Manchester Memoirs, Vol. Ixii. (1918), No. 11. 15 



Bar, past the junction of Cornbrook Street with Chorlton Road to 

 the east of Oxford Road Station and Manchester Town Hall, 

 across Piccadilly and between Rochdale Road and Oldham Street. 

 Reference to the map will show that there is a hill of some 120 feet in 

 height, forming the western side of this valley. The highest part of 

 this hill runs from just south of Albert Square to the north angle of 

 Central Station, the pre-Glacial surface in general rising from the old 

 valley-bed towards the present channel of the Irwell. On the 

 eastern side of the same ancient valley is a hill of similar height 

 under London Road Station and its neighbourhood, and across this 

 hill the Medlock is now cutting its way, as mentioned by Mr. Charles 

 Roeder in his description of the Oxford Road sewer. 1 



This pre-Glacial vaUey is joined, just to the north of Brook's 

 Bar, by another coming in from the east. This second valley 

 can be traced upwards from the neighbourhood of Brook's Bar 

 to the south of the Royal Eye Hospital and across Plymouth 

 Grove Recreation Ground. It may possibly be connected with one 

 which lies near the Levenshulme Print Works. 



These two pre-Glacial valleys which unite near Brook's Bar 

 presumably open into a deep valley across Trafford Park, the presence 

 of which is certainly indicated by the boring of the British Steel and 

 Wire Company, to which reference has already been made, as well 

 as by the channel exposed at Salford Racecourse in the cutting of the 

 Ship Canal. 2 The information concerning this latter valley is insuffi- 

 cient for mapping it ; it probably ran from north-east to south-west, 

 as on such a line bore-holes give greater depths in the rock surface 

 than those on either side. The present bed of the Irwell is un- 

 related to this deep valley — this is clearly seen in the section, PL III., 

 Fig. 3, which shows the Irwell cutting its valley in the rock which rises 

 steadily to the west of the Brook's Bar and Piccadilly valley as far 

 as the Irwell. The most remarkable feature of this valley is its 

 great depth. At Trafford Park it is 94 feet below O.D. As the fall 

 of the river in pre-Glacial times from this point to its mouth cannot 

 have been much less than it is now, this depth means that there has 

 been an alteration in the height of the surface of about 178 feet 

 since pre-Glacial times. 



A similarly deep valley has been described by Mr. Mellard Reade 3 

 in the neighbourhood of Widnes. Here the valley is 141 feet below 

 O.D. and 163 feet below the surface. Allowing for the fall of the 

 river to be the same from Widnes to the sea in pre-Glacial and present 

 times, these figures give an alteration of 185 feet in level since pre- 

 Glacial days. Another part of this buried valley is described by Mr. 

 Hunter 4 as being 120 feet deep. This is at Latchford, near Warring- 

 ton. Each of these deep channels, at Old Trafford, Latchford and 

 Widnes, lies in the present river valley, but is not coincident with 

 the existing river-bed. 



1 Trans. Mane. Geol. Soc, XX. 



2 Hunter, C. E. Trans. Mane. Geol. Soc, XVII. 



3 Proc. Liv. Geol. Soc, II. 



4 Trans. Mane Geol. Soc, XVII. 



