Pont de Pierre in Quebec, Canada
September 21, 2017
Photographer: Daniel Leclerc
Summary Author: Daniel Leclerc
A natural arch is rock with a naturally-formed opening beneath an arch; a natural bridge is a particular type of arch in which the water was the natural force creating the opening. Erosion by moving water slowly ate away the rock to create the shape of this bridge and erosion will also eventually take it down.
The Pont de Pierre (Stone Bridge) is a granite bridge overhanging a small stream valley at the outlet of Lac du Pont de Pierre, between municipalities of Saint-Léonard-de-Portneuf and Rivière-à-Pierre, in Quebec, Canada. The geological formation of this stone bridge dates back approximately 10,000 years to the last ice age. It's thought that fast-moving glacial meltwater broke through a portion of a granitic outcrop, eventually forming a passage or tunnel -- the upper part today constitutes the naturally arching bridge.
Rivière-à-Pierre is well known for its granite. It's been used in the construction of the pedestal of the Statue of Liberty in New York and the pillars of the Quebec Bridge. The photo at left was taken from the opposite side of this bridge. Photos taken on August 21, 2016.
Photo Details: Top - Camera Model: Canon PowerShot SX60 HS; Focal Length: 18.1mm; Aperture: ƒ/8.0; Exposure Time: 0.300 s (1/3); ISO equiv: 250; Software: Adobe Photoshop Elements 9.0 Windows. Bottom - same except: Focal Length: 4.1mm; Exposure Time: 0.250 s (1/4); ISO equiv: 100.