Part of Gloucestershire and Somersetshire. 34T 



contrary to the general rule) it diminished gradually in the line of the dip, 

 until it disappeared altogether. 



The faults observed here were innumerable : principally ranging north 

 and south, and producing a down-throw from east to west, which varied 

 from two or three yards to twenty yards. These faults occurred at various 

 distances, from ten to fifteen yards, and thence to one hundred yards asunder. 

 They were all composed of the debris of beds of the coal formation, and one, 

 two, three, and four yards in thickness; but one fault was cut through which 

 was thirty-five yards thick. These were accompanied by smaller fissures, di- 

 verging, or " flying" from the principal one, and likewise interrupting the 

 strata, though to a less extent ; so that the whole of this northern extremity of 

 the coal-field was in a fractured and dislocated state. 



To the preceding statement I have to add, that in the slate-clay were oc- 



[casionally found thin discontinuous layers of clay-ironstone, which also some- 



' times appeared in the form of spheroidal and ovoidal nodules and masses ; 

 both the slate-clay and clay-ironstone exhibiting reed-like impressions and casts. 

 And in the slate-clay over the lower coal seam, I observed an interrupted 

 layer of sulphate of strontian, from one to two inches thick. 



In a pit lately sunk near the north-eastern edge of the field, a bed of con- 

 glomerate was met with, composed of rounded and angular fragments of slate- 

 clay and quartz compacted by slate-clay. This seems to be the lowest bed 

 of the coal formation, reposing on the fine-grained sandstone of the dell. 

 The remains of the stems and branches of plants that occasionally appear 



[in the broad belt of sandstone, may be referred in general to the variolariae 

 of Sternberg; and those of the shale and clay-ironstone of this northern ex- 



jtremity of the coal-field, to the calamites and syringodendra of the same 

 kuthor. I have not observed any felicites^ or other leafy impressions, in the 



Ishale or ironstone. 



In the north-western quarter of the field, an alluvial formation of bog iron 



[ore occurs, occupying a small space, in a superficial position *. 



b. The second sedimentary, or gypseous and saliferous Series. 



§ 25. The rocks of this series, including the calcareous conglomerate, 

 magnesian limestone, and new red sandstone and clay- marl formations, do not 

 any where appear in great force within this district ; and they constitute but 

 an inconsiderable body, when compared with the same formations in other 



* Since the preceding account was written the working of the Cromhal! quarry has been again 

 partially resumed. 



