Topic 1: Rocks and Rock Formation

Comprehensive vocabulary flashcards covering rock types, processes of formation, sedimentary classifications, metamorphism, rock uses, the rock cycle, and fossils.

Igneous Rocks

Rocks formed when molten rock (magma or lava) cools and solidifies, characterized by crystal texture and no fossils.

Sedimentary Rocks

Rocks formed from sediments that are compacted and cemented together, characterized by distinct layers (strata) and commonly containing fossils.

Metamorphic Rocks

Rocks formed when existing rocks are changed in form and structure by heat, pressure, and chemically active fluids without melting.

Magma

Molten rock located underground that cools slowly to form intrusive igneous rocks.

Lava

Molten rock on the Earth's surface that cools quickly to form extrusive igneous rocks.

Weathering

The breakdown of rocks into smaller pieces (sediments) by wind, water, ice, or chemical reactions.

Erosion

The movement of sediments by wind, water, ice, or gravity.

Deposition

The process that occurs when moving water, wind, or ice slows down and drops sediments.

Compaction

The process in sedimentary rock formation where layers of sediment build up, pressure squeezes sediments together, and water is forced out.

Cementation

The process in sedimentary rock formation where minerals dissolved in water fill gaps, acting like glue to turn sediments into solid rock.

Clastic Sedimentary Rocks

Sedimentary rocks made from fragments of other rocks through weathering, erosion, deposition, compaction, and cementation.

Chemical Sedimentary Rocks

Sedimentary rocks formed when minerals precipitate out of water, commonly found in salty lakes and seas.

Organic (Biochemical) Sedimentary Rocks

Sedimentary rocks formed from the remains of living organisms, such as coal and some limestones.

The Law of Superposition

The geological rule stating that each rock layer is older than the layer above it, meaning lower layers are older and upper layers are younger.

Intrusive Igneous Rocks

Igneous rocks that form underground from magma, cooling slowly to develop large crystals (e.g., granite).

Extrusive Igneous Rocks

Igneous rocks that form on the Earth's surface from lava, cooling quickly to develop small crystals (e.g., basalt).

Contact Metamorphism

A type of metamorphism mainly caused by heat that occurs near magma or lava.

Regional Metamorphism

A type of metamorphism caused by both heat and pressure that occurs over large areas underground.

Foliation

A metamorphic rock feature in which minerals line up in layers.

Banding

A metamorphic rock feature characterized by the appearance of different coloured mineral bands.

Metamorphic Progression

The transition sequence of Shale → Slate → Phyllite → Schist → Gneiss, during which increasing metamorphism causes crystals to grow larger and foliation to become more visible.

Granite

An intrusive igneous rock with large crystals that is hard and durable, used for buildings and benchtops.

Marble

A metamorphic rock that is attractive and easy to carve, commonly used for statues.

Slate

A metamorphic rock that splits into flat sheets, commonly used for roof tiles.

Limestone

A sedimentary rock rich in calcium carbonate, commonly used in cement production.

Rock Cycle

The geological cycle following: Igneous Rock → Weathering and Erosion → Sediment → Compaction and Cementation → Sedimentary Rock → Heat and Pressure → Metamorphic Rock → Melting → Magma → Cooling → Igneous Rock.

Fossil

The preserved remains, trace, or impression of an ancient living thing, mostly found in sedimentary rocks.