Coal-formation and Gypsum of Nova Scotia. 147 



The stratified rocks of Nova Scotia, more ancient than the car- 

 boniferous, consist chiefly of nietamorphic clay-slate and quartzite, 

 their strike being nearly east and west. Towards their northern 

 limits these strata become less crystalline and contain fossils, some of 

 which Mr. Lyell identified with species of the upper Silurian group, 

 or with the Hamilton group of the New York geologists. 



The remaining fossiliferous rocks, so far as they are yet known, 

 belong to the carboniferous group, and occupy extensive tracts in 

 the northern part of the peninsula, resting unconformably on the pre- 

 ceding series. They may be divided into two principal formations, 

 one of which comprises the productive coal-measures, agreeing pre- 

 cisely with those of Europe in lithological and palaeontological cha- 

 racter ; the other consists chiefly of red sandstone and red marl, 

 with subordinate beds of gypsum and marine limestone; but this 

 series is also occasionally associated with coal grits, shales, and thin 

 seams of coal. 



A variety of opinions have been entertained respecting the true 

 age of the last mentioned, or gypsiferous formation ; and it is the 

 purport of this paper to show, first, that it belongs to the carboni- 

 ferous group ; secondly, that it occupies a lower position than the 

 productive coal-measures. These last are of vast thickness in Nova 

 Scotia, being largely developed in Cumberland county and near 

 Pictou, and recurring again at Sydney, in Cape Breton. In all these 

 places they contain shales, probably deposited in a freshwater 

 estuary, in which several species of Cypris and Modiola abound. 

 The plants of these coal-measures belong to the genera Catamites, 

 Stigmaria, Sigillaria, Lepidodendron, Pecopteris, Neuropteris, 

 Sphenopteris, Nceggerathia, Patmacites, Sternbergia, Sphenophyl- 

 tum, Asterophyllites and Trigonocarpum, with which are the trunks 

 and wood of coniferous and other trees. Upon the whole nearly 50 

 species of plants have been detected, more than two-thirds of which 

 are not distinguishable from European species, while the rest agree 

 generically with fossils of the coal formation in Europe. 



The internal cylindrical axis of petrified wood in the Stigmaria of 

 Nova Scotia exhibits the same vascular structure, and the same 

 scalariform vessels, as the English specimens. 



Mr. Lyell next describes the gypsiferous formation, especially the 

 marine limestones of Windsor, Horton, the cliffs bounding the estuary 

 of the Schubenacadie river, the district of Brookfield, and the cliffs 

 at the bridge crossing the Debert river, near Truro. Several species 

 of corals and shells are common to all these localities, and recur 

 in similar limestones in Cape Breton. In this assemblage of organic 

 remains we find a Crustacean intermediate between the Trilobite and 

 Limulus, Orthoceras (two species), Nautilus, Conularia, Encrinus, 

 Cyathophyllum, besides some species of the carboniferous limestone 

 of Europe, such as Euomphalus l&vis, Pileopsis vetttstus?, Avicula 

 mitiqua, Pecten plicatus, Isocardia unioniformis, Producta martini, 

 P. scotica ?, Terebratula elongata, Fenestella membranacea ?, Cerio- 

 pora spongites, Goldf. Eor assistance in determining these, the 

 author has been greatly indebted to M. de Verneuil. 



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