8. Jasper Conglomerate (1846)

Jasper Conglomerate

This striking and distinctive rock was used for the cornerstone of the Geological Survey of Canada’s headquarters at 601 Booth Street in Ottawa, built in the 1950s. The inscription reads "Precambrian Jasper Conglomerate Bruce Mines, Ontario from Huronian Rocks, Named By Sir William Logan, First Director, Geological Survey of Canada.”

The rock comes from the Lorrain Formation and is over 2.2 billion years old. It is found northwest of Bruce Mines, near Sault Ste. Marie – the site of the first copper mines in Canada and active from 1846-1875. It contains pebbles of red jasper, white quartzite, semi-transparent quartz, and black chert subsequently metamorphosed within a coarse-grained sand matrix. The jasper pebbles themselves may be derived from older Archean iron formations aged 2.7 billion years.

Because of its attractive appearance and association with William Logan, the rock continues to be used by the Survey for presentations and ceremonial gifts.

Category: Rocks, Fossils, Minerals and Meteorites

Decade: 1840s

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