Mineralogy and Geology of apart of Nova Scotia, 145 



Portions of ensiform leaves resembling those of the Iris, or 

 blue flag, were here observed, lying between, and included 

 within the strata of sandstone. 



The whole northern coast of the Basin of Mines, with 

 the exception of the capes and islands of trap before des- 

 cribed, is composed of strata of sandstone and shale, alter- 

 nating with each other, and presenting to the sea, the edges 

 of their strata, which are finely exhibited by this natural sec- 

 tion. They do not attain a great elevation, rarely exceeding 

 one hundred feet, and where exposed to the waves, the strata 

 have suffered much from their violence, and the shale is al- 

 ways worn away, exhibiting the bold ridges of sandstone 

 strata, contrasted with the deep furrows occasioned by its 

 decay. The strata of these rocks are from a foot to four 

 feet in thickness, and are alternately stratified with each oth- 

 er in great regularity : no limit being found to this alterna- 

 tion, we are unable to say which rock is finally subordinate 

 to the other. Near the village of Parsborough, the red 

 shale appears to predominate, and constitutes a bed more 

 th iti one hundred yards thick, which is beaiitifully spoited 

 With green, and contains occasionally scattered crystals of 

 yi^ilow iron pyrites. East of this bed the sandstone appears 

 in Tiore powerful strata, and more than compensates for the 

 thickness of the shale just mentioned. It f »rms a junction 

 with the trap of Swan's Creek, where it includes numerous 

 beds arid veins of gypsuni, which is of the laminated and 

 fibrous kind. It is occasionally of a delicate flesh color, and 

 the intersecting laminae are more than a foot in ientjth. The 

 laminated and crystallised gypsum is not sought for expor- 

 tation so much as the amorphous varieties, which ahhouajh 

 not so pure, exist in large beds, and are more profitably 

 wroui^nt, while they bear the friction and pressure of trans- 

 portation wittiout crumbling to pieces, as would inevitably 

 haopen to more friable crystalline varieties. At Tower Hill, 

 twelve miles east of Parsborough, the sandstone again meets 

 the trap, which forms but a small part of the precipU >U3 

 summit, and has no amygdaloid in connexion with it. The 

 united sandstone and shale however, exhibit a most singular 

 appearance, and becoming vesicular, aff'ict a curious imua- 

 tion of amygdaloid, the place of which it occupies in rela- 

 tion to the trap. These rocks forming the base of the preci- 

 pice, are of a fine texture, ^nii contain a large proportion of 

 argillaceous matter, colored with oxide of iron. 



Vol. XV.— No. L 19 



