KomatiiteA3
English:
Photo by user:Rolinator. Taken August 2006. This photo shows typical A3 facies bladed olivine spinifex, Widgiemooltha Komatiite, Widgiemooltha Dome, Western Australia. The sample is from drill core from drillhole WDD18, at approximately 139m downhole. The olivine crystals form sheafs or booklets of plated crystals within glass, which has since been metamorphosed to a chlorite-actinolite-serpentine-magnetite assemblage and sulfidated from magnetite to pyrite. It is rare to see such perfectly preseved spinifex textures within serpentinised ultramafic rocks.
NB: Text on the drill core "UKAH0" is local logging code, U = Ultramafic, K = spinifex textured, A = amphibole, H = chlorite, 0 = undefined. Rolinator 03:34, 21 August 2006 (UTC)Relevante Bilder
Relevante Artikel
KomatiitKomatiite sind ultramafische, aus dem Erdmantel stammende vulkanische Gesteine. Einige Vorkommen werden jedoch auch als intrusive Gesteine angesehen. Als spezielle Gesteinsart wurden sie 1962 erkannt und nach der Typlokalität am Komati River in Südafrika benannt. .. weiterlesen