[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: New Geologic Epoch
> Other proposals to the ICS include mucking about with the
> Carboniferous (again...)
How? Reversing the silly "subera" designation for the Mississippian and the
Pennsylvanian that means the Carboniferous now has 5 epochs consisting of 1
stage each (some of them very long!) and 1 epoch consisting of a whopping 2
> and the Cambrian (again...)
Well, in the Cambrian there isn't a lot to muck about with... 2/3 of the
stages and half of the epochs don't even have accepted names yet...
> and (one I would like to see passed!)
> formal reorganization of a Lower (Berriasian-Aptian), Middle
> (Albian-Turonian), and Upper (Coniacian-Maastrichtian) Cretaceous.
I'd love that, too (and the Permian has already undergone the shift from two
to three subdivisions), except... there's that mass extinction at the
Cenomanian-Turonian boundary, and none at the Turonian-Coniacian one, right?
Could I add changing the Tithonian into the Portlandian, so there can be
an actual type locality?
Body stratotypes are no longer used. Instead, boundary stratotypes are used.
It's a bit like rank-based vs phylogenetic nomenclature, except that the
stratigraphers have (recently) completed the shift. Is the J-K boundary
exposed in Portland?
You are, however, right that the Kimmeridgian-Tithonian and the
Tithonian-Berriasian boundaries don't have stratotypes yet, though the first
has two candidates (http://www.stratigraphy.org/gssp.htm).