162 



MESSRS. KIRKBY AND DUFF ON THE 



The sandstone contains casts of large Sigillarice and some Cala- 

 mites, and in some curious masses of shale that are included in 

 the sandstone the remains of ferns and other plants. 



These fragments of shale are not regularly intercalated with 

 the sandstone, but strewn broadcast, as it were, like boulders in 

 drift clay. The following woodcuts will give the best idea of 

 their mode of occurrence. 



— - ' "8 Eeet — 



Fig. 4. — Sandstone with enclosed fragments of shale, Brussleton Quarry. 



The pieces of shale are of various tints — grey, greenish, dark 

 blue, and purple : some are finely laminated, and, as just stated, 

 fossiliferous. These stratification planes usually approach those 

 of the sandstone, but in some instances they form a considerable 

 angle to the latter. They show no traces of rounding at the 

 edges as though they had been transported any distance in water. 



Fig. 5. 8 feet. 



Perhaps the most probable explanation of these fragments is 

 to consider them the remains of originally continuous beds of 

 shale deposited with or near the sandstone, and afterwards bro- 

 ken-up and imbedded afresh by a local rearrangement of the 

 materials forming the sandstone. 



