MAPPING OF MILLSTONE GRIT AT LONG ASHTON. 165 
are displayed in the cricket-field section at a, and say 21 feet at 
h ; this lea ves 33 feet in which the Upper Limestone Shales may 
shade into the overlying Millstone Grit. 
At the point marked d in the map grit is exposed in the 
banks of the lane. 
In considering the 'map it must he remembered that the firm 
line marks the axis of the ridge, from which the ground dips 
somewhat steeply in all directions. The marked south-west 
expansion of the area of the Upper Limestone Shales under 
consideration (i. e., between the dotted line of the sandstone 
band and the area of the Millstone Grit) is due to the fact that 
the beds here are dipping with the hill. 
