Unit 2 test review (CONCEPT CARDS)

Layers of the Earth (outer → inner)

Crust → Mantle → Outer Core → Inner Core

Two types of crust

Continental crust (thick, less dense, older) and Oceanic crust (thin, dense, younger)

Magma vs Lava

Magma is molten rock beneath Earth’s surface and Lava is magma that reaches the surface and forms igneous rock when cooled.

Three types of rocks

Igneous: cooling of magma/lava (Basalt, granite). Sedimentary: compaction and cementation of sediments (Limestone, sandstone). Metamorphic: heat and pressure on existing rock (Marble, slate).

Longitude

Imaginary vertical lines running north–south. Measures distance east or west of the Prime Meridian. Determines time zones.

Latitude

Imaginary horizontal lines running east–west. Measures distance north or south of the Equator. Determines climate zones. Mnemonic: “Latitude = Flatitude.”

Geologists’ role

Study Earth’s materials, structure, and history. Predict natural disasters, find resources, and study Earth’s evolution.

Continental Drift (basic)

Alfred Wegener (1912) proposed all continents once formed Pangaea and drifted apart over time. Evidence: matching fossils, rocks, coastlines.
Crust creation

Plate collision

Continental plates crash and uplift to form mountain chains like the Rockies.

Plates grinding

Plates sliding past each other cause earthquakes.

Plate subduction

One plate slides beneath another, creating volcanic activity