Download Chapter 4 Rocks

Chapter 4 Rocks
Granite contains quartz, orthoclase feldspar, and
biotite.
What is a Rock?
It is a mixture of minerals and organic matter.
Rocks are classified into 3 types by how they are formed.
Igneous-cooling magma or lava
Sedimentary- cemented and compacted fragments
Metamorphic-heat and pressure
What are the processes that make
or destroy rock?
Weathering
Breaking down of rock by wind, water, ice, heat,
animals.
Erosion
Moving rocks and sediment from one location
to another by wind, water, ice and gravity
Deposition
When moving sediment comes to rest.
Uplift
Upward movement of crust caused by plate
movement.
Melting/Cooling of Rock
Occurs near volcanically active areas or deep in
Earth’s mantle.
Compaction/Cementation
(Lithification)
Hardening of moist sediment by pressure.
Heat and Pressure
Partial melting of rock by heat of magma chambers or
pressure from plate collisions.
Rock Texture
Classified By:
Size of grains- larger or coarse to small or none.
Shape of grains- rounded or jagged
Pattern of grains- layered or non-layered
Section 4-2 Igneous Rocks
Where and how do igneous rocks form?
From cooled lava or magma around volcanic
regions.
Igneous rocks are called Intrusive or Extrusive based
on where they are formed.
Igneous video 1
Igneous video 2
Intrusive Igneous rocks
Intrusive rocks cool slowly and crystals have time to grow
larger.
Extrusive Rocks
Extrusive rock crystals are small because rock was not given enough
time to cool.
Magma types
Basaltic(MAFIC)- thin, fast moving lava rich
in iron and magnesium. Forms dark colored
rocks. (Much like maple syrup)
Granitic (FELSIC)- thick, slow moving
magma rich in silicon and oxygen. Forms
light colored rocks (More like molasses)
Andesitic- magma with a mixed
composition of basaltic and granitic.
Classifying Igneous rock
1. Look at crystal size. Intrusive or Extrusive?
2. Look at color of rock. Basaltic, Granitic or Andesitic?
4-3 Sedimentary Rocks
75% of all Rocks on Earth’s surface are sedimentary.
Sedimentary rocks contain fossils and give clues to what
happened in Earth’s history.
Weathering and Erosion breaks particles into fragments.
Particles are either cemented or compacted together to
form rock.
Most rocks found in our area are Sedimentary!!!
Sedimentary video
Types of Sedimentary Rocks
Clastic- rock formed from broken fragments compacted
and cemented.
Sediment Sizes
Clastic Sedimentary rocks are classified by sediment
size in the rock.
Particles move into an ocean or
lake and settle out by particle
size and density.
Largest particles near
shoreline, finer and
smaller farther out.
Sedimentary video #2
Key clastic Sedimentary rocks
shale
sandstone
Rank the particle sizes of the rocks.
conglomerate
Chemical Sedimentary Rocks
Formed from precipitated solution or evaporated solution.
Usually have a smooth texture.
Limestone
Chert
Rock salt
Organic Sedimentary rocks
Compacted remains of once living things such as
plants, shells, and microscopic organisms
Coal
Coquina
Fossil-rich limestone
Section 4-4 Metamorphic Rocks
Classes of Metamorphic Rock
•Foliated- mineral grains pressed into layers. Gives rock a
“banded” appearance.
•Non-foliated- rock is “baked” and minerals re-arrange
Metamorphic video 1
Which is Foliated/Non-Foliated?
Formation
Regional metamorphism= heat
and pressure (extreme folding)
Contact metamorphism= heat
(surrounding rock cooked)
Metamorphic video #2
Mother Rocks
Protolith- The rock that a metamorphic rock was formed from. The
“Mother Rock”
Sandstone- Quartzite
Limestone- Marble
Granite- Gneiss
Coal Formation
PEAT
ANTHRACITE
LIGNITE
BITUMINOUS
TYPE OF COAL FORMED DEPENDS ON THE AMOUNT
OF PRESSURE APPLIED TO MATERIAL!!!!