'Medina epoch' definitions:

Definition of 'Medina epoch'

From: GCIDE

Medina epoch \Me*di"na ep"och\ [From Medina in New York.] (Geol.) A subdivision of the Niagara period in the American upper Silurian, characterized by the formations known as the Oneida conglomerate, and the Medina sandstone. See the Chart of Geology. [1913 Webster]