1. Introduction to Lithosphere
Chapter 13
Introduction to Lithosphere

2. Introduction to Landform Study
The Unknown Interior (deepest mine shaft only 2.4 miles deep)
Composition of the Crust
Critical Concepts
The Study of Landforms
Geomorphic Process, Scale, and Pattern

3. The Unknown Interior Earth’s diameter 8000 miles Crust = 5-25 miles
Mantle = 1800 miles
Outer Core =1300 miles
Inner Core = radius 900 miles

4. Crust Outermost shell 25 mi deep = continent 5 mi deep = ocean
Base of crust is known as “Moho”
Altogether crust = < 1% of Earth’s volume
Circumference Earth = 25,000 miles

5. Mantle Extends 1800 miles into interior of Earth
Constitutes 84% vol. & 66% total weight
Mantle divided into 3 parts:
Lithosphere = mantle + crust = uppermost
Asthenosphere = weak sphere = hot rocks
Mesosphere = deep mantle = rigid rocks

6. Outer Core Inner Core Beneath mantle Molten liquid
Extends 3100 miles into interior of Earth
Inner Core
Solid and very dense mass
Radius of 900 miles (from core outward)
Inner and Outer Cores are made of iron/nickel or iron/silicate
Both constitute 15% volume and 32% weight

7. Earth’s Layers

8. Earth’s Interior
900

9. The Layers

10. Earth’s Crust and Mantle
Crust is a broad mixture of rock types
Mantle is largest of 4 shells
Mantle has 3 sections:
crust & lithosphere
Aesthenosphere
mesosphere
The mesosphere extends downward to 1800 miles

11. Composition of the Crust
Minerals, Rocks, and Bedrock
Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks
Rock Classes – uneven distribution of the 3 classes

12. Naturally occurring minerals, which contribute to the soil content

13. FYI: Man made minerals

14. Minerals natural compounds formed through geological processes
"mineral" encompasses not only the material's chemical composition but also the mineral structures
range in composition from pure elements and simple salts to very complex silicates

15. Bedrock Solid rock at surface is outcrop
The solid rock that underlies all soil or other loose material
The rock material that breaks down to eventually form soil.
Solid rock at surface is outcrop
Most is buried beneath sediments
Sedimentary rock composes most of lithosphere

16. Igneous Rock Rock formed when molten (melted) materials harden
The original rock
It all started here
Extrusive - intrusive

17. Intrusive Igneous Extrusive Igneous
Millions and even billions of years ago molten rock was cooling and thus hardening into igneous rocks deep under the surface of the Earth. These rocks are now visible because mountain building has thrust them upward and erosion has removed the softer rocks exposing the much harder igneous rocks. These are called intrusive igneous rocks
When lava reaches the surface of the Earth through volcanoes or through great fissures, the rocks that are formed from the lava cooling and hardening are called extrusive igneous rocks

18. Extrusive Igneous Intrusive Igneous
Breaks surface as lava and then cools and hardens
Intrusive Igneous
Magma cools and hardens below surface and then is exposed above surface by mountain building

19. Sedimentary Rock Consolidation of deposited particles
formed by the hardening of material deposited in some process
most commonly sandstone, shale, and limestone
Sedimentary rocks are formed from the breaking apart of other rocks (igneous, metamorphic, or sedimentary rocks) and the cementation, compaction and recrystallization of these broken pieces of rock.

20. Formation of Sedimentary Rocks
Sedimentary rocks are formed in two ways:
1. by pressing together or compacting loose particles which have been deposited on land or in water bodies such as seas or lakes. These loose particles are called sediments. 2. by the crystallization of dissolved minerals.
Compaction
Cementation

21. By compacting sediments
By crystallization from dissolved minerals

22. Sedimentary Strata

23. Metamorphic Rocks Originally igneous/sedimentary Changed by heat/pressure
Metamorphic rocks are sedimentary or igneous rocks that have been altered by heat and/or pressure. As they are derived from previously existing igneous, sedimentary or even metamorphic rock, their appearance is variable. They are identified by the types of minerals they contain and their texture

24. Foliation
Layering formed as a consequence of the alignment of mineral grains, or of compositional banding in a metamorphic rock.

25. The Rock Cycle

26. Distribution of Rock Classes

27. Geologic
Time
Figure 13-18

28. Geomorphic Processes