Princeton Review

Introduction

  • Resource: Strictly defined as any substance, capability (work performed by humans or animals), or other asset that is available in a supply that can be accessed and drawn on as needed.

  • Solid Earth: The Earth’s solid, rocky outer shell.

    • The movement of tectonic plates, volcanoes and earthquakes, and the different types of rock.

    • Lithosphere: The upper shell of the solid Earth, the part that interacts most with the other spheres.

  • Pedosphere: Commonly known as soil

  • Atmosphere: The envelope of gases that surrounds the Earth

  • Hydrosphere: The Earth’s oceans and freshwater bodies

  • Biosphere: Comprises all living organisms that inhabit the planet and drwa on the physical resources of the other 4 spheres.

  • History of the Earth: 4.5 - 4.8 billion years old.

Geologic Time Scale

  • Currently in the Holocene Epoch

  • Quarternary and Tertiary aree the two most recent geologic periods.

  • Non-avian dinosaurs lived during the Mesozoic Era.

  • Precambrian eons represent vast majority of geologic time scale.

  • Next epoch will be called the Anthropocene.

Solar System

  • Earth is the third planet from the Sun.

  • Total of eight known and recognized planets.

The Solid Earth

  • Earth is made of three concentric zones of rocks that are solid or liquid (molten).

  • Core: innermost zone, made of a solid inner core and a molten outer core.

    • Inner core: Composed mostly of nickel and iron and is solid due to pressure from overlying matter.

    • Outer core: Composed mostly of iron, mixed with nickel and lighter elements, semi-solid due to lower pressure.

  • Mantle: Made mostly of solid rock.

  • Asthenosphere: Slowly flowing rock that lies near the top of the mantle.

  • Lithosphere: A thin, rigid layer of rock that is the Earht’s outer shell. It includes the rigid upper mantle above the asthenosphere and the crust, the solid surface of the Earth.

Tectonic Plates

  • Pangaea: A theory of a supercontinent that was joined together during the Paleozoic and Mesozoic Eras.

  • Tectonic plates: Large pieces of lithosphere that composes Earth’s crust that slowly move over the mantle of the Earth.

    • Nazca plate: A tectonic plate that consist only of ocean floor.

  • Plate boundaries: Edges of plates.

  • Convergent boundary: Two plates are pushed toward and into each other. One of the plates slides beneath the other, pushed deep into the mantle.

  • Divergent boundary: Two plates move away from each other. This creates a gap between plates that may be filled with rising magma (molten rock). When this magma cools, it forms new crust.

  • Transform fault boundary: Two platees slide against each other in opposite directions.

  • Subduction:Heavy ocean plate is pushed below the other plate and melts as it encounters the hot mantle.

  • Orogeny: Uplifting of plates that form large mountain chains as converging continent-continent boundaries crunch into each other (Himalayas).

Volcanoes and Earthquakes

  • Volcanoes: Mountains formed by pressure from magma rising from the Earth’s interior.

    • Separated into active volcanoes, dormant volcanoes, and extinct volcanoes.

  • Subduction zones: Occur at convergent boundaries where subducting plate is recycled into new magma, which rises through the overlying plate to create volcanoes inland.

  • Rift valleys: Occur at divergent boundaries, usually between two oceanic plates. New ocean floor is formed as magma fills in the gap between separating plates. Thick magma rising fis made of basaltic minerals and forms pillow lava upon contact with the cold ocean water.

  • Hot spots: Do not form at plate boundaries - in the middle of tectonic plates, in locations where columns of unusually hot magma melt through the mantle and weaken the Earth’s crust.

    • Volcanoes over oceanic hot spots are basaltic, resulting in milder eruptions.

    • Volcanoes over continental hot spots are characterized by rhyolitic rocks, which produce more violent eruptions.

Types of Volcanoes

  • Shield volcanoes: Broad bases and tall with gentle slopes. Form over oceanic hot spots and usually have mild eruptions with slow lava flow.

    • When water enters the vent, they can be very explosive, forming pyroclastic flows (fluidized mixture of hot ash and rock).

  • Composite volcanoes: Broad bases and tall with steep slopes. They are formed at subduction zones and associated with violent eruptions that eject lava, water, and gases as superheated ash and stones.

  • Cinder volcanoes: Small, short, steeply sloped cones. Form when molten lava erupts and cools quickly in the air, hardening into porous rocks (cinders or scoria) that fracture as they hit the Earth’s surface. Generally form near other types of volcanoes.

  • Lava domes: Small and short with steep slopes and rounded tops. Formed from lava that is too viscous to travel far but hardens into dome shape. Occurs near or even inside other types of volcanoes.

Earthquakes

  • Earthquakes: Result of vibrations (due to sudden plate movements, such as stress overcoming a locked fault) deep in the Earth that release stored energy.

    • Earthquakes often occur as two plates rapidly slide past one another at a transform boundary.

  • The focus of the earthquake is the location at which it begins within the Earth, and the initial surface location of the event is the epicentre.

  • Tsunamis: Very large ocean waves, or chains of waves, caused by the movement of the Earth during an earthquake or volcanic eruption.

The Rock Cycle

  • The Rock Cycle: Time, pressure, and Earth’s heat interact to create igneous, sedimentary, and metamorphic rock.

    • Igneous rock: Results when rock is melted (by heat and pressure below the crust) into liquid, resolidifies when cooled. Molten rock (magma) comes to the surface of the earth as lava, then cools into solid igneous rock, e.g. basalt.

    • Sedimentary rock: Formed as sediment (eroded