Word Study
neocomian
CIDE DICTIONARY
neocomian, n. [From Neocomium, the Latin name of Neuchatel, in Switzerland, where these rocks occur.].
A term applied to the lowest deposits of the Cretaceous or chalk formation of Europe, being the lower greensand. [1913 Webster]
neocomian, a.
Of or pertaining to the lower greensand. [1913 Webster]
For further exploring for "neocomian" in Webster Dictionary Online