﻿1851.] BRICKENDEN ON THE BOULDER CLAY NEAR ELGIN. 289 



3. On the Occurrence of the Boulder Clay in the Limestone 

 Quarry, Linksfield, Elgin, N.B.* By Capt. Lambart 

 Brickenden, F.G.S. 



As there has been observed near Elgin, Morayshire, a very singular 

 phenomenon connected with the Boulder-clay Formation, which is 

 seen to occupy a position that could only have been attained under 

 very remarkable circumstances, I think that a communication on the 

 subject may not be devoid of interest to some of the members of the 

 Geological Society. The rock which prevails around Elgin is re- 

 ferred to the Upper Division of the Devonian system ; and at Links- 

 field, which is a farm north of the town, the superior beds of that 

 formation appear in the character of a limestone, which is very ex- 

 tensively quarried for agricultural purposes. In order, however, to 

 raise the limestone, it is necessary to remove an overlying formation, 

 about 40 feet deep, composed of a series of Oolitic beds, in them- 

 selves of great geological interest. Now it is between the limestone 

 of the Devonian system and the strata of the Oolite that the phseno- 

 menon exists which is the subject of this notice, — being an extensive 

 intercalation of Boulder-clay, which since the opening of the quarry 

 has been penetrated beneath the incumbent horizontal beds, to the 

 extent of 120 yards, with no appearance whatever of its termination ; 

 and this distance is measured in a direction at right angles to the 

 course pursued in its excavation ; whilst in a transverse line or sec- 

 tion of the quarry, the intercalated mass has been observed to extend 

 nearly 300 yards. The surface of the clay is very irregular and un- 

 even, and its thickness varies from 2 to 4 feet ; and I am assured by 

 an intelligent old man, who has visited the quarry very constantly 

 since it was first opened about thirty years ago, that at the distance 

 of more than 100 yards from where it now is the clay was observed 

 to be about the same depth, and overlaid, as now, by the same series 

 of Oolitic strata in their undisturbed position. On the north-western 

 boundary of the quarry the thickness of the intercalation increases 

 considerably, and there can be little doubt that in this direction the 

 clay obtained an entrance. 



That the drift, thus alluded to, has been forced into the place it now 

 occupies is the opinion generally entertained by those who have ex- 

 amined it ; and this appears to be fully sustained by certain peculi- 

 arities which the bed discloses, although it is not very easy to con- 

 ceive the exact manner in which such an extensive and marvellous 

 intrusion was effected. The surface of the Boulder-clay, and also of 

 the strata between which it has been propelled, is hardened, abraded, 

 and marked with polished strise, indicating the direction in which the 

 mass has moved, which is nearly from north-west to south-east, or in 

 a line at right angles to the natural escarpment of the hill and out- 

 crop of the strata. The clay, moreover, contains the debris of the 

 upper as well as of the lower formation, and it is identical in colour 



* This communication was a sequel to a paper on the same subject read before 

 the Society November 20, 1850, and withdrawn by the Author. Both communi- 

 cations are now printed together. 



VOL. VII. — PART I. X 



