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were formed in great sand-banks and mud- banks and other 

 accumulations parallel to the ever-shifting coast line of this great 

 continent — Archaia. I mention that to enable you to realise a 

 fact which I myself did not realise until about this time last year. 

 Let us now consider the physical condition of this country that 

 is supplied in the upper carboniferous times. In case of the 

 Yoredales we have evidence unmistakable of the gradual shallow- 

 ing of these oceanic waters. First of all the mud banks gradually 

 passed their way over the accumulations of the deeper waters ; 

 then in due order the coarser accumulations were pushed over the 

 mud banks, and so on until you have your 4,500 feet of Yoredale 

 rock of Pendle formed. The sand-banks and mud-banks gradually 

 filled up the area of sea, and the sea was pretty nearly converted 

 into an area of land. Then we have gradually creeping down 

 from the higher points of land the carboniferous trees, the trees 

 of which the coal was built up. We have trees of various sorts — 

 the Upidodendra, the sicjiUaricc, &c., — gradually finding their way 

 over the newly-formed land, clothing it with vegetation, which in 

 its decay contributed to the formation of the beds of peat, which, 

 compacted together and altered by heat, were converted into the 

 seams of coal so valuable to us in this district and upon which 

 our commercial prosperity depends. These trees comprised large 

 representatives of the conifers, more particularly the Salisburya, 

 and now comes an interesting fact. Did those trees find their 

 way over these great tracts of accumulation — the mud banks and 

 sand banks ? We find our answer to that by just considering 

 the evidence as to the vegetation on the land in the lower carbon- 

 iferous times. Those forests were flourishing in Scotland — in 

 that portion of Archaia — during the whole of the carboniferous 

 age : there is no doubt whatever that it was flourishing also in 

 Wales, so that what would happen was for them to descend from 

 the higher to the lower area. In that manner then this area of 

 sea was gradually converted into an area of land covered with 

 luxuriant forest. A very interesting piece of evidence in regard 

 to the position of the land is that the coal seams in a bed occur 

 as nearly as possible parallel to one another. They may be 

 inclined to any angle of the horizon ; that does not matter at all 

 because since that material accumulated great changes of level 

 locally have taken place. Not only so but when we come to 

 examine the sand banks and shales which are associated with 

 the coal seams, we have proof that after these land surfaces 

 represented by the seams of coal had been suddenly depressed 

 beneath the waters of the sea or estuary, then the sand and mud 

 banks were poured over the submerged area of vegetable accumu- 

 lation. Then they accumulated again and formed another dead 

 level on which another coal bed was formed, but in every case 

 the surface was a horizontal surface. That will lead to such a 



