The Journal of Geology, May-June 1893

This episode dives into the early scientific exploration of Canada’s Laurentian Mountains, a vast stretch of ancient rock that forms the backbone of the continent’s oldest crust. Listeners will hear how 19th‑century geologists like Logan first mapped the region, defining major rock series such as the Anorthosite, Grenville, and the Fundamental Ottawa Gneiss, and how their initial ideas about “Upper” and “Lower” Laurentian layers shaped the field.

The narrative also explains the limitations of those pioneering studies—no advanced microscopes, incomplete maps, and occasional misinterpretations—highlighting the evolution of geological methods over time. By the end, you’ll gain a clear picture of the foundational rock formations beneath Quebec and Ontario, and why they remain a focal point for modern researchers seeking to untangle the continent’s deep past.