210 Dr Hibbert on the Dispersion of Stony Fragments, 



from the Continent, but from the rocks of our own island. 

 This deposit, which consists of a thick continuous bed of clay, 

 very tough, and of a reddish or yellowish brown colour, is to 

 be seen on the north of the town of Manchester, near Strange- 

 ways Hall, an ancient family seat of Lord Ducie. It stretches 

 in a direction from north to south, being interrupted by the 

 cliffs of the newer red sandstone formation which are exposed 

 at the confluence of the rivers Irk and Irwell. How far from 

 this point the bed extends, I am unable to state, but am in- 

 clined to think it must be considerable, since I have observed 

 the same kind of stony fragments, which are to be found in 

 the loam of Strangeways, employed for several miles north in 

 repairing the highways. I am equally unable to assign any 

 limits to the breadth and thickness of this deposit, which are 

 various. As the clay near Strangeways is now in the progress 

 of being cut away for the purpose of brick-making, as well as 

 of widening a road, sections are observable in it to the height 

 perhaps of thirty feet, or more. But this is very far short of 

 its real thickness. The principal circumstance relative to it 

 deserving attention is, that innumerable fragments of rocks, 

 some of which seem of several tons weight, are constantly de- 

 tached from it by the labourers ; and that, while the rocks of 

 this part of Lancashire consist of the newer red sandstone, or 

 of the red marl of geologists, many of the fragments included 

 in the loam are of a much older date, since they belong to the 

 primitive or transition class of formations, and have been evi- 

 dently transported from a considerable distance. Granite, a 

 stranger to the rocks of this district, is abundantly interspersed 

 through the loam, most of the specimens of it containing horn- 

 blende in greater or less quantity. Several varieties of trap- 

 rock, particularly of greenstone, equally unknown in situ, are 

 no less common. Other loosened relics of the hills, of far re- 

 moter districts, possess a stratified structure, and consist chief- 

 ly of the rock named by most geologists grauwacke-slate, but 

 by Dr Macculloch, with far greater propriety, argillaceous 

 schist. It has a basis of clay- slate, with much quartz, dissemi- 

 nated through it in the form of granular particles. Some 

 fragments of this rock have a decidedly conglomerate struc- 

 ture, containing numerous attrited nodules of granite. An- 

 other variety of stony materials found in the loam may be 



