SBZ17-18

One of the discussions involved the SBZ17-18 subdivision:

1) delineating the boundary between SBZ17-18

2) subdivision of SBZ18

3) is the extinction of large Nummulites diachronous? And how would this affect the SBZ17-18 boundary?

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith