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THE DISTRIBUTION OF ANCIENT VOLCANIC ROCKS.
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tor's Brook, Georgeville, Blue Mountain and East River of St. Mary's. These are quite like the Cape Breton and Cape Porcupine rocks, and carry copper, as they do in South Mountain, Pa., and on Lake Superior. He gives the age of these eruptions as probably pre-Cambrian, although at Arisaig they may be of any age older than Medina. Similar volcanic eruptions occur in all strata up to the base of the Carboniferous.[1] In his last report covering Pictou and Colchester counties, the same author describes Cambro-Silurian porphyries, agglomerates, fragmental felsites, breccias and amygdaloids from Moose and Sutherland rivers. A dyke-like mass of volcanic breccia occurs on Sam Cameron's brook. Similar volcanic products are also very apparent in the Devonian of these two counties, among the most interesting of which are the syenitic granites overlaid by thick volcanic deposits at the east end of the Cobequid Hills, as described by Dawson.[2] The well-known traps of northwestern Nova Scotia, along the Bay of Fundy, which furnish the beautiful zeolites and other minerals, are of Triassic age.

In New Brunswick and the Gaspé Peninsula, old volcanic rocks, like those of Newfoundland and Nova Scotia, are extensively developed. Ells and Low mention amygdaloidal traps and porphyries cutting various strata of Gaspé, up to and including the Devonian.[3] Felsitic rocks, similar to those which are better known further to the south, are rather vaguely mentioned by Robb in northern New Brunswick.[4] Ells, in his report on the same region in 1879-80, clearly describes as volcanic both acid and basic rocks. A vast area of felsite, petrosilex, porphyry and breccia, like that near St. Johns, is developed in the upper Nipisiguet river and lake Nictor. Another like it extends from the upper Upsalquitch river along Jacket river to the bay of Chaleur, while great masses of basic volcanics (amyg-

  1. ↑ Ib., 1886, P.
  2. ↑ Acadian Geology, 1878, suppl., p. 79.
    Report on the Geol. Survey of Canada, new ser., Vol. 5, 1890-91, P. pp. 147-166.
  3. ↑ Ib., 1882-83-84, E. and F.
  4. ↑ Ib., 1870-71, p. 245.
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