Arie and John,

Re: Having Pb refer to a "basaltic" layer as Pg refers to a 
"granitic" crustal layer:

That seems to be the answer, and why most continental seismologists
have not seen it because they (we) have generally not had a "basaltic" 
layer to work with. And taking it further, a "Ps" phase for a 
sedimentary surface layer wouldn't work either, since "S" is taken for 
shear wave propagation, hence the wildcard notation "P*", which would 
(of course) also cover all surface layer geologies above the Conrad
discontinuity.

Regards, 
Sean-Thomas
__________________________________________________________

Public Seismic Network Mailing List (PSN-L)