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Western Brook Pond


What is Western Brook Pond?
Western Brook Pond started out as a stream cut valley. During the last ice age, glaciers carved the valley into a deep U-shaped trough. The basin is very deep, reaching 165 meters (541 feet) in places. When the glaciers began to retreat, this was most likely an ocean fjord, but eventually the land rebounded, elevating the basin above sea level. Today, glacial moraines act as a dam, trapping the freshwater inflow to form the pond.

(Photograph of model at Western Brook Pond Boat Landing)

Aerial View of the Pond
This aerial view of the pond shows the drainage basin of the pond. The inflow of water to the pond is so low that it takes an estimated fifteen years for the pond's water to completely replenish itself, whereas in most lakes, this occurs once or twice a year. Because it takes so long for the water to flow out of the lake, it is important that no pollution is introduced into the lake.

Waterfalls like this one are an important source of inflow into the lake. To get an idea of the size and height of the waterfall, look at the full-size trees in the lower right corner of the picture.
www.mnsfld.edu Hanging Valleys
In some areas, smaller glacial flows joined the main arm of the glacier, resulting in hanging valleys like the one pictured here. Hanging valleys are U-shaped and have steep sides, just like the larger trough containing Western Brook Pond.
Bedrock Geology and Erosion
The bedrock of the cliffs and the area surrounding the pond is part of the Grenville basement, which is made up of Precambrian gneiss with igneous intrusions of black diabase. Over time, sections of the cliffs have started to weaken and collapse, forming rubble cones, which are able to support trees better than the steep cliffs are. Where the walls are vertical, they are more stable and less likely to collapse.

Here are some more pictures of the cliffs surrounding the pond.


click on any picture for a larger view