Sundance Hoodoos EarthCache

Sundance Hoodoos

Wild Sculptures of the North

Most Unique Sandstone Sculptures in the Province

Sundance Valley was formed by the meltwaters of a receding glacier. This glacial gouge left behind a landscape of creeks, lakes, and along the valley’s eastern slope a vertical cliff. This rock wall hosts unique formations known as The Sundance Hoodoos and they stand as sculpted sentinels over the valley.

Hoodoos are formed from differential weathering where the rocks weather at different rates. Due to the cliff’s mineral composition of sedimentary and igneous rock, erosion has created some phantasmal sculptures. The thick base layers of relatively soft sandstone are covered by upper layers of hard rock. The upper layers become protective caps of resistant material sometimes a boulder, sometimes just a hard layer of shale, which help to hinder or protect underlying softer sandstone being subject to various weathering and erosive powers. Typically, hoodoos form from multiple weathering that continuously work together. Frost, wind, rain and running water all can erode the soft material if not for the protection of the cap rock. All four weathering erosion types are on display at these hoodoos:

Frost wedging (or ice wedging) happens through repeated thawing and freezing of water. When water seeps into cracks, it then expands upon freezing causing the rift to broaden.

Wind has an important effect in bringing about the erosion of rocks by sculpting the soft sedimentary material with harder grit or sand.

Rain will cause the soft layers on the side to be weathered. Cracks occurring on the top layer enable water to trickle to the soft layer and cause weathering as it falls down the vertical slope. Rainwater also reacts with carbon dioxide to form carbonic acid which erodes the shale and limestone on the top thus causing cracks.

Running Water groundwater seepage and bubbling springs along the cliff cutting paths and crevices through the softer layers of sandstone.

The Sundance Hoodoos EarthCache will require a hike along the Hoodoo trail to both the lower and upper Wild Sculpture portions to reach Reference Point 1 and Reference Point 2.
In order to log this EarthCache please complete the tasks and submit the answers to the six questions:

1.  What characteristics are needed in the two layers of rock to form a hoodoo?

2.   Why is it necessary?

3.  What else is needed for a hoodoo to form?

Task 1: Hike along the Hoodoo trail and take the Lower Wild Sculpture branch until you reach the reference point. Turn and face the vertical cliff. A hoodoo tower will be on your right. Now note the other unique formation directly in front of you and 4) describe what you observe. 5) What type of weathering most likely caused this? Do not post any pictures of this feature.

Task 2: Hike the Hoodoo trail along the Upper Sculpture Trail portion and while standing at the reference point, 6) how many freestanding fully formed hoodoos can you see?