ROCKS N MINERALSRockin in the USA!!!!
3 Major Rock Types
1. Igneous Rock 2. Sedimentary Rock 3. Metamorphic Rock
Igneous Rock Means “From Fire” Forms when magma cools
and hardens Lava rock
2 Groups of Igneous Rocks 1. Intrusive Igneous Rock:
Cooling of magma deep below the earth’s surface.Have large crystalline grains
2. Extrusive Igneous Rock: Rapid cooling of lava on the earth’s surface.Fine grained rock
Igneous Texture Size of the crystalline grains in rock Depends on rate of cooling
Slower cooling = more grainsGranite
Intrusive have larger grains Porphyry: has a mixture of large and
small crystals Igneous rocks cooled very fast will look
like glass. Obsidian
Igneous Composition Determined by composition of
magma the rock was formed from
Divided into 3 categories:1. Felsic2. Mafic3. Diorite
Felsic High in silica Light coloring of their mineral
crystals Ex. Granite and obsidian
Mafic Low in silica but rich in iron Have dark colored mineral crystals Ex. Basalt and gabbro
Diorite Include little or no quartz Contain coarse grain diorite
Warm Up Questions??? 1. What are the three main types of
rocks? 2. Slow cooling of a rock is called
____________. 3. Fast cooling of a rock is
called______________. 4. Please name one rock which cools
slowly. 5. Please name one rock that cools
quickly. 6. Which rocks make up continental
and oceanic crust?
Forces of nature break down rocks into small particles called sediment
Wind, water, and ice
Weathering
Erosion Movement of
particles of rock due to weathering.
Particles are loosened and moved
Sedimentary Rocks Rocks are broken down due to
erosion Very small rock sediments are
collected in streams, rivers, and oceans.
Sediments compact Harden and form new rocks
Compaction and Cementation
Processes that form sedimentary rocks
Various types of rock sediments accumulate
Compact and become thick layers
Weight and pressure cement sediments into solid rock
Minerals left between sediments act as cement
Sedimentary Rock Types 1. Clastic: separate fragments
become compacted into solid rock.
2. Chemical: Form from dissolved minerals
3. Organic: form from the remains of organisms.
Clastic Sed. Rocks 1. Conglomerate: Rock
composed of round, pebble sized fragments.
2. Breccia: Rock composed of pebble sized fragments with sharp, angular corners.
Chemical Sed. Rocks Minerals
dissolve in water
Leave behind deposits
Dry and harden into rocks
Ex. Rock Salt
Organic Sed. Rocks Formed from
the remains of living things
Ex. Coal, and Chalk
Stratification Layering of
sedimentary rocks
Occurs when there is a change of sediment being deposited
Usually found in sedimentary rocks
Animal or plant is buried Sediments pile up and harden Hard bones and teeth dissolve This leaves an impression in the
rock
Fossils
Metamorphic Rock Changing of one type of rock
to another by heat, pressure, and chemical processes.
Form deep beneath the surface
All metamorphic rock is formed from existing igneous, sedimentary, or metamorphic rock.
Metamorphic Cont. Heat and
pressure semi melt the rock and cause certain minerals to change into other chemicals.
Parallel bands running through the rock
Classification of Met. Rock Classified according to structure Foliated: have visible parallel
bands Mineral bands separate by density under pressure
Slate, schist, and gneiss Unfoliated: without visible
bandsQuartzite and marble
Rock Cycle Any of the three major types
can change into another type. Geological forces have the
ability to change one rock type to another.
Rocks are recycled throughout these three forms
Rock Cycle Explained
Rock Cycle Fire
Question 1 Please explain how igneous
rock can turn into sedimentary rock during the rock cycle.
Question 2 Please explain how
sedimentary rock turns into igneous rock.
Question 3 Please explain how sedimentary
rock can turn into metamorphic rock.
Question 4 Please explain how it is possible
for metamorphic rock to become another metamorphic rock.
Mr. Parr Rock Cycle
Mr. Lee Rock Cycle
Minerals
Minerals A natural, inorganic,
crystalline solid. The basic elements of the
earth’s crust. Over 3,000 total 20 Common
Characteristics of Minerals Each mineral has specific properties Mineral Properties:
1. Color2. Luster3. Streak4. Cleavage and Fracture5. Hardness6. Crystalline Shape7. Density8. Magnetism
Color Unreliable identification Some minerals have distinct
colors BUT Some minerals will change color
when exposed to different elements.
Luster Light refracted from the surface
of a mineral Metallic and nonmetallic luster Glassy Waxy Pearly Brilliant- Diamond
Streak Color of the mineral in
powder form Rub the mineral against a
ceramic tile and observe the streak
May not be same color as a larger piece of the mineral
Cleavage and Fracture Cleavage: How a mineral
will break along its flat surfaces.
Fracture: Irregular breaking of a mineral.
Depends on Bonding of elements
Magnetism Is the
mineral magnetic???
Hardness The ability of a mineral to resist
scratching Determined by the Mineral
Hardness ScaleScale of 1-10 (10=hardest)
Mineral Hardness Scale 1. Talc 2. Gypsum 3. Calcite 4. Fluorite 5. Apatite 6. Orthoclase 7. Quartz 8. Topaz 9. Corundum 10. Diamond
The Gypsy Came From Asia Often Questioning The Crazy Directions
• Finger Nail (H = 2.5)• Penny (H = 3)• Knife Blade (H = 5.5)