NERBUDDA DISTRICT. 157 



four feet thick, and four beds of from one to two and a half feet thick ; 

 and the quality of the coal is good throughout. If however we are correct 

 in the conjecture that in some cases the same bed has been brought 

 twice to the surface by a fault, then the real aggregate thickness of the 

 beds below would be reduced to about 10 feet 8 inches. 



We may here remark that the thickness of the upper sandstones, 

 (those which were described at the top of our section, and stated closely 

 to resemble those again found below it in descending the stream) al- 

 though not capable of being measured, must be very considerable; 

 and the question of the estimation of its amount will be hereafter 

 discussed. 



Reverting to the subject of the faults, which we have above stated 



Faults 3 probable ef- m ^ S0 haVe sllifted the beds aS t0 brin S the coal 

 fect " marked A in our section to the surface again, in 



the position marked A', it will be found that a vertical shift of 45 or 

 50 feet will satisfy all the conditions. The dip of 15° may be as- 

 sumed to be constant, and for beds inclined at so small an an»-le 

 a displacement equal to the thickness of the beds intervening be- 

 tween the two out-crops of the coal, would be sufficient to account 

 for their present relative position, on the supposition that they are 

 in reality parts of the sauie layer. Although however, taking into con- 

 sideration the similarity in lithological character of the two sets of 

 beds noted, it certainly does seem probable that the set found between 

 the two coal seams, is merely a repetition of that seen immediately above 

 the higher of those seams, yet this is not necessarily the case ; it is quite 

 possible that no fault exists, and all the beds may be distinct, in which case 

 the similarities mentioned are naturally accounted for on the ordinary 

 supposition that conditions such as produced the former, again in the 

 same order of succession, obtained during the accumulation of the 

 latter series. 



Again, we find several breaks in continuity occurring below the point 



