Abstract
Morphologically diverse microfossils were reported from Archaean (3.0Ga) black chert in the Farrel Quartzite in the Pilbara Craton, Western Australia (Sugitani et al., 2007).In this study, Rare Earth elements and Yttrium concentration were analyzed to understand the origin and depositional environment of the black chert. The fossil-containing black chert occures with evaporites. Other types of black cherts in the same region(chert vein, laminated chert, chert-evaporite association with no microfossil) were also analyzed for comparison. Shale(PAAS)-normalized REE+Y pattern indicates that the fossil-containing black chert was formed in a shallow restricted basin. In addition, no high-T hydrothermal signature was shown.
