of a magma chamber collapses?
Caldera
What is the main compositional difference between felsic and mafic igneous rocks?
Felsic rocks have higher silica content; mafic rocks have higher iron and magnesium
Name the mineral with a cubic crystal structure commonly used as table salt.
Halite
Name the most abundant rock type found in the oceanic crust.
Basalt
What large plutonic body, often granite, forms the core of many mountain chains and can be over 20 km thick and cover more than 100 square kilometers?
Batholith
Name the volcanic mudflows caused by a mixture of water and volcanic debris.
Lahars
Which igneous rock is characterized by a mixture of felsic and mafic minerals and is commonly found at subduction zones?
Intermediate (e.g., Andesite)