218 Mr. BuDDLE on the Great Fault called the Horse 



The Coleford High Delf is the only seam of coal in which the Horse is clearly 

 developed ; it is the twenty-third seam in the Dean Forest series in the descending 

 order, and the third from the lowest. 



Whether the Horse may produce any change in the seams lying above the Cole- 

 ford High Delf, can be ascertained only by the future working of those seams ; but 

 from the regular and uniform nature of the pavement, and from the entire absence 

 of sandstone in it, there is no reason to think that the Horse goes any lower down 

 than the seam. 



On considering the various phsenomena presented by this fault, and the seam of 

 coal on each side of it, we may infer that it occupies the site of a lake which ex- 

 isted at the period of the deposition of the High Delf seam ; and that the carbon- 

 aceous matter which formed the seam was accumulated while the water was deep 

 and tranquil. 



The undulations in the top of the coal on each side of the Horse, it may be pre- 

 sumed, were occasioned by abrasion, when the water was discharged from the lake ; 

 and that the Horse itself occupies the bed of the river, by which the complete 

 drainage of the lake was effected, and which washed the coal entirely out. 



This is the more probable, as those undulations or lows appear to have been 

 formed by smaller collateral streams and rills of water. Two of the largest, marked 

 A and B, fig. 2, have been traced to a considerable extent, as shown on the Plan. 

 The other Lows have been found in the workings on each side of the drift C, D, 

 which is on the line of the section. 



The sandstone roof of the coal and the filling up of the rills which form the lows, 

 and which are a part of the roof-stone, have been formed by subsequent deposi- 

 tion, and become consolidated by pressure. 



The roof is a fine, close, granular sandstone, without ripple marks, containing only 

 a few ill-defined vegetable remains, and has every appearance of tranquil deposition. 



The fall of the Horse is conformable with that of the strata, viz. S. 31° E., as 

 far as it has been traced, and at the same rate ; but whether it may continue this 

 conformity, and rise with the seam of coal, to its outcrop, on the S.E. side of the 

 Forest Basin, has not yet been ascertained. The bed of the Horse on its transverse 

 section is nearly horizontal. 



There is no indication on the surface by which the Horse can be traced, beyond 

 the limit to which it has been explored in the pits. 



In its underground character this fault is similar to those washes or aqueous 

 deposits in many coal districts, but it differs from them in not being under the bed 

 of any river, nor in the bottom of a valley, nor does it show itself at the surface. 



In the Newcastle coal-field, all the washes which have been met with cut through 

 the whole of the strata, from the surface to that on which they repose. 



