Warrawoona Group

Schopf JW, Packer BM (1987) Early Archean (3.3-billion to 3.5-billion-year-old) microorganisms from the Warrawoona Group, Australia. Science 237 70-73... 

Coonteninah and Warrawoona Groups Pilbara Craton, Austraha 3.5 Green et al. (2000)... 

Some of the oldest preserved oceanic plateau sequences are those found in —3.5 Ga Barberton and Pietersberg belts of the Kaapvaal Shield of southern Africa (De Wit et aL, 1987 Smith and Erlank, 1982). These belts contain pillow basalts and komatiites, with chemical signatures (Lahaye et aL, 1995) suggesting a likely origin as part of an oceanic plateau. The Pilbara craton of Australia appears to possess some of the oldest oceanic plateau material so far identified (Green et aL, 2000) in the —3.5 Ga Coonterunah and Warrawoona Groups. 

Green M. G., Sylvester P. I., and Buick R. (2000) Growth and recycling of early Archaean continental crust geochemical evidence from the Coonterunah and Warrawoona Groups, Pilbara Craton, Australia. Tectonophysics 322, 69-88. 

Sulfur on the early Earth has been studied, because it gives insight into the oxidation state of the early atmosphere ocean system (Canfield and Raiswell, 1999). The occurrence of evaporitic sulfate from the 3.5 Ga as in the Warrawoona Group of Western Australia suggests that sulfate must have been present in elevated concentrations at least at some sites. Although now present as barite, the original precipitation occurred... 

Bolhar, R., van Kranendonk, M.J., and Kamber, B.S., 2005b. A trace element study of siderite-jasper banded iron formation in the 3.45 Warrawoona Group, Pilbara Craton - formation from hydrothermal fluids and shallow seawater. Precambrian Res., 137, 93-114. 

Ga (Schopf 1992), but these early Archean occurrences are controversial (Buick 1991). Conical and branched pseudocolumnar stromatolites occurring in 3.46 Ga carbonates and silicified carbonates of the Warrawoona Group, Western Australia were recently described (Hofman et al. 1999). Hoffman et al. concluded that microorganisms were indeed involved in the accretion of these stromatolites. They also surmised that microbial phototaxis might have played a role in shaping them, but concluded that such evidence for the role of photosynthetic biota is not yet definitive. 

Hofman HJ, Grey K, Hickman AH, Thorpe RI (1999) Origin of 3.45 Ga coniform stromatolites in Warrawoona Group, Western Australia. Geol Soc Am Bull 111 1256-1262 Holland HD (1984) The Chemical Evolution of the Atmosphere and Oceans. Princeton University Press, Princeton, NJ... 

Buick R. Dunlop J.S.R. 1990 - Evaporitic sediments of early Archaean age from the Warrawoona Group, North Pole, Western Australia. Sedimentology, 37 247-277. 

---