Hadajk

Hadajk je Zemljin geološki eon koji datira iz perioda pre Arhaika. Počeo je formiranjem Zemlje pre oko 4,6 milijardi godina i završio se, kako je definisala Međunarodna komisija za stratigrafiju (ICS), pre 4 milijarde godina.^[1] Status Hadajka je prema oceni ICS neformalan.^[2] Ime mu je dao geolog Preston Klaud 1972, da bi označio period pre najstarijih poznatih stena.^[3]^[4]

Pošto postoji malo tragova o Hadajku na Zemlji, za sada nemamo podelu na niže kategorije.

U poslednjim decenijama 20. veka geolozi su identifikovali nekoliko stena iz Hadajka na području zapadnog Grenlanda.^[5]^[6]

Reference[uredi | uredi izvor]

^ „International Chronostratigraphic Chart 2015” (PDF). International Commission on Stratigraphy. Pristupljeno 23. 1. 2016.
^ Ogg, J. G.; Ogg, G.; Gradstein, F. M. (2016). A Concise Geologic Time Scale: 2016. Elsevier. str. 20. ISBN 978-0-444-63771-0.
^ Cloud, Preston (1972). „A working model of the primitive Earth”. American Journal of Science. 272 (6): 537—548. Bibcode:1972AmJS..272..537C. doi:10.2475/ajs.272.6.537.
^ Bleeker, W. (2004). „10. Toward a "natural" Precambrian time scale”. Ur.: Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. A Geologic Time Scale 2004. Cambridge, England, UK: Cambridge University Press. str. 145.
^ Borenstein, Seth (19. 10. 2015). „Hints of life on what was thought to be desolate early Earth”. Excite. Yonkers, NY: Mindspark Interactive Network. Associated Press. Pristupljeno 20. 10. 2015.
^ Bell, Elizabeth A.; Boehnike, Patrick; Harrison, T. Mark; et al. (19. 10. 2015). „Potentially biogenic carbon preserved in a 4.1 billion-year-old zircon” (PDF). Proc. Natl. Acad. Sci. U.S.A. Washington, D.C.: National Academy of Sciences. 112: 14518—21. Bibcode:2015PNAS..11214518B. ISSN 1091-6490. PMC 4664351 . PMID 26483481. doi:10.1073/pnas.1517557112. Архивирано из оригинала (PDF) 06. 11. 2015. г. Приступљено 20. 10. 2015. Early edition, published online before print.

Hopkins, Michelle; Harrison, T. Mark; Manning, Craig E. (2008), „Low heat flow inferred from >4 Gyr zircons suggests Hadean plate boundary interactions”, Nature, 456 (7221): 493—496, Bibcode:2008Natur.456..493H, PMID 19037314, doi:10.1038/nature07465 .
Valley, John W.; Peck, William H.; King, Elizabeth M. (1999), „Zircons Are Forever”, The Outcrop for 1999, University of Wisconsin-Madison, Архивирано из оригинала 16. 03. 2012. г., Приступљено 10. 1. 2006 – Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago.
Wilde, S. A.; Valley, J. W.; Peck, W. H. & Graham, C. M. (2001), „Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago”, Nature, 409 (6817): 175—178, PMID 11196637, doi:10.1038/35051550 .
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Carley, Tamara L.; et al. (2014), „Iceland is not a magmatic analog for the Hadean: Evidence from the zircon record”, Earth and Planetary Science Letters, 405 (1): 85—97, Bibcode:2014E&PSL.405...85C, doi:10.1016/j.epsl.2014.08.015 .