Vol. 67.] PERMIAN TO THE TRIAS IN NOTTINGHAMSHIRE. 117 



EXPLANATION OF PLATE V. 



Map of the Permian and Trias of the North-East of England, 

 on the scale of 10 miles to the inch. 



Discussion. 



Prof. Boyd Dawkins said that lie had studied the district chiefly 

 from the point of view of water-supply. He referred to a series 

 of borings which proved the singularly persistent eastward thickening 

 of the Permian marls. A revision of the geological survey had 

 been needed for many years, and he was glad that it was in such 

 competent hands as those of the Author. 



The Author, in reply, said that the information obtained from a 

 number of deep borings to the east of the Permian outcrop was 

 summarized in the paper. The sections showed a thickening of the 

 Permian rocks eastwards and the passage of the Lower Magnesian 

 Limestone into grey mudstones and shales, indicating deeper water 

 towards the east. 



