Cyclostratigraphy

The nature of sediments can vary in a cyclic fashion, and these cycles can be displayed in the sedimentary record - here visible in the colouration and resistance of strata

Cyclostratigraphy is the study of astronomically forced climate cycles within sedimentary successions.[1] Astronomical cycles are variations of the Earth's orbit around the sun due to the gravitational interaction with other masses within the solar system. Due to this cyclicity solar irradiation differs through time on different hemispheres and seasonality is affected. These insolation variations have influence on earth's climate and so on the deposition of sedimentary rocks.

The main orbital cycles are precession with at present main periods of 19 and 23 kyr, obliquity with at present main periods of 41 kyr, and 1.2 Myr, and eccentricity with at present main periods of around 100 kyr, 405 kyr, and 2.4 Myr.[2]

Cyclostratigraphic study of rock records can lead to accurate dating of events in the geological past, to increase understanding of cause and consequences of earth's (climate) history, and to more control on depositional mechanisms of sediments and the acting of sedimentary systems.

See also

References

  1. ↑ Andre Strasser, Frederik Hilgen, Philip H. Heckel. "Cyclostratigraphy - from orbital cycles to geologic time scale". 2008. http://www.cprm.gov.br/33IGC/1312131.html
  2. ↑ Hinnov L.A. & Ogg J.G. (2007). "Cyclostratigraphy and the Astronomical Time Scale" (PDF). Stratigraphy 4 (2-3): 239–251.
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