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ROCKS

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Title: ROCKS


1
ROCKS
2
What is a rock?
3
What is a rock?
  • Made of entirely one mineral or several minerals.
  • Could contain organic matter (composed of living
    material, usually carbon based).
  • The chemical make-up of the rock may vary from
    one sample to another.

4
Types of Rocks
  • What are the three classes of rocks?

5
Types of Rocks
  • What are the three classes of rocks?
  • 1. Igneous Rocks
  • 2. Sedimentary Rocks
  • 3. Metamorphic Rocks

6
Igneous Rocks
  • Name comes from the Latin word ignis meaning
    from fire.
  • Formed when super hot magma or lava cools.
  • There are seven different classes based on
    chemical composition of the igneous rock.

7
Types of Igneous Rocks
  • Extrusive Igneous Rocks
  • Formed from lava that quickly solidifies at the
    cooler surface.
  • Produces fine-grained rocks.
  • Ex. basalt and rhyolite

david-amador.com
geology.com
8
Types of Igneous Rocks
  • Intrusive Igneous Rocks
  • Trapped magma under the crust solidifies slowly.
  • Intrusive rocks are composed of larger crystals
    because form slower.
  • Larger crystals give these rocks a rougher
    texture
  • Ex. granite
  • Mount Rushmore is carved from granite in the
    Black Hills of South Dakota.

Mount Rushmore is carved from granite in the
Black Hills of South Dakota.
9
Igneous Rock
  • The most common known igneous rock is granite.
  • It is composed almost entirely of feldspar and
    quartz

10
Igneous Rocks Mafic vs. Felsic
  • Felsic chemically composed of potassium,
    feldspar, and large amounts of quartz.
  • Mafic chemically composed of iron and
    magnesium, and smaller amounts of quartz.

csmres.jmu.edu
11
Bell Ringer Rocks
  • What is the difference between intrusive and
    extrusive igneous rocks?
  • T or F Intrusive igneous rocks are composed
    of larger crystals then extrusive igneous rocks.
  • Would mafic or felsic magma be magnetic? Explain
    your answer.

12
Igneous Rock Formations
  • Extrusive Igneous Structues
  • volcanoes
  • Intrusive Igenous Structures
  • batholiths
  • laccoliths
  • sills
  • dikes

indiana.edu
13
Sedimentary Rocks
  • All sedimentary rocks are made of materials
    called sediments deposited by natural and
    chemical processes.
  • Sediments become cemented or compacted together
    over time forming a solid rock

Uluru (Ayers Rock) in Australia, the world's
largest monolith, is made of sandstone.
14
Types of Sediments
  • Tiny grains of sand
  • Broken pieces of rock along the bottom of a
    stream
  • Fragments of seashells
  • Layers of mud
  • Organic matter (plant and animal remains)

15
Sediments and Sedimentary Rocks
  • Gravity, water, or wind carries them to a
    destination.
  • Sediments deposit in layers over time. (strata
    layers)
  • Loosely deposited sediments eventually form a
    solid rock by
  • 1.Compaction sediments squeezed together by
    gravity/pressure.
  • 2. Cementation sediments glued together by
    minerals deposited by water.

16
Sedimentary Rock
  • The most common sedimentary rock is limestone.
  • Develops from living remains (shells, mollusks)
  • Coal is another example of a sedimentary rock
    derived from organic remains.

17
Sedimentary Rock
Ripple marks formed in the sand by wind
  • Often preserve some characteristics from which
    they were formed.
  • Ripple marks formed in the sand will appear in
    the rock formed from the sand deposits.

18
Sedimentary Rocks
  • The source of most fossil remains.
  • The age of a rock can be determined by studying
    the fossils within it.(Radiometric Dating)
  • Identify when prehistoric organisms and
    vegetation thrived and became extinct.

Fossilized Leaves
19
Sedimentary Rocks
  • The diverse colors within the sedimentary layers
    (strata) gives scientists an idea of their
    chemical make-up.
  • The red and pink bands in the Grand Canyon
    exhibit the iron found in the sediment.

20
Sedimentary Rocks Location
  • Sedimentary rocks cover almost all of the ocean
    floor and about three-fourths of Earth's surface
    land area.

21
Metamorphic Rock
  • Metamorphism change in the chemical make-up of
    rocks
  • Heat, pressure, and hot fluids cause rocks to
    change into other rocks.
  • Where would this most likely occur?

22
Metamorphic Rock
  • Heat, pressure, and hot fluids cause rocks to
    change into other rocks.
  • Where would this most likely occur? within the
    Earth
  • at subduction zones

23
Metamorphic Rock
Formed from compression of Tectonic plates
The geologic processes that created the North
Cascades changed the original rock into
metamorphic rock.
24
Types of Metamorphic Rock
  • Slate is a common form that is easily split into
    slabs
  • Gneiss (pronounced nice) contains light and
    dark bands
  • Granite is also a common type

25
The Rock Cycle
  • Almost all of the rocks that compose the Earths
    crust today are made of the same stuff as the
    rocks that dinosaurs and other ancient life forms
    walked, crawled, or swam over. While the
    stuff(matter) that rocks are made of has changed,
    the rocks themselves, have not. Over time rocks
    are recycled into other rocks.

26
The Rock Cycle
27
The Rock Cycle
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