Ontario's Natural Underground Wonder
A Family Owned and Operated Site

GEOLOGICAL TIME CHART

The limestone you walk through when you visit the Bonnechere Caves was deposited as layers of mud and silt during the Ordovician time period. The Ordovician is thought to have been somewhere between 400 and 500 milion years ago. That took place before the development or evolution of the fish and well before dinosaurs!!

Geological Time Chart
Geological Time Chart