BETAEsta plataforma está em desenvolvimento ativo; há bugs, recursos faltando e risco de perda de dados. Obrigado pelo seu apoio!

The rock cycle and Earth's materials

Aprenda jogando

Responda a estas perguntas para ganhar energia, depois pesque e explore. Sem precisar de conta.

Para professores: slides de aula, resumos de revisão prontos para usar de The rock cycle and Earth's materials (NGSS Middle School Science, Earth and Space Science) — use na sua aula ou rode o tópico como atividade interativa de turma que seus alunos jogam como um jogo ao vivo.

Notas de aula

Earth's Layers and the Lithosphere

  • The Earth is made up of concentric layers: crust, mantle, and core.
  • The lithosphere consists of the crust and the brittle upper part of the mantle.
  • The crust has two types: continental crust (under continents) and oceanic crust (under oceans).
  • The core has an inner core (solid) and an outer core (liquid).
  • The mantle is divided into lower mantle and upper mantle.
  • The lithosphere, mantle, and core together are called the geosphere.

Cross-section of Earth's layers: crust, mantle, and core, showing oceanic and continental crust, the lithosphere, upper and lower mantle, the liquid outer core, and the solid inner core.

Cross-section of Earth's layers: crust, mantle, and core, showing oceanic and continental crust, the lithosphere, upper and lower mantle, the liquid outer core, and the solid inner core.

The Rock Cycle: Overview

  • The rock cycle is a continuous process where rocks form, break down, and re-form over long periods.
  • Rocks are classified into three types: igneous, sedimentary, and metamorphic.
  • The cycle involves processes like weathering, erosion, deposition, compaction, cementation, melting, and cooling.
  • Energy for the rock cycle comes from the sun (surface processes) and Earth's interior (heat and pressure).
  • Not all rock on Earth is recycled; thousands of tons of rock fall from space each year.

The rock cycle: magma cools to form igneous rock; weathering, erosion and deposition form sediment that compacts into sedimentary rock; heat and pressure form metamorphic rock; melting returns rock to magma.

The rock cycle: magma cools to form igneous rock; weathering, erosion and deposition form sediment that compacts into sedimentary rock; heat and pressure form metamorphic rock; melting returns rock to magma.

Formation of Sedimentary Rocks

  • Sedimentary rocks form from sediments – particles of pre-existing rocks or once-living organisms.
  • Weathering breaks down rocks into smaller pieces via wind, water, heat, and cold.
  • Erosion transports sediments and deposits them in oceans, lakes, and rivers (deposition).
  • Layers of sediment accumulate, and compaction from overlying layers squeezes them together.
  • Cementation binds sediments with minerals to form solid rock.
  • Examples include sandstone, limestone, dolomite, coal, shale, and conglomerate.
  • Fossils are often found in sedimentary rocks because organisms get buried in sediment and preserved.

Formation of sedimentary rocks from land and organic material

Formation of sedimentary rocks from land and organic material

Formation of Metamorphic Rocks

  • Metamorphic rocks form when existing rocks (igneous or sedimentary) are exposed to high heat and pressure deep underground.
  • They do not melt completely; instead, minerals change and crystals are squashed, altering the rock's texture and composition.
  • The original rock is called the parent rock; the new rock is the daughter rock.
  • Examples include slate (from shale), marble (from limestone), soapstone, and quartzite (from sandstone).
  • Metamorphic rock can be exposed at the surface when overlying layers are eroded away.

Parent rock and daughter rock: shale (a sedimentary rock) metamorphoses into schist under heat and pressure.

Parent rock and daughter rock: shale (a sedimentary rock) metamorphoses into schist under heat and pressure.

Formation of Igneous Rocks

  • Igneous rocks form when magma (molten rock underground) or lava (magma on the surface) cools and solidifies.
  • Intrusive igneous rocks cool slowly beneath the surface, forming large crystals (e.g., granite).
  • Extrusive igneous rocks cool quickly on the surface, forming small crystals or glassy textures (e.g., basalt, pumice).
  • The amount of trapped gas affects rock texture; rapid cooling traps gas, creating holes (e.g., pumice).
  • Examples include basalt (most common, oceanic crust), granite, and pumice.

Intrusive igneous rock cools slowly underground into large crystals; extrusive igneous rock cools quickly at the surface into fine crystals.

Intrusive igneous rock cools slowly underground into large crystals; extrusive igneous rock cools quickly at the surface into fine crystals.

Key Processes in the Rock Cycle

  • Weathering: breakdown of rocks by wind, water, heat, and cold.
  • Erosion: transport of weathered materials by wind, water, ice, or gravity.
  • Deposition: settling of sediments in new locations.
  • Compaction: squeezing of sediments under pressure.
  • Cementation: binding of sediments by minerals to form solid rock.
  • Melting: transformation of rock into magma under high temperatures.
  • Cooling and crystallization: formation of igneous rocks from magma/lava.

Minerals in Rocks

  • Rocks are made of minerals – naturally occurring solid substances with a regular crystal structure.
  • Common minerals include quartz and feldspar, the two most abundant minerals in Earth's crust.
  • Different combinations of minerals create different rock types.
  • Minerals are important resources; for example, copper is extracted from ore minerals like chalcocite and chalcopyrite.
  • Iron combines with oxygen to form haematite, an important iron ore often found in sedimentary rocks.

Chalcopyrite crystals, a copper-bearing mineral found in rock.

Chalcopyrite crystals, a copper-bearing mineral found in rock.

Energy Flow and Matter Cycling

  • The rock cycle illustrates the relationship between energy flow and matter cycling.
  • Solar energy drives surface processes like weathering and erosion.
  • Earth's internal heat drives processes like melting and metamorphism.
  • Rocks continuously change from one type to another through these energy-driven processes.

Slides

Sign up free to view the lesson slides

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

Questões de prática

Prévia grátis — 8 de 45 perguntas. Cadastre-se para ver todas.
  1. 1.Which of the following is NOT one of the three main types of rocks?

    Easy
    • ASedimentary
    • BMetamorphic
    • CIgneous
    • DMinerals
  2. 2.Which type of rock is formed from the cooling and solidification of magma or lava?

    Easy
    • ASedimentary
    • BMetamorphic
    • CIgneous
    • DMinerals
  3. 3.Which of the following processes is responsible for turning sediments into sedimentary rock?

    Easy
    • AMelting and cooling
    • BHeat and pressure
    • CCompaction and cementation
    • DWeathering and erosion
  4. 4.What conditions are necessary for metamorphic rock to form?

    Easy
    • AHigh temperature and pressure
    • BCooling of magma
    • CCompaction of sediments
    • DWeathering and erosion
  5. 5.Which of the following is an example of an igneous rock that forms from lava cooling quickly on the Earth's surface?

    Medium
    • AGranite
    • BBasalt
    • CMarble
    • DSlate
  6. 6.Which rock type is most likely to contain fossils?

    Medium
    • AIgneous
    • BMetamorphic
    • CSedimentary
    • DAll rock types
  7. 7.Magma is molten rock found on the Earth's surface.

    Easy

    True or false?

  8. 8.Match each rock type with its formation process.

    Medium
    • Igneous
    • Sedimentary
    • Metamorphic
    • Cooling of magma
    • Compaction of sediments
    • Heat and pressure

Unlock all 45 questions, flashcards & more

Crie uma conta grátis para ver todas as perguntas, os slides, flashcards e resumos de revisão deste tópico.

Provas anteriores

A prática com provas anteriores deste tópico chega em breve.
Em breve