Saint David's Buried Gorge facts for kids

Saint David's Buried Gorge is like a secret ancient river path hidden deep underground near the Niagara Falls. Imagine a river that flowed over 22,800 years ago in the area we now call the Niagara Peninsula. This old river, called the Saint David's River, was there long before a giant ice sheet, known as the Wisconsin glaciation, covered the land during the Last Glacial Period.

When this massive ice sheet finally melted and moved away about 12,000 years ago, it left behind a lot of fine rock dust and mud, called glacial silt, and many rocks. These materials completely filled up the old river valley and gorge, burying it out of sight.

About 4,200 years ago, the mighty Niagara River was slowly moving backward, or "receding," towards Lake Erie as it carved out the famous Niagara Falls. As the Falls kept moving, it eventually bumped into this hidden, buried gorge. When the river hit the soft glacial silt filling the gorge, it quickly changed its path. The powerful water washed away most of the silt, and the river started flowing through parts of the ancient gorge again. This amazing event helped create the swirling waters of the Niagara Whirlpool. Today, the Niagara River still flows through a section of this ancient, reclaimed gorge. Another part of the old gorge stretches out into Lake Ontario at a different spot from where the Niagara River enters. Experts believe this buried gorge is about 4,000 feet (1,219 meters) long, 1,000 feet (305 meters) wide, and 300 feet (91 meters) deep.

Exploring the Buried Gorge

What is a Buried Gorge?

A buried gorge is like a hidden valley carved by an ancient river. Over thousands of years, natural events, often giant glaciers, can fill these valleys with dirt, rocks, and mud, completely hiding them from view. The Saint David's Buried Gorge is a perfect example of this. It's a reminder of how much the Earth's surface has changed over time, especially due to the power of ice ages.

How the Gorge Was Formed

The story of the Saint David's Buried Gorge began over 22,800 years ago. Back then, a river flowed freely, carving a deep valley into the land. But then, a huge ice sheet, like a giant frozen blanket, slowly moved across the continent. This was part of the last big ice age. As the ice sheet melted and retreated, it left behind a lot of crushed rock and fine mud. This material filled up the old river valley, burying the gorge completely. It was hidden for thousands of years, waiting to be rediscovered.

Niagara River's Big Discovery

Fast forward to about 4,200 years ago. The Niagara Falls wasn't always where it is today; it has been slowly moving backward, or "receding," over time. As the Falls continued its journey, it eventually reached the spot where the Saint David's Buried Gorge was hidden. When the powerful Niagara River encountered the soft, loose material that filled the ancient gorge, it quickly dug it out. The river changed its course to follow this old path, washing away most of the buried silt. This dramatic event was a key part of how the famous Niagara Whirlpool was formed, where the river water spins in a giant circle. Today, the Niagara River flows through a part of this ancient gorge, showing us where a river once flowed so long ago.

Tunnels Under the Earth

In the 1950s, a company called Ontario Hydro, which makes electricity for the province, started digging two big tunnels. These tunnels were meant to carry water from the upper Niagara River to the Sir Adam Beck Hydroelectric Plant, which uses the water's power to create electricity. However, when the tunnel builders reached the Saint David's Gorge, they had a problem. The gorge was filled with loose silt, which was too soft and unstable to dig through safely. So, they had to bring the tunnels to the surface to go around the gorge.

Much later, in 2013, an even newer and bigger tunnel project, called the Niagara Tunnel Project, was finished. This time, engineers learned from the past. They designed the new tunnel to go much deeper, boring right underneath the old gorge. This way, they avoided the tricky, loose ground and could build a strong, stable tunnel to help generate more clean electricity.