232 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



it may have originated, first, " from a hardening of bitumen," or, sec- 

 ond, by the^bituminization of woody matter under continued pressure." 



In 1853 Dr. Dawson 1 reported upon the South Joggins as follows: 



In this region is represented a series of rocks, 14,000 feet in thickness, 

 extending from the " massive limestone of the Lower Carboniferous 

 series to the top of the Carboniferous formation." 



The author gave a detailed account under twenty-nine divisions of a 

 section in the middle of the formations, some 2,800 feet in thickness. 

 The rocks consist of shales and clavs containing plant remains, black 

 carbonaceous shales intercalated by thin beds of coals, and sandstones 

 showing ripple-marks and erosive effects previous to the deposition of 

 the superimposed strata. Trunks of trees in situ, covered with Spiror- 

 bis, were found embedded in these sandstone strata, which contained 

 Catamites and Sigillaria. Stigmaria, Cypris, and Modiola were quite, 

 numerous in the underclays. Some new facts are noticed showing the 

 relation of Stigmaria and Sigillaria, and attention is called to the oc- 

 currence of Coniferous trees, Calamites, and Poacites, together with 

 animal remains, consisting of scales, teeth, jaws, spines, and coprolites. 

 An abstract is added of Mr. Logan's section of South Joggins Coal 

 Measures. (See p. 239-241.) 



Messrs. Poole 2 (Henry) and Dawson (J. W.) in 1854 compared the 

 Albion Coal Measures with the section at the Joggins. 



The thickness of the Albion Measures varies. While, according to 

 Mr. Logan, the Joggins section showed seventy-six coal seams aggre- 

 gating 44 feet, and Mr. Brown's section at Sydney, thirty-one seams 

 showing 37 feet, at Pictou there are only two seams 60 feet in thick- 

 ness. At the Albion mines the argillaceous beds are very thick, while 

 the sandstones and shales seen at the Joggins and Sydney are absent. 

 The coal beds with their associated rocks seem to be unconformable 

 with the coal formation immediately below. This is explained by un- 

 equal deposition. 



In the Albion mines occurs a thick, reddish conglomerate above the 

 Coal Measures, which has no equivalent in the other mines of Nova 

 Scotia. Its outcrop extends across the valleys of East, Middle, and 

 West Hivers, Pictou, and dips toward the north. This is considered as 

 the base of the " Newer Coal Formation." < 



A detailed account of the great bed is added. 



In 1856 Mr. Dawson 3 gave his views regarding the classification of 

 the rocks of Nova Scotia in a paper before the American Association. 



Nova Scotia is occupied by rocks of the Silurian, Devonian, and Car- 

 boniferous series, and sandstones superseded by traps. The Carbon- 



1 Dawson, J. W. : On the Coal Measures of the South Joggins, Nova Scotia. Quart. Jour. Geol. Soo., 

 vol. 10, 1854, pp. 1-42. 



2 Poole, Henry, and Dawson, J. W. : On the structure of the Albion Coal Measures. Quart. Jour. 

 Gcol. Soc, vol. 10, 1854, pp. 42-51. 



3 Dawson, J. W. : On the parallelism of the rock formations of Nova Scotia with those of other parts 

 of America. Am. Assoc. Proc, vol. 10, Pt. 2, 1856, pp. 18-25. 



