86 J. G. Gf GODCHILD ON THE GLACIAL PHENOMENA OF THE 



came to the conclusion that many of these apparent contortions 

 may he due to the half-consolidated glacial mud slipping downwards 

 to lower levels, and thereby causing a puckering of the beds. In 

 this way certain parts of the clays must often have been thrown 

 into sharp folds, and afterwards covered by laminae that had not 

 participated in the movement ; so that it is easy in such a case 

 as this to account for the occurrence of laminated clays bent 

 into the most fantastic forms, and yet lying between perfectly 

 horizontal layers of the same deposit. When such a series of strata 

 is cut along a face nearly at right angles to the line of highest 

 inclination, we should find the outcrops following sinuous lines 

 which would impart an appearance of contortion to the deposit more 

 or less marked in proportion to the amount of puckering the clays 

 had undergone in slipping down the slope upon which they were 

 deposited. In this way if any of the foldings bulged more in one 

 part than in another, such a section-face as that mentioned above 

 would show rudely ellipsoidal lines of outcrop one within another, 

 in much the same way, to use a homely illustration, as the coatings 

 of an onion appear when a slice is cut off the side of it. Although 

 it is not supposed that this explanation will account for all the 

 contortions in the clayey beds associated with the till, and still less 

 for those in the Boulder-clays of the maritime districts, it will be at 

 least worth while to bear it in mind in examining sections of what 

 appear to be contorted clays elsewhere*. 



The other beds in the cutting do not call for any particular 

 mention, as they contain beds of laminated clays in every way like 

 those just described ; and the whole series, as before remarked, is 

 overlapped by the stratified upper till, without any very clear line 

 of demarcation between. 



The first cutting north from Longwathby is through a tough 

 maroon clay, containing a great variety of boulders up to 4 feet in 

 diameter, including many from Galloway. Most of the stones are 

 more or less waterworn; but the larger boulders retain a few 

 scratches, and a few of the smaller are apparently as little rolled as 

 those in ordinary till. The boulders are scattered throughout the 

 clay without any indication of sorting, and the whole of the matrix 

 shows faint traces of very irregular lamination, which is most evi- 

 dent on the freshly cut banks that have been washed by rain or by 

 runlets of water from the top of the cutting. In this way the 

 tougher laminae are left in relief, and show some remarkable instances 

 of curved lamination, though there is no trace of any thing like con- 

 tortion in the cutting (fig. 8). 



Another section, about a hundred yards or so to the north, shows 

 beds of sand and gravel flanking the clay of the last-mentioned cut- 

 ting, and overlapped by another clayey drift. What principally 

 calls for notice in this section is the occurrence of undoubted in- 

 stances of contortion on a small scale, apparently caused by the 



* Since the above was written I bare stated my belief that these contortions 

 are due, in great part, to the settling-down of the ice-sheet upon half-consoli- 

 dated beds beneath. See ' Geol. Mag.' for Nov. 1874, 



