Merrimack Group  search
BTChronostratigraphic Units
 .Phanerozoic
 ..Paleozoic
 ...Merrimack Group
RTOrdovician
 Silurian
 Massachusetts
 New Hampshire
 Maine
 Berwick Formation
 Kittery Formation
SNSW Maine, NE Massachusetts and SE New Hampshire. Includes Berwick Formation, Kittery Formation. Indexed with ages as applicable. Added to Thesaurus in 1989.