Glacial Features & Rock Families

• Erratic: A large rock or boulder that differs from the surrounding rock and was transported from a distant location by glacial ice.
• Moraine: A mass of rocks and sediment carried down and deposited by a glacier, typically as ridges at its edges or extremity.
• Converging Plates: Tectonic plates that move towards each other, resulting in collisions.
• Diverging Plates: Tectonic plates that move away from each other, resulting in new crust formation.
• Frost Wedging: A physical weathering process where water penetrates cracks in rocks, freezes and expands, causing the rock to fracture.
• Convection Currents: The transfer of heat through a fluid (liquid or gas) caused by differences in density.

Rock Families

• Igneous rocks form from the cooling and solidification of magma or lava.
• Sedimentary rocks form from the accumulation and cementation of sediments.
• Metamorphic rocks form when existing rocks are changed by heat, pressure, or chemical processes.
• Examples of each type: Granite (igneous), Sandstone (sedimentary), and Marble (metamorphic).
• Extrusive igneous rocks cool quickly on the Earth's surface, resulting in small crystals.
• Intrusive igneous rocks cool slowly beneath the Earth's surface, resulting in large crystals.

Wegener’s Theory of Continental Drift

• Alfred Wegener’s Theory of Continental Drift states that the continents were once joined together in a single landmass called Pangaea and have since drifted apart.
• Evidence #1: The continents fit together like puzzle pieces
• Example: The coastlines of South America and Africa match.
• Evidence #2: Fossil evidence
• Example: Similar fossils found on different continents.
• Evidence #3: Rock and mountain correlation
• Example: Similar rock formations and mountain ranges found on different continents
• Evidence #4: Paleoclimate data
• Example: Evidence of past glaciations in areas that are now tropical

Tectonic Plates

• Tectonic plates are pieces of Earth’s crust and uppermost mantle (lithosphere) that move and interact, causing earthquakes, volcanic activity, and mountain building.

Layers of the Earth

• Inner Core: Solid, made of iron and nickel, does not play a role in plate tectonics.
• Outer Core: Liquid, made of iron and nickel, does not play a role in plate tectonics.
• Mantle: Solid, made of silicate rocks, plays a role in plate tectonics due to convection currents.
• Asthenosphere: A highly viscous, mechanically weak and ductile region of the upper mantle, it lies below the lithosphere, at depths between approximately 80 and 200 km below the surface, the athenosphere plays a role in plate tectonics
• Lithosphere: Solid, made of the crust and upper part of the mantle, plays a direct role in plate tectonics.

Types of Weathering

• Physical Weathering: The disintegration of rocks without any chemical change.
• Example 1: Frost wedging, where water freezes and expands in cracks, breaking rocks apart.
• Example 2: Abrasion, where rocks collide and wear each other down.
• Chemical Weathering: the decomposition of rocks through chemical reactions.
• Example 1: Oxidation, where minerals react with oxygen, causing rust.
• Example 2: Acid rain, where pollutants dissolve rocks.