Igneous Rock 1
when lava or magma crystallizes and cools
What is the molten material that flows on top of earth's surface?
lava
What is sediment?
Pieces of preexisting rock/small fragments of rock
What is required for metamorphic rocks to form?
high heat and pressure
What is the difference between weathering and erosion?
Weathering - breaking rocks into smaller pieces
Erosion - rock fragments getting carried from one place to another/movement
How do vesicles form?
gas bubbles get trapped in the magma and leave little holes
- ex: pumice
Leads to porosity - the percentage of open spaces between grains in a rock
What is the name of the special microscope geologists use to view thin sections of igneous rocks?
petrographic microscope
What are the two types of weathering?
Chemical weathering - the minerals in a rock are dissolved or otherwise chemically changed.
Physical weathering - the minerals remain chemically unchanged. Rock fragments break off of the solid rock along fractures or grain boundaries.
How are rocks classified as igneous, sedimentary, or metamorphic?
By how they form/method of formation
What type of rock would you likely find fossils?
sedimentary
Magma is classified as basaltic, andesitic, or rhyolitic based on the amount of ______________ it contains
**DAILY DOUBLE**
silica
What is partial melting?
The process whereby some minerals melt at relatively low temperatures while other minerals remain solid
What is lithification?
the physical and chemical processes that transform sediments into sedimentary rocks.
As more sediment is deposited in an area, the bottom layers are subjected to increasing pressure and temperature and they get compacted and cemented to eventually form sedimentary rock
What is the difference between foliated and nonfoliated metamorphic rock?
Foliated - Metamorphic rock whose minerals are squeezed under high pressure and arranged in wavy layers and bands
Nonfoliated - composed mainly of minerals that form with blocky crystal shapes
What are the 4 main agents of erosion?
wind, moving water, gravity, and glaciers.
____________________ shows the relationship between cooling magma and mineral formation
Bowen's Reaction Series
intrusive rocks have larger crystals that can be seen without magnification
extrusive rocks have smaller crystals that require the use of magnification
What are clastic rocks?
Formed from the abundant deposits of loose sediments that accumulate on Earth's surface.
- further classified according to the sizes of their particles.
What type of metamorphism:
Process that affects large areas of Earth’s crust, producing belts classified as low, medium, or high grade, depending on pressure on the rocks, temperature, and depth below the surface
regional metamorphism
What would cause a rock or rock fragment's edges to become rounded?
movement away from source, other rocks bumping into it and chipping away pieces, water moving over the rock and smoothing it out
What is the difference between where intrusive and extrusive igneous rocks form
intrusive forms when magma cools and crystallizes below Earth's surface
extrusive forms when magma cools on earth's surface
What are two ways that igneous rocks are classified?
composition, texture, crystal size, cooling rates
What is bedding and how are the two types differentiated?
bedding is the horizontal layering
Differentiated by the method of transport.
Graded Bedding - bedding in which the particle sizes become progressively finer and lighter toward the top layers
Cross-Bedding - formed as inclined layers of sediment are deposited across a horizontal surface
How are the different grades of metamorphic rocks formed?
different amounts of temperature and pressure
What causes the internal heat of the earth?
**DAILY DOUBLE**
radioactive decay