Geology: Fundy's hidden story
Covered by the soil and the forests or guarded by inaccessible, tide-washed cliffs, the geology of Fundy National Park is a well-kept secret. There are ways, however, to touch this ancient heart of Fundy. Exploring the beaches of the Bay of Fundy, hiking along the deep river valleys and even travelling over the Caledonia Highlands, you can piece together the story which is as rich and varied as that of the Earth itself.
The Bay of Fundy Coast
While exploring the beaches and learning about the amazing Fundy tides, let your eyes wander back to the land. You will find steep cliffs which are being sculpted by the daily movements of Fundy's giant tides. In fact, the water has exposed the bedrock of the planet for most of the coastline of the park. This rock has a story to tell.
Around Alma and Herring Cove the story is one of rivers and jungles. The grey and beige rocks forming the impressive cliffs of Owl's Head are made of sandstone. This rock used to be sand and mud which a vast and ancient river lay down during the Carboniferous era (about 325 million years ago). Along this river there was a lush, tropical jungle. You can read this incredible story if you take a walk along the beach near the town of Alma. The rock has a fine sandy look to it and contains many black plant fossils and thin seams of coal.
The story is considerably older at Point Wolfe where volcanoes and the movement of the continents have formed the oldest rocks in the park. Walk down the steps to Point Wolfe beach and as soon as you reach the beach you will notice some grey, green rocks forming a low cliff along the right side of this inlet. The rock has been smoothed by the tides but the story can still be deciphered. Volcanoes erupting ash and lava created offshore islands during the pre-Cambrian era (one billion years ago). Afterwards, during a collision between the continents of Europe and North America, these volcanic islands were bulldozed into the mainland. Look for the white quartz veins, swirling folds and criss-crossing fractures in the rock, which tell of this transformation. Rocks, which have undergone changes due to the heat and pressure of continental collisions, are called metamorphic rocks.
Point Wolfe is a geologist's paradise. Opposite the grey rocks, you will notice rusty, maroon-coloured cliffs towering above you. The rusty-red cliffs tell a tale of crumbling mountains. These mountains were created by the ancient pre-Cambrian volcanoes and by the collision of Europe and North America. At one time they rivalled the Rockies in massive splendour. But they were worn down, or eroded, by the passage of time. Water and gravity piled all of the debris at their feet. These boulders and pebbles were later cemented together to form a new rock which we call the Hopewell conglomerate. If the name Hopewell sounds familiar to you, you are probably thinking of the Rocks Provincial Park at Hopewell, where the conglomerate is also found. You can also find it at Herring Cove. Don't forget to examine all of the rounded rocks and pebbles that have been cemented together to form this conglomerate. At one time they were the backbone of towering mountains.
The Caledonian Highlands
Fundy National Park is more than its coast line! Most of the park is made up of rolling and rounded mountains which form the Caledonian Highlands. Here, the story is mostly hidden under the trees and soil but if you explore the more than 100 km of hiking trails which criss-cross the park you may run across a wide variety of rocks. Or, as you drive along the provincial highway 114, check out the road cuts which have exposed some outcrops. The rocks you see are the exposed roots of the vast mountain chain referred to earlier. Erosion over the ages has reduced these mountains to the Caledonian Highlands of today. You will find granite, which originated in the Earth's interior and volcanic rocks.
The Caledonian Highlands have played an important part in another story: the Ice Age. During this last glacial period, the highlands had their own ice caps. When the ice finally melted, about 13 000 years ago, it released all of the sand and gravel which had been incorporated into it over the years. This rocky and poor soil covers the surface of the land today. This explains one reason why farming was never easy for early settlers around Fundy. The soil is too poor. In some areas, the melting ice formed rivers of glacial water. These rivers laid down great quantities of sand and gravel.
MacLaren's Pond, near the Amphitheatre in the Headquarters area is part of this melt water story. As a glacier melted and retreated up the golf course valley, tonnes of sand and gravel were washed out. At one point a huge block of ice broke off from the glacier and was left stranded by the melting ice. It was soon buried in the sediment. Eventually the ice melted and the sand and gravel caved in around it. The depression filled with water. It is called a kettle pond. If you explore the Headquarters area of the park, you can find out all about this glacial story by following a series of interpretive signs.
The River Valleys
Moving inland from the massive cliffs of the Bay of Fundy coastline, the geological story becomes more subtle. One of the best avenues to explore this story is to be found in the river valleys of Fundy National Park.
Moving water has carved through the more recent pages of geological history to reveal just what a long story it is. For the last 10 000 years, the rivers have been carrying away tonnes of rocks and sand which were dumped into the valleys by the retreating glaciers of the last Ice Age. The Upper Salmon River and the Point Wolfe River existed before ice covered the land! Now, gradually, the running waters are carrying this glacial till into the Bay of Fundy. Go to Kinnie Brook where the valley is still full. During many times of the year, the brook disappears underground, filtering through a thick layer of glacial gravel.