ANATOMY
OF THE
EARTH
Elements, Minerals, Rocks
• Elements
– Pure Substances
– Gold
– Oxygen
• 50% of Earth’s Crust
– Silicon
• 25% of Crust
Minerals (pg. 60)
• Mixture of Elements
– SiO2 = Quartz
Rocks
(pp. 78-79)
• Mixture of Minerals
– Granite = Quartz & other mins.
Categories of
Rocks (pp. 80-81)
• Igneous
• Sedimentary
• Metamorphic
Igneous Rocks
• When Magma (molten rock)
cools & solidifies
• Magma above ground..
Lava
Igneous Rocks
• 2 Factors Determine Type of Ig. Rock
– Where Magma Solidifies
– Composition of Magma
Where Magma Solidifies
• Underground
• Slow Cooling
• Large Mineral
Crystals
• “Intrusive” or
“Plutonic”
• Above Ground
• Fast Cooling
• Small Mineral
Crystals
• “Extrusive” or
“Volcanic”
Where Magma Solidifies
Underground • Above Ground
Slow Cooling • Fast Cooling
Large Mineral • Small Mineral
Crystals
Crystals
“Intrusive”
• “Extrusive” or
“Volcanic”
Light-Colored
Minerals
Low Density
e.g., Quartz
• Dark Minerals
Dense
Granite (pg. 82)
• Yosemite Nat’l Park
Granite
• Sierra Nevada
Where Magma Solidifies
Underground • Above Ground
Slow Cooling • Fast Cooling
Large Mineral • Small Mineral
Crystals
Crystals
“Intrusive”
• “Extrusive” or
“Volcanic”
• Felsic Minerals
Light-Colored
Lo Density
e.g., Quartz
• Mafic Minerals
Dark
Dense
Basalt (pg. 84)
• Hawaii
Sedimentary Rocks
• 3 Types
– Clastic
– Chemically Precipitated
– Organic
Clastic Sed. Rocks
1. Rock breaks down into sediment
2. Sed. is transported
Clastic Sed. Rocks
3. Sed is deposited in layers
4. Lithified (cemented) into rock
Clastic Sed.
Rocks (pg. 93)
• Sand  Sandstone
• Clay  Shale
Grand Canyon 
Chemically Precipitated Sed. Rocks
• Deposited from Salty Water
– When Salt H2O Evaporates
• Rock Salt (pg. 94)
Chemically Precipitated Sed. Rocks
• Limestone
Calcium Carbonate (CaCO3)
– Forms on Ocean Floor
Chemically Precipitated Sed. Rocks
• Limestone
– Also in Caves
Chemically Precipitated Sed. Rocks
• Tufa Limestone
– Forms on Lakebeds (underwater)
• Mono Lake, CA
Tufa Formation
• Lake water is salty
– Has Carbonate (CO3)
Tufa Formation • Spring H2O thru lake bed
– Brings Calcium (Ca)
– Ca Combines with CO3
– Tufa grows upward
Tufa on Dry Land…Why?
Organic Sed. Rocks
• From Layers of
Plant/Animal Tissues
• “Fossil Fuels”
– Coal
– Peat
Metamorphic
Rocks (pg. 87)
• “Changed”
– By Heat & Pressure
– Usually Dense
• Granite  Gneiss
(“nice”)
• Limestone into…
Marble
Sandstone  Quartzite (pg. 89)
• Shale  Slate
• Slate  Schist
(pp. 88, 89)