Start Us marine dating site

Us marine dating site

For relatively recent periods data from radiocarbon dating and dendrochronology also support the MIS data.

The following are the start dates of the most recent MIS, in kya (thousands of years ago).

The first figures are derived by Aitken & Stokes from Bassinot et al.

The MIS data also matches the astronomical data of Milankovitch cycles of orbital forcing or the effects of variations in insolation caused by cyclical slight changes in the tilt of the earth's axis of rotation – the "orbital theory".

Indeed, that the MIS data matched Milankovich's theory, which he formed during World War I, so well was a key factor in the theory gaining general acceptance, despite some remaining problems at certain points, notably the so-called 100,000-year problem.

The MIS timescale was developed from the pioneering work of Cesare Emiliani in the 1950s, and is now widely used in archaeology and other fields to express dating in the Quaternary period (the last 2.6 million years), as well as providing the fullest and best data for that period for paleoclimatology or the study of the early climate of the Earth, Emiliani's work in turn depended on Harold Urey's prediction in a paper of 1947 that the ratio between oxygen-18 and oxygen-16 isotopes in calcite, the main chemical component of the shells and other hard parts of a wide range of marine organisms, should vary depending on the prevailing water temperature in which the calcite was formed.

Over 100 stages have been identified, going currently back some 6 million years, and the scale may in future reach back up to 15 mya.

For older core samples, individual annual depositions cannot usually be distinguished, and dating is taken from the geomagnetic information in the cores.