Earth Science Test Flashcards
What are the two types of Igneous Rocks?
Extrusive (volcanic)
Intrusive (Plutonic)
Rocks that form on Earth’s surface
Intrusive Igneous Rocks
Rocks that have small crystals (fine grained)
Intrusive Igneous Rocks
Rocks that cool quickly
Intrusive Igneous Rocks
Rocks that cool slowly
Extrusive Igneous Rocks
Rocks that form below Earth’s surface
Extrusive Igneous Rocks
Rocks with large crystals (coarse grained)
Extrusive Igneous Rocks
Crystals that take a long time to cool
Large Crystals
Crystals that take a short time to cool
Small Crystals
70% silica - thick and viscous
Rhyolitic
Andesitic
60% silica
Rhyolitic
70% silica - thick and viscous
60% silica
Andesitic
Basaltic
50% silica - very hot and fluid
50% silica - very hot and fluid
Basaltic
What are the factors of magma
Temperature
Pressure
Water content
Mineral composition
Temperature
As depth increases:
temperature increases
Pressure
As pressure increases: melting point increases
Water Content
Water content increase:
melting point decreases
Mineral Composition
Oceanic crust (iron and magnesium) has a higher melting point.
Continental crust (silicon and aluminum) has a lower melting point
Bowen’s Reaction Series
Two patterns:
Feldspar Group
Iron-magnesium Group
Feldspar Group
Continuous change
As magma cools, the first feldspars are rich in calcium.
Cooling continues.
Feldspar reacts with magma and it turns to sodium rich.
Iron-Magnesium Group
While magma cools, olivine crystallizes.
Magma continues to cool, olivine changes to pyroxene.
Then pyroxene changes to amphibole, and then to biotite mica.
At the end, quartz veins will form because silica and oxygen are the only substances left to solidify.
How are Igneous rocks formed
Formed from cooled and crystallized molten rock, either at the surface (lava) or deep underground (magma).
How are Sedimentary rocks formed
Deposition and burial then compaction and cementation
What are the two types of Sedimentary Rocks?
Clastic
Chemical
Clastic Sedimentary Rocks
Classified by their particle size, usually deposited in marine environments
Conglomerate
Rounded Particles
Poorly sorted/low porosity
Breccia
Angular particles
Poorly sorted
Sandstone
High porosity (open space)
Well sorted
Siltstone
Silt sized grains, could have fossils
No distinct layers
Low porosity
Well Sorted
Shale
Silt and shale sized grains, could have fossils
Breaks along distinct layers
Low porosity
Well sorted
What are the 2 types of chemical sedimentary rocks
Formed from evaporation
Organic sedimentary rock
Formed from evaporation
This occurs when the water is supersaturated with minerals and they begin to precipitate out of the solution. The process continues as the freshwater evaporates.
Calcite
CaCO3
CaCO3
Calcite
Halite
NaCI
NaCI
Halite
Gypsum
CaSO4
CaSO4
Gypsum
Organic sedimentary rocks
Formed from once living things
EX (Limestone and Coal)
Sorting
When limestone is separated by size or shape
How is Graded Bedding
A change in sediment size from the bottom layer to the top. Generally large sediment on the bottom and small sediment on top.
How is Cross-bedding
Formed in an environments where sediment is deposited in a flowing medium water source
How are Ripple Marks formed
Formed from moving water or wave action
Layering
When sediment is deposited usually in horizontal layers
Fossils
Remains of evidence of a once living plant or animal usually found in shale or siltstone
How are Metamorphic rocks formed
High pressure and temperature combine to alter texture, mineralogy, or chemical composition of a rock without melting it
Where does the heat that forms Metamorphic rocks come from
Earth’s core
Nearby Igneous intrusions
Where does the pressure that forms Metamorphic rocks come from
Vertical rocks from overlying rocks
Compressive pressure from mountain building (orogeny)
Contact Metamorphism
When molten rock (igneous intrusions) comes in contact with solid rock
Hydrothermal Metamorphism
When very hot water reacts with rocks and alters its chemistry and mineralogy
Shale is the parent rock of what
Slate
Granite is the parent rock of what
Gneiss
Sandstone is the parent rock of what
Quartzite
Limestone is the parent rock of what
Marble
Shale is the parent rock of what
Schist
