Cyclostratigraphy is the study of astronomically

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 forced climate cycle

Climate cycle

A climate cycle is a type of recurring climate pattern that involves natural cyclic variations in the Earth's surface temperature, as indicated by temperature proxies found in glacier ice, sea bed sediment, tree ring studies or otherwise....

s within sedimentary successions 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

Precession

Precession is a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle is constant...

 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

Orbital eccentricity

The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...

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.