Warm Up 1.How are rocks broken down? 2.How are rocks formed? 3.List the 3 types of rocks produced by the rock cycle.

Geosphere  Just like the spherical layers in an onion, the Earth has multiple layers that serve different purposes.  Layers by Composition  The crust is less than 1% of Earth by mass. The two types are oceanic crust and continental crust.  The mantle is hot, ultramafic (filled with magnesium and iron) rock. It represents about 68% of Earth's mass.  The core is mostly iron metal. The core makes up about 31% of the Earth.  Layers by Mechanical Properties  The lithosphere is composed of both the crust and the portion of the upper mantle and behaves as a brittle, rigid solid.  The asthenosphere is partially molten upper mantle material and

Lesson 2: The Rock Cycle How rocks are created and destroyed……then created again.

Key Terms  Igneous  Sedimentary  Metamorphic  Lava  Magma  Foliation  Deposition

Major Rock Groups 1.Igneous  Formed when rocks melt into magma or lava and then cool  Intrusive: (plutonic) slow cooling and crystallization; when magma within the lithosphere  Extrusive: (volcanic) quick cooling at the surface; when lava cools on the surface of the lithosphere 5

Fig. 2.9 MAGMA

Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form.

9 Major Rock Groups 2.Sedimentary  Formed at the Earth’s surface when other rocks are weathered, eroded, deposited,  Clastic (Mineral Fragments or grains, clays)  Chemical (crystalline chemical/biochemical precipitates)

About Metamorphic Rocks…  Metamorphic is Greek for…  change in form

11 Major Rock Groups 3.Metamorphic  Changed by pressure, temperature and fluids.  When rocks bend or partially melt due to strong forces in the lithosphere  Do not melt

Classification of Metamorphic Rocks…  Foliated…  wavy layers and bands that are caused by minerals with flat crystals that form long axes perpendicular to the pressure GneissSchistSlate

13 MAGMA Crystallization IGNEOUS

14 MAGMA IGNEOUS Plutonic Crystallization

15 MAGMA Volcanic IGNEOUS Plutonic Uplift Crystallization Weathering

16 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT Uplift Crystallization Weathering SEDIMENT

17 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY Uplift Crystallization Weathering Erosion Transport Deposition

18 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY Uplift Crystallization Weathering Erosion Transport Deposition

19 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Uplift Burial Increased P&T Crystallization Weathering Erosion Transport Deposition

20 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Uplift Burial Increased P&T Melting Crystallization Weathering Erosion Transport Deposition Can you see any shortcuts?

21 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Uplift Burial Increased P&T Melting Crystallization Weathering Erosion Transport Deposition

The rock cycle demonstrates the relationships among the three major rock groups It is powered by the interior heat of the Earth As well as earth’s momentum and… The energy from the sun It involves processes on the Earth’s surface as well as the Earth’s interior It connects the “hydrologic cycle” with the “tectonic cycle”. In Conclusion…

24 MAGMA Volcanic IGNEOUS Plutonic SEDIMENT SEDIMENTARY METAMORPHIC Uplift Burial Increased P&T Melting Crystallization Weathering Erosion Transport Deposition

The Rock Cycle…  How are igneous rocks formed?  By melting, cooling, and crystallization  What happens to igneous rocks that undergo weathering and erosion?  They become sediments  How do sediments become sedimentary rocks?  By deposition, burial, compaction, and cementation

The Rock Cycle (continued)…  What forces cause sedimentary rocks to be transformed into metamorphic rocks?  Heat and pressure – without melting!  How can metamorphic rock be transformed into igneous rock?  By melting, cooling and crystallization of magma  How can sandstone be transformed into sediment?  By erosion

The Rock Cycle – A Diagram