Notice of a Scientific Expedition. 

 Fig. 4. 



339 



a Sandstone. — 5 Shale containing small bivalve shells. — c Coal. — d Sandstone 

 and Lignite. — e Nodular argillaceous Iron.—f Argillaceous Iron with Lignites. — 

 g Thin layers of coal. — s Shale. 



Fossils. — The fossils are mostly of vegetable origin. They are 

 generally casts, or substitutions of sandstone for the vegetable mat- 

 ter, the latter having been removed without leaving a trace of ve- 

 getable structure, except the external markings. Those which we 

 consider the most remarkable at the South Joggins, were large trunks 

 of what might be called trees, belonging to the order sigillaria. 

 We saw several of these trunks, some lying in a horizontal position, 

 others erect, or rather they pierce the strata at right angles. They 

 vary in size from eighteen to thirty inches in diameter. The one 

 'we had an opportunity to examine carefully, was about eighteen 

 inches in diameter, exclusive of a thick carbonaceous bark. Beneath 

 the bark, it is superficially grooved, and resembles slightly a fluted 

 column. The carbonization of the bark in this instance and in other 

 similar ones, does not appear to have been produced by exposure to 

 heat, but it is rather a chemical process, more like the action of 

 sulphuric acid on wood, or it may be the result of long immersion 

 in water. The lower portion of that trunk, which was at right an- 

 gles to the strata, was broken away ; there were no appearances of 

 roots, hence the idea, that it grew here, may be doubted. The sand- 

 stone was deposited around it where it was vertical, but whether it 

 was a living or a dead tree, or whether its trunk was thrown into 

 and fixed in a vertical position as some are now, when washed from 

 a bank and are floating down a river, cannot now be determined, 

 but the circumstances of the case would lead most observers to the 

 conclusion, that it might have grown on or near the place it now 

 occupies. 



The most common vegetable relics of the Joggins are Lepidoden- 

 dra Calamites and Cactae. The first are confined mostly to beds of 



