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EXPLANATION OF PLATE IX. 



Map of the Wear, ' Wash,' and Tyne pre-Glacial valleys, on the scale of 

 4 miles to the inch. 



The principal borings, giving the height of the rock-snrface above, or its depth 

 below, sea-level, are shown ; the parts of the country where the rock comes 

 to the surface are shaded, the other parts (left blank) are covered by superficial 

 deposits. 



A = Height of the rock-surface on the higher ground, as obtained from the 

 Ordnance-Survey maps. 



The names of the principal pre-Glacial valleys are marked by inverted 

 commas, and the arrows indicate the direction of these valleys. The map also 

 shows the post-Glacial course of the Wear from Durham to the sea. The 

 country lying east of the Permian escarpment slopes gently eastward, and was 

 denuded by a series of eastward-flowing streams before Glacial times, the 

 present streams being superimposed upon the old watercourses. 



The position of the raised beach on Fulwell and Cleadon Hills is shown, 

 and its exposure along the coast is also indicated. 



Discussion. 



The President, while not venturing to discuss the theoretical 

 questions dealt with hy the Author, said that he was glad to welcome 

 a collection of facts of great interest, namely, the scattered records 

 of deep borings in Drift-accumulations. 



Capt. A. K. Dweeryhouse said that he had listened to the paper 

 with considerable interest, and congratulated the Author upon the 

 admirable and important work which he had accomplished. The 

 pre-Glacial valleys which he had described were particularly inter- 

 esting to the speaker, on account of their similarity to certain 

 valleys in Yorkshire. In the southern portion of Yorkshire there 

 were two types of pre-Glacial valleys running below sea-level, 

 namely : the one, gorge-like valleys, such as that at Barnby Dun 

 (near Doncaster), in which the rock-surface was reached at 170 feet 



