232 THE CARBONIFEROUS SYSTEM. 



Carboniferous rocks generally. The shales containing these fossils 

 have been singulaidy disturbed and contorted, and they contain a vein 

 of a remarkably pure and beautiful bituminous substance, allied to 

 pitch-coal, and of great value as a material for gas-making. This 

 substance unfortunately became a subject of litigation ; and as one 

 point in dispute was whether it should be called coal or asphaltum, . 

 scientific gentlemen were summoned from the United States as 

 witnesses, and the most discordant opinions were given, both as to 

 the name of the mineral and its geological age. This was not 

 wonderful in the circumstances, for the substance was really a new 

 material, intermediate between the most bituminous coals and the 

 asphalts, and the geologists examined had enjoyed very few oppor- 

 tunities of studying that very remarkable group of Lower Carboniferous 

 rocks to which the deposit belongs. Consequently some, in all sin- 

 -.  cerity, called the mineral coal, others asphalt ; and some maintained 

 that it was in the true Coal formation, while others believed it to be 

 in the Old Red Sandstone. Only one of the geologists employed, Dr 

 Percival of New Haven, assigned the deposit to its true geological 

 position, as subsequently ascertained by Sir Charles Lyell and the 

 writer, and stated above. To give an idea of this singular deposit, I 

 quote the following details from a paper contributed by me to the 

 Geological Society of London : — 



" The pit for the extraction of the mineral is situated on the south 

 side of Frederick's Brook, a small stream running eastwardly into 

 the Petitcodiac, and near the junction of two branches of the brook. 

 In approaching the mine from the south, the shales are seen in nearly 

 a horizontal position in a road-cutting. This may be a deceptive 

 appearance. Dr Percival, however, considers it the true arrangement 

 at this point. At the pit-mouth the beds dip to the south at angles 

 of 50° and 60°, and consist of gray and dark-coloured thin-bedded 

 bituminous shales; and these shales appear with similar dips on the 

 south branch of the brook. The outcrop of the coal is not now seen, 

 but in a line with it I observed a remarkable crumpling and arching 

 of the beds in the bank of the brook, at the point where the south- 

 wardly dipping beds above noticed meet a similar or the same series 

 dipping to the north-west ; this is represented in Fig 63. The 

 outcrop of the coal in the bed of the brook was, as I was informed, 

 very narrow, and the appearances now presented are as if the shales 

 had arched over it. On the northern side of the arch above referred 



to, and in the north branch of the brook, are seen a thick series of 

 O . 



bituminous and calcareous shales, with three beds of sandstone, the 



whole dipping to the north-west at a high angle. The strike of 



