248 A HISTORY OF LONGRIDGE. [Chap. 12, 



many other kindred matters of equal interest are made clear to the 

 student of geology. His tutors are the rocks themselves. 



Within the limits of a chapter it wiU be impossible to give more 

 than a bare outline of the geology of the distiict and of the physical 

 changes that have occurred since the oldest rock was laid down. This, 

 however, will be given in as interesting a manner as the space will 

 admit, in the hope that it will stimulate to further investigation. 



On a geological map of England, Longi-idge is seen to be situate a 

 short distance from the edge of the Lancashire coal-field and on the 

 slope at the extremity of a spur- of the Pennine Range. 



The imderlying rocks are members of the Toredale series, and these, 

 together with aU the solid rocks in the immediate vicinity, are members 

 of the carboniferous system. They do not often appear at the surface, 

 but are mostly obscured from view by a covering, sometimes several 

 feet thick, of boulder-clay, of drift-sands and gravels, or of surface 

 soil, or of two or more of these deposited one above the other. (See 

 plate 1). 



That most important member of the carboniferous system, the Coal 

 Measures, the presence of which would constitute Longridge a place of 

 great commercial importance, is wanting. But so nearly do some of 

 the rocks in the neighbourhood resemble certain beds associated with 

 the coal-measures that in days gone by they were frequently mistaken 

 for them, and the remains of shafts which have been sunk in search of 

 coal may yet be seen in the basins of the Eibble and the Hodder.' 



As all the members of the carboniferous system do not occur in this 

 district, it will be well to give here a table of the complete system with 

 a table of the carboniferous rocks of the district for comparison. 



The following are the principal divisions that have been made in 

 carboniferous rocks :— ■^ThickS" 



in feet. 



! Upper Coal Measures . . 4,000 



Middle , 4,000 



Lower „ „ 2,000 



Millstone Grit 5,000 



1 Yoredale Rocks (Upper Limestone Shale) . . 4,000 



Lower Do. •) Carboniferous Limestone 4,000 



I Lower Limestone Shala 1,500 



I Woodward. in the Chipping district, with, of course. 



About 20 years ago shafts were sunk no success.— iT. C. S.) 



