Landscapes and Rocks Flashcards

Flashcards on Landscapes and Rocks from Leaving Certificate Geography notes.

Rock Cycle

The earth’s natural processes that cause igneous, sedimentary and metamorphic rocks to be formed, changed, destroyed and recycled.

Lithification

Sediments are compacted and cemented together to form solid rock.

Compaction

Sediments are squeezed together by the weight of overlying layers, including water.

Cementation

Water evaporates from dissolved minerals, creating crystals that glue sediments together.

Igneous Rocks

Rocks formed from magma or lava cooling and solidifying.

Sedimentary Rocks

Rocks formed from the accumulation and lithification of sediments.

Metamorphic Rocks

Rocks formed when existing rocks are changed by heat, pressure or chemical processes.

Plutonic Rocks

Igneous rocks formed deep beneath the earth’s surface (intrusive).

Volcanic Rocks

Igneous rocks formed on or near the earth’s surface (extrusive).

Basalt

A dark-colored, fine-grained, volcanic (extrusive) igneous rock.

Granite

A coarse-grained, intrusive igneous rock with visible crystals of quartz, feldspar, and mica.

Sedimentary Rocks

Rocks formed from the accumulation and lithification of sediments.

Organic Sedimentary Rocks

Sedimentary rocks formed from once-living things or decayed vegetation.

Inorganic Sedimentary Rocks

Sedimentary rocks formed from the broken-down sediments of other rocks.

Limestone

A sedimentary rock composed primarily of calcium carbonate (CaCO3).

Sandstone

A sedimentary rock composed mainly of sand-sized mineral particles or rock fragments.

Shale

A fine-grained, sedimentary rock formed from the lithification of mud and clay.

Metamorphic Rocks

Rocks formed when existing rocks are changed by heat, pressure or chemical processes.

Regional Metamorphism

Metamorphism affecting rocks over an extensive area as a result of the large-scale action of heat and pressure.

Contact Metamorphism

Metamorphism due to local heating of rock by an igneous intrusion.

Marble

A metamorphic rock formed from the metamorphism of limestone or dolomite.

Quartzite

A metamorphic rock formed from the metamorphism of sandstone.

Active Plate Margin

A plate margin where tectonic plates collide, resulting in igneous and metamorphic rock formation.

Passive Plate Margin

A plate margin located in the interior of a continental plate, away from crustal boundaries, where sedimentary rocks are typically found.

Quarrying

The extraction of rock from the earth’s surface for building materials and aggregates.

Dimension Stone

Rock that is used in wall covering, sills, curbing, or flagstone.

Aggregates

Sand, gravel, and crushed stone that are quarried for the construction industry.

Plug and Feather

A wedging method used in quarrying to split rocks, using a metal wedge and two shims inserted into pre-drilled holes.