Factors which affect the age estimate

1 Present day effective temperature of the site

Age estimates for the UK assume a present day effective temperature (T_eff) of 10.0°C.  If this site is older or water than this the age estimate will be over- or under-estimated respectively.  Samples lying close to the surface may experience seasonal temperature fluctuations which will increase the T_eff.

2. Past climate changes

Most users find an age estimate helpful. This age estimate is only as good as the estimates of the kinetics of racemization and the past temperature of the site. The former can be derived from laboratory studies and verified using fossils of know age and temperature history.  The past temperature of the site is a real challenge.  The current estimated temperature history used to derive age estimates is shown (right). 

Estimated southern England temperature profile used to derive "ages"