Physical Sciences and Mathematics Commons^™

Komatiites Of The Weltevreden Formation, Barberton Greenstone Belt, South Africa: Implications For The Chemistry And Temperature Of The Archean Mantle, Keena Kareem

LSU Doctoral Dissertations

The komatiites of the 3.29 Ga Weltevreden Formation, Barberton Greenstone Belt, South Africa represent extremely magnesian lavas derived from the Archean mantle. Three related papers are presented on aspects of the temperature and composition of the Archean mantle, and surface alteration processes. Petrographical and geochemical analyses confirm that olivines from the komatiites retain much of their original igneous character, containing fresh olivines, pyroxenes, and chromites. The olivines from the Weltevreden Formation are extremely magnesian, with Fo contents up to 95.6. Primitive mantle normalized Gd/Yb values near 1, and Al₂O₃/TiO₃ values of 26-33 for these rocks …