The interval definitions in this timescale are derived from the following source:

• W. B. Harland, R. L. Armstrong, A. V. Cox, L. E. Craig, A. G. Smith and D. G. Smith. 1990. A Geologic Time Scale 1989. view

There are 1 timescales which overlap this one. show

• Obsolete Precambrian Ages

This timescale is used in the definition of 6 collections