Gigayear

Holonyms: exasecond < zettasecond < yottasecond < ronnasecond < quettasecond

Meronyms: quectosecond < rontosecond < yoctosecond < zeptosecond < attosecond < femtosecond < picosecond < nanosecond < microsecond < millisecond < centisecond < decisecond < second < decasecond < minute < hectosecond < kilosecond < hour < day < week < megasecond < fortnight < month < year < gigasecond < century < kiloannum, kiloyear, millennium < terasecond < mega-annum, megayear < petasecond

These syntheses gave a fresh geological, as opposed to solely geophysical, view of the up to multi-megayear and near gigayear mechanism responsble for the palimpsests of a general process of change in the upper crust: a process that we may observe, often apparently 'frozen' -- because it is so slow, at different steps in the process, in different places within the upper crust.

The illustrative example here provides for a few gigayear spread in ages of tracers of the stellar halo in a spiral (this is obviously sensitive to the chosen turnaround redshift) as found for the Milky Way field stars (Schuster & Nissen 1989) and globular clusters (reviewed by Bolte 1993).

It's hard to tell the difference between a 5-gigayear, 8-gigayear, and 10-gigayear cluster for such a sparse object as this unless you've got very high-quality photometry.

The fraction could be as high as 100% if the nuclear activity lasts much less than a gigayear.