Monteregian

A Monteregian is a hill that is part of a distinctive group of geological formations found in southwestern Quebec, Canada, specifically in the St. Lawrence Lowlands. These hills are often referred to as the Monteregian Hills. The term "Monteregian" is derived from Mont Royal, the most prominent and iconic of these hills, located in Montreal.

The Monteregian Hills are characterized by their isolated, often steep-sided profiles, rising dramatically from the relatively flat surrounding terrain. Geologically, they are the eroded remnants of alkaline intrusions that pushed up through the Earth's crust millions of years ago. These intrusions, primarily composed of igneous rocks like essexite, shonkinite, and foyaitic rocks, cooled slowly beneath the surface. Subsequent erosion by glaciers and rivers over geological time has exposed these resistant rock formations, leaving them as prominent landmarks.

There are nine recognized Monteregian Hills: Mont Royal, Mont Saint-Bruno, Mont Saint-Hilaire, Mont Saint-Grégoire, Mont Johnson, Mont Yamaska, Mont Shefford, Mont Rougemont, and Mont Pinnacle. Each hill possesses unique characteristics and ecosystems, often supporting flora and fauna distinct from the surrounding agricultural land. Their significance extends beyond geology, encompassing ecological, historical, and cultural importance for the region.