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PROCEEDINGS OF THE GEOLOGICAL SOCIETY, 



of stems of trees broken off at different heights above the root, vary- 

 in height from six to twenty-five feet, and in diameter from fourteen 

 inches to four feet. There are no appearances of roots, but some of 

 the trees enlarge at the bottom. They rest upon, and appear to have 

 grown in, the mass which now constitutes the coal-seams and under- 

 lying shale, never intersecting a superior layer of coal, and never 

 terminating downwards out of the coal or shale from which the stem 

 rises. The underclay or shale often contains Stigmarise, Here 

 then, he states, are the remains of more than ten forests, which grew 

 the one over the other, but at distant intervals, during which each, 

 from the lowest upwards, was successively covered by layers of great 

 thickness of clays and solid stone, the materials of which must have 

 been arranged and consolidated under the surface of water, and the 

 vegetation of every layer in which the upright trees are fixed must 

 have grown on land. 



The formation of coal-measures like the above, and of all others 

 where there is evidence that the vegetable matter was not drifted to 

 the place it now occupies, but must have grown on the spot, is 

 then accounted for by supposing, that the land sank below the level 

 of adjoining water; that gravel, sand and mud were washed down 

 from the land that did not sink, and formed layers of clay and 

 sandstone over the submerged forest, either in sufficient quantity 

 to rise to the surface of the water and form land for the next 

 forest, which was submerged in its turn, or that a contrary in- 

 ternal movement took place, which again raised the submerged land ; 

 and that for every seam of coal, one above the other, a similar series 

 of changes must have taken place. It is to this oscillatory move- 

 ment that Mr. Lyell ascribes the formation of the above remarkable 

 phsenomena in the Bay of Fundy, and others of a like nature. 



At first sight, both theories seem well-founded, when applied to 

 the particular coal-fields described ; and it is possible that these 

 eminent and experienced geologists may be of opinion that both are 

 true, as applied to different situations. But I see great difficulties 

 to the full acceptance of either, in many of the phaenomena \vhich, 

 on a close examination, we find coal-fields generally present. As ex- 

 amples, I will call your attention to two sections that have very re- 

 cently been published ; the one a section of the western part of the 

 South Welsh Coal-field, included in the valuable series lately issued 

 from the OflSice of the Geological Survey of Great Britain, the work of 

 W. E. Logan, Esq., a Fellow of this Society, so well known to us as 

 an excellent observer, and as intimately acquainted with coal-fields, 

 and who was formerly attached to that Survey ; the other is entitled 

 a " Section of the Nova Scotia Coal-Measures, as developed at The 

 Joggins, on the Bay of Fundy, in descending order, from the neigh- 

 bourhood of West Rugged Reef to Minudie, reduced to vertical 

 thickness." It is also the work of Mr. Logan, who is now employed 

 by the Government of Canada to make a Geological Survey of that 

 country, and is contained in his Report to the late Governor Sir 

 Charles Metcalfe, and transmitted by the Governor to the Legis- 

 lative Assembly. And here I may remark, in passing, that while 



