Details

Autor(en) / Beteiligte

• Puchtel, Igor S.
• Arndt, Nicholas T.

Titel

Archean to recent komatiites and basalts

Ist Teil von

• Reference Module in Earth Systems and Environmental Sciences, 2013

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2013

Link zum Volltext

Beschreibungen/Notizen

• Komatiites, the hottest known magmas, were abundant in the Archean and rare thereafter. They commonly erupted as lava flows with characteristic spinifex texture. Al-depleted komatiites with low Al2O3/TiO2 and Gd/Yb formed at depths >300km. Al-undepleted komatiites with near-chondritic Al2O3/TiO2 and Gd/Yb formed at shallower depths via a fractional melting process. High MgO contents and high inferred potential temperatures indicate that both types formed in hot mantle plumes. Their isotopic compositions point to variably depleted mantle sources. Spatially associated komatiitic and tholeiitic basalts erupted in analogs of recent oceanic plateaus, while calc-alkaline basalts were generated at Archean convergent margins.