part 1] THE WESTPHALIAN", ETC. OP EAST (JLAMOllGAIf. 6^ 



^ -r, Sample of Coal from No. 2 



Coal-Pebbles. Khoi^dda Seam. 



, 7 Volatile o ? t Fixed . -, Volatile 077 Fixed 



Ash. ,. Sulphur. 7 Ash. ,, mUphur. , 



matter. ■'^ carbon. matter. -^ carbon. 



Percent. Percent. Percent. Percent. Percent. Percent. Percent. Percent. 



1 25-70 25-10 1-29 49-20 4-23 24-82 1-38 70-95 



II 21-20 22-20 1-43 66*60 2-85 25-60 1*331 71-55 



III 5-60 24-00 1-47 70-40 2-60 27-20 1-337 70-20 



IV 3-40 23-30 1-28 73-30 



If we believe tliat the coal-pebbles were originally pellets of 

 peatj matter rolled about under littoral conditions, then we may 

 enquire how it is that the coal-pebbles now found are composed of 

 pure coal, and are free from any grains of sand embedded in its 

 mass. 



On the other hand, if we are led to believe that the coal-pebbles, 

 owing to their rounded and smooth surfaces, have been derived 

 from coal-seams which had already hardened into such a state as 

 to allow of the coal being transported by the action of water from 

 the position in which it originally rested to the place where it is 

 now found, then we must conclude that the coal-seam itself 

 was, when degradation took place, composed of young coal. The 

 chemical analyses show that the amount of fixed carbon and ash 

 varied in the coal-pebbles ; but the general results prove that in 

 quality the coal was very similar to the No. 2 llhondda coal. 



If the origin of these coal-pebbles is to be sought on the latter 

 hypothesis, then we must conclude that a considerable lapse of 

 time occurred between the deposition of No. 3 and No. 2 Rhondda 

 Seams and the seams below, because the interval must have been 

 such as to allow the peaty matter to harden into the solid state 

 of coal by the pressure of sediments now forming the strata above 

 the seams. This, in itself, would imply ancient sea-floors with 

 their sediments hardened into a compact mass, their uplift into a 

 land surface, again to be channelled out by the action of water 

 so as to allow of these coal-pebbles travelling from their original 

 positions to the position in which they are now found. Assuming 

 that this was really the case, then we have, possibly, some answer 

 to the great increase in the number of species of plants at this 

 juncture : namely, at the horizons of No. 3 and No. 2 Rhondda 

 Seams, because we find no fewer than 43 new species occurring 

 here. Stated briefly, there is at the base of the Staf- 

 fordian Series a lithological change, sandstones taking the 

 place of shales : the former contain smooth and rounded coal- 

 pebbles, the plant-remains from which are characterized by an 

 inrush of new species. A question that naturally arises is — 

 Would the interval of time at this point represent a geological 

 break of sorts ; and again, would the increase of species represent 

 a palseontological break ? 



I believe that some determining factors operated between West- 

 phalian and Staft'ordian times, and if evidence can be procured 

 over an extensive area to establish the fact that derived coal- 



