harlech group

from The Collaborative International Dictionary of English v.0.48

Harlech group \Har"lech group`\ (h[aum]r"l[e^]k gr[=oo]p`). [So
   called from Harlech in Wales.] (Geol.)
   A minor subdivision at the base of the Cambrian system in
   Wales.
   [1913 Webster]