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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 21 



merely a result of the mixture of the soft surface of the gypsum 

 with the mechanical detritus first deposited ou it. 



(7.) On the opposite side of the creek, which makes a small break 

 in the section, is a thick bed of marl, whose dip appears to be the 

 same with that of the gypsum. In general character it resembles 

 the marl underlying the gypsum. In some parts it is greenish, and 

 homogeneous in texture ; in other parts it is brecciated, and some layers 

 haA'e a brownish colour and shaly texture. In some parts it is highly 

 gypseous and contains layers of granular gypsum, one of which is 

 black, its colour being due to a small proportion of coaly or bitumi- 

 nous matter. 



(8.) Beyond the marl the shore is occupied for a short space by 

 boulder clay. Beyond this it shows a great thickness of dark shales 

 with calcareous bands, containing a few small shells ; they dip to the 

 E.S.E. at a high angle, and overlie the gypsum. They are succeeded 

 by a thick band of very hard grey and brownish sandstones and shales, 

 containing a few fragments of plants stained by carbonate of copper. 

 These are again overlaid by dark shales, and these by an enormous 

 thickness of grey and brown sandstone and shale. Some of the shales 

 in this part of the section have assumed a kind of slaty or rather 

 prismatic structure, which I have endeavoured to represent in the 



Fig. 3. 

 Shales with prismatic structure. 



sketch, fig. 3. 



At Ship Harbour, four miles di- 

 stant from Plaister Cove, the series 

 last mentioned is seen to contain 

 thick beds of grey flag and finely 

 laminated shale, and also a bed of 

 black shale with shells of Modiola 

 and Cypris. The coast sections 

 show no beds higher in the series 

 than these last; but farther in- 

 land they appear to be succeeded, 

 m ascending order, by a great de- 

 posit of grey sandstone and shale * 

 containing a bed of limestone and a 

 smaller bed of gypsum, the former 

 abounding in Prodiicta Lyelli and 

 other characteristic shells of the 

 lower carboniferous system. These 

 are followed by true coal-measures, 

 containing Lepidodendron, Cala- 

 mites, Sigillaria, Stigmaria, &c. 



In examining this section, an observer is struck by the contrast 

 between the hardened and altered sandstones and shales, and the soft, 

 light-coloured marls associated with the gypsum. Though not 

 uncommon in the gypsiferous series, this contrast is, in the case of 

 Plaister Cove, more striking than usual, in consequence of the com- 

 paratively high state of induration of the sandstones and shales. It 



* The ' Millstone grit' of Mr. Brown : see his paper on Cape Breton, Jouinal 

 of Geol. Soc. vol. i. p. 211. 



Dip of beds S. "5° East. 



a. Joints, strike E. and W. Dip S. 



b. Shale with prismatic structure. 



