168 Mineralogy and Geology of apart of Nova Scotia. 



material to the ore, which may be worked in this section of 

 the province. 



Four miles southeast of this place a very important and 

 extensive bed of iron ore exists, in the clay slate of the South 

 Mountains, which we shall describe after noticing generally 

 the whole transition clay slate formation of Nova Scotia, 

 commencing at the eastern extremity of the district of Pic- 

 tou, and extending west south west, through the province to 

 St. Mary's Bay, where it approximates to the secondary trap 

 rocks, and is connected with them by Digby Isthmus, which 

 is composed of sandstone, as observed in the first part of 

 this article. For this connexion, see the map.* This rock pre- 

 sents a larger extent of surface, than any other in the prov- 

 ince, forming more than one third of the whole face of the 

 country. It presents every where a uniform geological char- 

 acter, and containing fossil organic remains, belonging to the 

 marine world alone, (no vestiges of the vegetable kingdom 

 being discoverable,) it must obviously, according to the 

 great geological division of rocks, be regarded as transition, 

 and as having existed long before the neighboring plutonic 

 rocks had emerged from the central regions of the earth. 

 That this rock is older than the trap rocks we have addition- 

 al, and almost decisive evidence, derived from another source, 

 which we shall state by and by, when our observations are 

 directed more particularly to the iron ore bed which we 

 have no hesitation in saying is co-extensive with the whole 

 formation. 



The direction of the strata composing this formation is 

 uniformly north, G0° east, dipping at an angle of 50° or 

 60°, from the horizon. The color of this rock on fracture, 

 is black, greyish or bluish black. Its structure is slaty or 

 fohated, frequently separating by a gentle blow into broad 

 sheets which are sufficiently smooth and compact to be em- 

 ployed for writing slate. This is the case at Rawdon, where 

 it is obtained for this purpose, and extensively quarried for 

 roofing slate. In other places being less distinctly foliated, 

 its tendency is to break into huge rhomboidal fragments, as 

 it has natural seams both in the direction of, and at right 

 angles with its stratification. This renders it a valuable build- 

 ing material as it forms convenient shapes for rearing walls 



In Vol. XIV. 



