Warrawoona Group

Last updated

Warrawoona Group
Stratigraphic range: Paleoarchean
~3465 Ma
Warrawoona geology 2.JPG
Warrawoona and Western Australia showing geological classification
Type Geological group
Unit of Pilbara Supergroup
Lithology
Primary Chert
Other Archean felsic volcanic rocks
Location
Coordinates 21°42′S118°0′E / 21.700°S 118.000°E / -21.700; 118.000 (Warrawoona)
Region Western Australia
Country Australia
Extent Pilbara craton
Type section
Named for Warrawoona
Named by Arthur Hugh Hickman
Year defined1983
Australia relief map.jpg
Pink ff0080 pog.svg
Warrawoona Group (Australia)
Australia Western Australia relief location map.jpg
Pink ff0080 pog.svg
Warrawoona Group (Western Australia)

The Warrawoona Group is a geological unit in Western Australia containing putative fossils of cyanobacteria cells. Dated 3.465 Ga, these microstructures, found in Archean chert, are considered to be the oldest known geological record of life on Earth. [1] [2] [3]

Contents

Description

The fossils in this group were discovered by Arthur Hugh Hickman in 1983 in Warrawoona, 21°42′S118°0′E / 21.700°S 118.000°E / -21.700; 118.000 (Warrawoona) , a region on the Pilbara craton in the northern part of Pilbara province.

Whether or not the fossils were authentic was disputed in the past, as abiotic processes could not be ruled out. [4] [5] Currently the fossils are thought to be of biological origin, however there is no conclusive evidence of fossilized organisms in the formation, and whether the lines in the rock are fossilized stromatolites. [6]

The rocks also include felsic volcanic rocks. [7]

See also

References

  1. ↑ Skrzypczak, A.; Derenne, S.; Robert, F.; Binet, L.; Gourier, D.; Rouzard, J.-N.; Clinard, C. (March 2004). Characterization Of The Organic Matter In An Archean Chert (Warrawoona, Australia) (PDF). 35th Lunar and Planetary Science Conference. League City, TX. Bibcode:2004LPI....35.1241S.
  2. ↑ Derenne, S.; Robert, F.; Skrzypczak-Bonduelle, A.; Gourier, D.; Binet, L.; Rouzaud, J.-N. (July 2008). "Molecular evidence for life in the 3.5 billion year old Warrawoona chert". Earth and Planetary Science Letters. 272 (1–2): 476–480. Bibcode:2008E&PSL.272..476D. doi:10.1016/j.epsl.2008.05.014.
  3. ↑ Schopf, J. W.; Packer, B. M. (September 1986). "Newly discovered early Archean (3.4–3.5 Ga Old) microorganisms from the Warrawoona Group of Western Australia". Origins of Life and Evolution of the Biosphere. 16 (3–4): 339–340. Bibcode:1986OrLi...16..339S. doi:10.1007/BF02422059. S2CID   39363922.
  4. ↑ Brasier, M. D.; Green, O. R.; Jephcoat, A. P.; Kleppe, A. K.; Van Kranendonk, M. J.; Lindsay, J. F.; Steele, A.; Grassineau, N. V. (March 2002). "Questioning the evidence for Earth's oldest fossils". Nature. 416 (6876): 76–81. Bibcode:2002Natur.416...76B. doi:10.1038/416076a. PMID   11882895. S2CID   819491.
  5. ↑ Hofmann, H. J. (June 2004). "Archean Microfossils and Abiomorphs". Astrobiology. 4 (2): 135–136. Bibcode:2004AsBio...4..135H. doi:10.1089/153110704323175115. PMID   15253835.
  6. ↑ Wacey, D.; Kilburn, M. R.; Saunders, M.; Cliff, J.; Brasier, M. D. (August 2011). "Microfossils of sulphur-metabolizing cells in 3.4-billion-year-old rocks of Western Australia". Nature Geoscience. 4 (10): 698–702. Bibcode:2011NatGe...4..698W. doi:10.1038/ngeo1238.
  7. ↑ DiMarco, Michael J.; Lowe, Donald R. (August 1989). "Stratigraphy and sedimentology of an early Archean felsic volcanic sequence, eastern Pilbara Block, Western Australia, with special reference to the Duffer Formation and implications for crustal evolution". Precambrian Research. 44 (2): 147–169. Bibcode:1989PreR...44..147D. doi:10.1016/0301-9268(89)90080-6.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.