Earth Science, Tarbuck Chapter 3 Flashcards
What does a magma body do when fully formed
rises up the crust due to lower density.
Magma that is on the surface
Lava
What is lithification
Conversion of Sediment into rock
What type of Igneous rock is formed below surface
Plutonic Igneous Rocks
What type of Igneous rock is formed above surface
Extrusive Igneous rock
What causes larger crystals to form in igneous rock
Slower Cooling
What happens when magma is cooled quickly
Smaller, more abundant Crystals
What happens when magma is “instantly” cooled
Glass forms, as ions are randomly distributed
define dark silicate minerals
Rich in iron/magnesium, lower in silica
Common dark silicate minerals
Olivine, pyroxene, amphibole, biotite
1define light silicate minerals
Greater amounts of Potassium, Sodium, and Calcium, richer in silica
Common light silicate minerals
Quartz, Muscovite, Feldspars
What percent of Igneous rocks are feldspars
40%
All groups of Igneous Rocks
Granitic, Andesitic, Basaltic, and Ultramafic
What are basaltic rocks also called
Mafic Rocks
What are Granitic Rocks also called
Felsic rocks
What are Andesitic Rocks also called
Intermediate rocks
Coarse and Fine grained Granitic Rocks
Coarse: Granite, Fine: Rhyolite
Coarse and Fine grained Andesitic Rocks
Coarse: Diorite, Fine: Andesite
Coarse and fine grained basaltic rock
Coarse:Gabbro, Fine: basalt
Coarse and Fine-grained Ultramafic Rocks
Coarse: Peridotite, Fine: Komatiite
Porphyritic Rocks
magma undergoes 2 stages of cooling, one fast, one slow, allowing for different crystal size
What is a phenocryst
Large Crystals in Porphyritic Rock
What is Groundmass
The Matrix of Smaller crystals in a Porphyritic Rock
What are Vesicles
Spherical Openings in Extrusive igneous rock representing gas bubbles
Where do Rocks with vesicular texture mostly form
Upper zone of Lava flow, where Cooling is quick enough to preserve openings created by expanding gas bubbles
What causes igneous rock to have “glassy texture”
Rapid cooling as molton rock is ejected into the atmosphere causes the ions to have no time to arrange themselves into crystals
What are Pyroclastic Rocks
Igneous rocks that are made up of fragments of volcanic rock, almost like a sedimentary rock
Difference between Rhyolite and Granite
Granite is intrusive(Coarse Grained), Rhyolite is Extrusive(Fine grained)
Coarse Grained Grainitc
Granite
Coarse Grained Andesitic
Diorite
Coarse Grained Basaltic
Gabbro
Coarse Grained Ultramafic
Peridotite
Fine grained Granitic
rhyolite
Fine grained Andesitic
Andesite
Fine grained Basaltic
Basalt
Fine grained Ultramafic
Komatiite
Glassy Granitic
Obsidion
Vesicular Granitic
Pumice
Vesicular Basaltic
Scoria
Why do Igneous rocks have a wide variety of composition
Different minerals crystalize at different times
List bowen’s reaction sequence in order
Olivine, Pyroxene, Plagioclase Feldspar, Amphibole, Biotite, Muscovite, Potassium Feldspar, Quartz
What do minerals do to surrounding elements as they crystallize
Selectively removes certain elements from the magma mix
Crystallization of Olivine and Pyroxene removes what and how does that affect the rest of the magma mixture
iron and Magnesium, causing the rest of the mix to be more felsic
What is one way magma removes the already crystallized minerals from the mixture.
Crystal Settling
Define Crystal Settling
When Crystals that form early on in a magma chamber are denser than the surrounding magma, causing the crystals to sink to the bottom, leaving the rest of the magma more felsic, as iron and magnesium is pulled out.
Define Magmatic Differentiation
When Crystal settling changes the chemical composition of the magma, as the mafic material sinks to the bottom of a magma chamber
What is Detritus
Sediment Originating from weathered rocks
What are detrital sedimentary rocks
Sedimentary rocks formed from weathered pieces of other rock
Detrital Sedimentary rocks are classified through
particle size
Detrital Sedimentary rocks are most commonly formed of
Clay minerals and Quartz
2-256 millimeters
Gravel
1/16 - 2 millimeters detritus
Sand
1/256 - 1/16 millimeters detrital sediment
Silt
<1/256
Clay
Define Conglomerate
Sedimentary rock consisting of lots of rounded gravel-size particles