craton

Stable lithospheric block

A craton is a stable, ancient portion of continental crust that has remained relatively unchanged for billions of years.

Cratons form the geological cores of continents, resisting the tectonic forces that reshape younger rock: The Canadian Shield is part of the North American craton.

They contain some of Earth's oldest known rocks.

stability

stable

Secure and unchanging

ancientVery old indeed
ArcheanEarliest geological eon
ProterozoicEon before complex life

Precambrian · primordial · enduring · rigid · thick · cold · buoyant · depleted · refractory · undeformed

geology

shield

Handheld defensive armor

basementSubterranean building level
gneissFoliated metamorphic rock
graniteIgneous rock, quartz-rich

Superior · Wyoming · Siberian · Australian · Tanzanian · Amazonian · Congo · Kalahari

tectonic

plate

Flat dish for food

lithosphereCrust plus upper mantle
PangaeaPrehistoric unified landmass
GondwanaAncient southern supercontinent

supercontinent · rifting · subduction · orogeny · terrane · accretion · collision · breakup · assembly · margin

structure

crust

Hard outer layer

isostasyGravitational balance of landmasses
thicknessDepth of material
depthDistance below surface

kimberlite · xenolith

Opposites

crustal stability

cratonsubduction zone

Where one plate slides under another

volcanic arc · collision zone · tectonic boundary · accretionary wedge · mid-ocean ridge

crustal type

cratonoceanic crust

Basaltic layer beneath seas

oceanic plate

Phrases

bomb craterPit from detonation
crater lakeWater in volcanic hollow
smoking crater
volcanic craterDepression from eruption
impact craterMeteorite collision depression
shell craterPit from artillery impact

Family

crater

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