The Zonation of the Yorkshire Jurassic Flora

Abstract

There has been no recent attempt tozone the great flora of the Bathonian and Bajocian of Yorkshire. The plant-bearing rocks are divided into four, and after investigation of new localities it has been found that there is little zonation, but floral changes do occur. The lowest and highest zones are characterized by the relative abundance of one group of species; the two middle zones are characterized by the relative abundance of another group. There is thus a fluctuation and return in the flora.