Continental crust

Continental crust is Earth’s thick, relatively low-density outer rock layer beneath continents and their submerged margins. It is compositionally diverse and generally much older than oceanic crust.

Earth's crust: Earth’s crust is the planet’s outermost solid layer, composed of continental and oceanic domains. Continental crust is one of the two major types of Earth’s crust.
Continental crust formation: Continental crust formation is the set of geological processes that creates new continental material from mantle-derived rocks. It describes how continental crust originates rather than merely how it is classified.
Oceanic crust: Oceanic crust is the relatively thin, dense crust underlying ocean basins, formed mainly at mid-ocean ridges. Its typical basaltic composition and rapid recycling contrast with continental crust.
Canadian Shield: The Canadian Shield is a vast region of exposed Precambrian crystalline basement in central and eastern Canada. Its exposed ancient rocks reveal some of the oldest surviving continental crust.
Hadean Earth: The Hadean is the earliest interval of Earth’s history, before the oldest widely accepted rocks in the geological record. The scarcity of preserved rocks makes the onset of continental crust difficult to reconstruct.
Continental lithosphere: Continental lithosphere comprises continental crust and the rigid uppermost mantle beneath it. The crust’s mechanical behavior depends on its coupling to this underlying rigid layer.
Subduction: Subduction is the descent of one tectonic plate beneath another into the mantle. Water and melting above subducting plates generate magmas that contribute to continental growth.
Mid-ocean ridge: A mid-ocean ridge is a seafloor mountain chain where tectonic plates diverge and new oceanic crust forms. New crust is continuously produced here, unlike the long-lived continental record.
Pilbara Craton: The Pilbara Craton is an ancient block of continental crust in Western Australia, containing rocks more than three billion years old. Its rocks preserve evidence about early continental crust and Archean environments.
Jack Hills zircon: Jack Hills zircons are ancient mineral grains from Western Australia, some dating to about 4.4 billion years ago. Their chemistry offers indirect clues to crustal conditions before surviving continental rocks formed.

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