ON OPPOSITE SIDES OF THE PENNINE CHUN. 185 



of the great anticlinal range, traversed its eastern and western sides 

 on its march from north to south. 



That vast masses of drift deposits overspread the wide plains of 

 Western Lancashire and adjoining counties, extending from the 

 Irish Sea in one unbroken sheet to the slopes of the Pennine Hills, 

 and thence mounting up to higher levels, and penetrating almost 

 every upland valley and mountain-gorge to considerable elevations, 

 is too well known and too generally acknowledged to require any 

 amplification from me on the present occasion. 



A great number of facts, and the statements of various autho- 

 rities as to the altitude of high-level drift on the western slopes 

 of the Pennine chain, indicate a general elevation of from 1100 

 to 1200 feet, whilst scattered boulders and pebbles of travelled rocks 

 may be detected at various places in the locality some 200 feet in 

 excess of that ; and I contend that these more elevated stray boulders 

 and pebbles owed their origin to icebergs during the interglacial 

 period, and not to the period of land ice. 



I wish particularly to direct attention to the circumstance of drift 

 having been found at an elevation of 930 feet above sea-level, on 

 the shoulders of the hills on both sides of the southerly termination 

 of the Walsden defile at the summit near Littleborough, whilst 

 all traces of them vanish in a line almost coincident with the 

 watershed of the valley, which has an elevation of 627 feet, beyond 

 which no accumulations of this character are met with in travelling 

 cast for a distance of about 15 miles. The first indication of their 

 presence as a regular bed of drift occurs in the valley of the Calder at 

 ^sorth Dean, near Halifax, where, in sinking for the foundations of 

 a railway viaduct, the following section was observed by Mr. James 

 Spencer, of Halifax, to whom I am indebted for the accompanying 

 particulars : — 



ft. 



Soil 1 



Fine alluvial sand 8 



Gravel derived from local rocks 2 



Gravel containing granite, trap, slate, and Silurian rocks 3 



Total 14 



It is, however, stated that an occasional pebble foreign to the 

 district has been noticed in the bed of the river Calder, a little 

 further to the west than the spot just named*. 



Close to the railway bridge at Elland, in the bank on the south 

 side of the river Calder, under about 5 feet of sandy loam, a bed of 

 gravel exists, about 4 feet of which is exposed, and which I am 

 informed by Mr. Davis, F.G.S., of Greetland, has been proved by a 

 well-sinking to be from 15 to 20 feet in thickness, in which red 



* Dr. Alexander, in describing the geology of the parish of Halifax, in the 

 • Tracts " of the Geological and Polytechnic Society of the West Riding of 

 Yorkshire, 3rd June, 1841. p. 201, mentions that " in prosecuting the works on 

 the line of railway some blocks of granite had been found near Hebden Bridge;" 

 and Mr. Binney also informs me that he has seen foreign pebbles at Hebden 

 Bridge. 



