6 PROFESSOR P. F. KENDALL AND MR E. B. BAILEY 



the hard are very beautiful. The grooves persist in their original direction, but grad- 

 ually rise to surmount the obstruction, and upon the other side sink as gradually to 

 their former level. A small patch of alluvium near Morham Church serves to mark the 

 original presence of a shallow tarn excavated along one of these grooves just east of 

 where the change of slope commences. 



Certain of the grooves south of Haddington have been employed as temporary 

 watercourses at a later period, but the work of the streams which thus made use of 

 them was chiefly the deposition of alluvium upon the broad bottoms of the hollows. 



Elsewhere the sculpturing is not so well developed as in the district just described, 

 but round the termination of the hills it serves to indicate the deflection of the ice 

 current which has already been referred to. 



Let us now return from the consideration of the direct effects of sub-glacial erosion 

 to the correlative phenomenon of deposition. The district furnishes three very fine 

 examples of large transported masses of limestone. The most conspicuous is that of 

 Kidlaw, a mass one-third of a mile long and a quarter broad and well exposed in 

 extensive disused quarries. The view that this great mass might really be a boulder 

 was first suggested some years ago in conversation by Mr Howell, and the evidence 

 for this interpretation is threefold. 



1. The few exposures in the immediate neighbourhood and general considerations 

 as to the geological structure of the district, point to the conclusion that the limestone 

 is resting on sediments of Upper Old Red or early Calciferous Sandstone age, with 

 associated igneous rocks. The limestone, moreover, has been recognised by 

 Dr Crampton as belonging to the middle and not the bottom of the Lower Limestone 

 group of the Scotch Carboniferous sequence. Under these circumstances one has to 

 account for the apparent absence of a great thickness of strata, all included in a 

 conformable sequence and well developed in the near neighbourhood. 



2. The whole mass is in a completely shattered state. Mr Howell * in his 

 original description attributed this feature to the proximity of the Lammermuirs fault. 

 But the longest axis of the " outlier" is directed away from the fault, and it would be 

 very difficult, therefore, to maintain this interpretation ; moreover, since Mr Howell 

 mapped the ground, a large basalt quarry has been opened in the immediate vicinity 

 and equally close to the fault. The basalt sill is there entirely unshattered, though 

 the period of its intrusion certainly greatly antedated the faulting. 



3. There is a great abundance of limestone blocks, both large and small, in the 

 boulder clay of the adjoining areas, whether it rests upon Silurian, Old Red, or 

 Carboniferous strata. 



The second example is recorded by Dr Crampton at Marl Law quarry, a mile N.W. 

 of Fala. It consists of a contorted mass of limestone and marl, lying not very far from 

 the natural outcrop of the group. It may perhaps not be without significance that 

 the Kidlaw and Marl Law masses lie along the same line of glacial transport. 



* Geology of East Lothian, 1866, p. 55. 



