Siltstones, mudstones and coals are overbank and swamp deposits of the coastal plain.
(Siltstones, mudstones and coals; are; overbank) (Siltstones, mudstones and coals; swamp; deposits of the coastal plain)
Siltstones, mudstones and coals Siltstones, mudstones and coals
are swamp
overbank
deposits of the coastal plain