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Cyclostratigraphy is the study of astronomically forced climate cycles within sedimentary successions.〔Andre Strasser, Frederik Hilgen, Philip H. Heckel. "Cyclostratigraphy - from orbital cycles to geologic time scale". 2008. http://www.cprm.gov.br/33IGC/1312131.html〕 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. 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== * Cyclic sediments * Milankovitch cycles * Stratigraphy 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyclostratigraphy」の詳細全文を読む スポンサード リンク
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