Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/681

 that these rocks were the type of a considerable proportion of the Nova-Scotian Silurian system. My field experience since then has confirmed this opinion. All the Upper Silurian rocks that I have examined appear to be repetitions of the Arisaig series, wholly or partially fossiliferous, and partially metamorphic, or highly metamorphic, and without appearance of fossils, as at Arisaig itself. I then observed, in connexion with the B, or second lowest member of my Arisaig series, " that the conditions under which it had been formed appeared to have been of a kind not the most favourable to the development of life." This statement requires modification. I have found B strata in Arisaig, and elsewhere, somewhat rich in fossils. At Arisaig Cove, south of the pier, I found, in the summer of 1868, many beautiful specimens of Orthids, Trilobites, Crinoids, and Favosites. In other localities I found abundance of Linguloe of various species, and a peculiar fossil, singularly and beautifully milled.

I also observed, in my former paper, that A had been transformed into porcellanous jasper at Arisaig pier, Frenchman's Barn, &c.

In the summer of 1868, I found, connected with these jaspideous rocks, beds of soft material resembling silicates of magnesia, but which are now found to be silicates of alumina, which may be employed for ornamental and useful purposes.

In reference to A and B, Dr. Dawson has observed, in his ' Acadian Geology,' 2nd edition, that Dr. Honeyman had discovered strata at Doctor's Bock which appeared to be somewhat lower than his lower Arisaig, and that they were possibly on the horizon of the Medina and Oneida of the United States.

After careful consideration, I have come to the same conclusion, and regard the whole Arisaig series as equivalent to the Anticosti group. Both localities are situate in the same meridian and in opposite positions on the Gulf of St. Laurence.

To the east of the fossiliferous group of Arisaig, and in the township of Arisaig, is a band of crystalline rocks, which I discovered in the summer of 1868. These lie on the shore, and extend to some distance inland. They appear to be bounded on three sides by carboniferous rocks, the fourth side being obscure, covered by the waters of Northumberland Strait. A small patch of Lower Carboniferous conglomerate with intrusive greenstone, lying in Malignant Cove, separates these from the Upper Silurian already noticed. The whole band is peculiar and interesting ; but the most remarkable feature is a broad stratum of ophiocalcite with ophiolite. The former appeared strikingly to resemble some of the ophiocalcites of the Laurentian exhibited in the Canadian Court at the Paris Exhibition of 1867. On comparing a polished specimen with a specimen of ophiocalcite from Bohemia, containing Eozoon bohemicum, I was almost persuaded that the Nova-Scotia specimen was Eozoonal too. I took the specimen subsequently to Montreal. Dr. Sterry Hunt, on showing it to Sir V. E. Logan in my presence, expressed the opinion " that he thought it to be Laurentian." Dr. Dawson told me that Dr. Hunt had said to him that he considered the rocks I had found to be Laurentian.

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