sub-Aftonian
/sʌbafˈtəʊnɪən/Geology. Now rare or disused
adjective
Designating (deposits associated with) a glaciation immediately preceding the Aftonian interglacial in North America; = Nebraskan.
- See note at Aftonian..
Origin
Late 19th century; earliest use found in Journal of Geology. From sub- + Aftonian.