CERTAIN RIVER-VALLEYS IN LINCOLNSHIRE. 607 



Ancient Gravels of the Trent. — The width of the valley within 

 which the Trent flows from Nottingham to Newark is remarkably 

 even and uniform, the gravels and alluvium taken together forming a 

 long straight tract with a breadth of from 1 J to 2 miles. Throughout 

 this portion of its valley the river has a tendency to impinge upon 

 its right bank, so that the higher and older gravels occur chiefly 

 along the north-western side of the valley, and appear to lie 

 entirely within the bounding slope of the valley on that side. By 

 the Lowdham and Thurgarton stations on the Nottingham and 

 Lincoln railway these gravels form a continuous terrace, which 

 slopes gently down to the modern alluvium of the Trent. 



Near Newark, however, the relations between the older gravels 

 and the modern valleys begin to change; they are found on the 

 eastern bank and stretch away from the river south of Newark and 

 Beacon Hill, forming a continuous tract of gravel-covered country, 

 which extends in a north-easterly direction between the modern 

 valleys of the Trent and Witham. From Coddington, near Newark, 

 the tract passes by Stapleford and Thurlby Moors to Swinderby, and 

 thence it is continued on either side of the Midland Railway as far 

 as Boultham near Lincoln, and only a mile from the entrance to the 

 transverse valley through the Oolitic escarpment. 



To Mr. Penning, who began to map these gravels from the 

 Lincoln end in 1878, belongs the credit of suggesting that they 

 represent the ancient course of the Trent ; and he would doubtless 

 have brought the subject before the notice of the Society, had not 

 ill health obliged him to leave England and afterwards to resign 

 his post on the Geological Survey. 



It is also interesting to note that the Trent was joined by a 

 powerful tributary from the south just before it reached the Oolitic 

 escarpment. The proof of this statement is to be found in a clearly 

 defined tract of gravel which stretches for many miles over the Lias 

 plain below the Oolitic escarpment. This stream appears to have 

 had its source among the hills near Belvoir Castle, where the small 

 river Devon now rises ; we may therefore consider this as the 

 course of the ancient" Devon, which then ran northward to join the 

 Trent, just as the modern Brant joins the Witham near Aubourn. 

 The Brant, indeed, may be regarded as the attenuated represen- 

 tative of this ancient Devon. 



This line of gravel is traversed by the modern channel of the 

 Witham between Hougham and Westborough, about six miles N."W. 

 of Grantham, but continues northward along the ground between 

 the present valleys of the Witham and the Brant as far as Aubourn, 

 where it is again cut through by the Witham. Small patches, how- 

 ever, still remain near South Hykeham, on the northern side of the 

 Witham valley, and lead on to the wide spread of sand and gravel 

 by North Hykeham and Boultham, already mentioned as part of the 

 Trent gravels. 



This long tract of river-gravel is in every respect comparable to 

 those which I have elsewhere described as existing in Cambridge- 

 shire, and which so clearly connect themselves with the ancient 



