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GEOLOGY OF THE TORONTO REGION

 

Prasopora selwyni.

Dalmanella testudinaria. Rhynchotrema inequivalve. Orthis tricenaria.

Rafinesquina alternata. Hormotoma trentonensis. Protowarthia cancellata. Isotelus gigas.

Bumastus milleri.

Ceraurus pleurexanthemus.

Resting conformably on the grey shaly lime-stones there are 150 to 250 feet of black bituminous shales belonging to the ti tica and Collingwood formations, easily attacked by the weather, so that they are generally buried under the drift; but low exposures of them may be found near Lake Ontario at Bowmanville, Oshawa and Whitby, and also near Coiling-wood, at the south end of Georgian Bay. The shale has a distinctly bituminous odor when broken, and fragments put on a fire burn for a time, though the mass that is left still retains its shape. Oil was distilled from the shale at Collingwood in early days, but the discovery of petroleum put an end to the industry. At several points the black and partly combustible shale has roused false hopes of the finding of coal.

The shale is often very fossiliferous, iron pyrites being a frequent fossilizing material. Graptolites and certain trilobites, such as Triarthrus beckii and Ogygites canadensis (formerly called Asaphus) are

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