Geologic time scale

Geologic time scale

lass="mw-cite-backlink">^ "NASA Scientists React to 400 ppm Carbon Milestone". Retrieved 2014-01-15 [1]
  • ^ a b c d e f Royer, Dana L. (2006). -forced climate thresholds during the Phanerozoic"CO
    2
    " (PDF). Geochimica et Cosmochimica Acta 70 (23): 5665–75.  
  • ^ a b c d e f For more information on this, see Atmosphere of Earth#Evolution of Earth's atmosphere, Carbon dioxide in the Earth's atmosphere, and climate change. Specific graphs of reconstructed CO2 levels over the past ~550, 65, and 5 million years can be seen at Image:Phanerozoic Carbon Dioxide.png, Image:65 Myr Climate Change.png, Image:Five Myr Climate Change.png, respectively.
  • ^ The start time for the Holocene epoch is here given as 11,700 years ago. For further discussion of the dating of this epoch, see Holocene.
  • ^ In North America, the Carboniferous is subdivided into Mississippian and Pennsylvanian Periods.
  • ^ The Precambrian is also known as Cryptozoic.
  • ^ a b c d e f g h i j k l m n The Proterozoic, Archean and Hadean are often collectively referred to as the Precambrian Time or sometimes, also the Cryptozoic.
  • ^ a b c d e f g h i j k l Defined by absolute age (Global Standard Stratigraphic Age).
  • ^ The age of the oldest measurable craton, or continental crust, is dated to 3600–3800 Ma
  • ^ Though commonly used, the Hadean is not a formal eon and no lower bound for the Archean and Eoarchean have been agreed upon. The Hadean has also sometimes been called the Priscoan or the Azoic. Sometimes, the Hadean can be found to be subdivided according to the lunar geologic time scale. These eras include the Cryptic and Basin Groups (which are subdivisions of the Pre-Nectarian era), Nectarian, and Early Imbrian units.
  • ^ a b c d These unit names were taken from the Lunar geologic timescale and refer to geologic events that did not occur on Earth. Their use for Earth geology is unofficial. Note that their start times do not dovetail perfectly with the later, terrestrially defined boundaries.
  • ^ Bowring, Samuel A.; Williams, Ian S. (1999). "Priscoan (4.00–4.03 Ga) orthogneisses from northwestern Canada". Contributions to Mineralogy and Petrology 134 (1): 3.   The oldest rock on Earth is the Acasta Gneiss, and it dates to 4.03 Ga, located in the Northwest Territories of Canada.
  • ^ Geology.wisc.edu
  • ^ a b c d e f g h i j k l m n Van Kranendonk, Martin J. (2012). "16: A Chronostratigraphic Division of the Precambrian: Possibilities and Challenges". In Felix M. Gradstein, James G. Ogg, Mark D. Schmitz and Gabi M. Ogg. The geologic time scale 2012 (1st ed. ed.). Amsterdam: Elsevier. pp. 359–365.  
  • ^ a b c Goldblatt, C.; K. J. Zahnle; N. H. Sleep; E. G. Nisbet (2010). "The Eons of Chaos and Hades". Solid Earth (Copernicus Publications on behalf of the European Geosciences Union) 1: 1–3. 
  • ^ Chambers, John E. (July 2004). "Planetary accretion in the inner Solar System". Earth and Planetary Science Letters 223 (3–4): 241–252.