Sand dunes are small ridges or hills of sand found at the top of a beach, above the usual maximum reach of the waves. They form from wind blown sand that is initially deposited against an obstruction such as a bush, driftwood or rock. As more sand particles are deposited the dunes grow in size, forming rows at right angles to the prevailing wind direction. If vegetation, such as Marram Grass, begins to grow on the dune its roots will help to bind the sand together and stabilise the dunes.
Most sand dunes are considered asymmetrical, meaning that if you cut down a central line, they are not identical on both sides. The side of the sand dune that faces the direction of the wind movement normally has a gentle slope, while the downwind side has a steeper slope. The downwind side of the dune is referred to as the slip face. Sand grains are blown up the gentle slope of the dune, and when they reach the top, they fall onto the slip face. When enough loose sand settles on the slip face, it can cause a small sand avalanche to occur as the sand slips down the dune.
Scoured by wind, waves and ice, sandy shores are harsh places to live. Vegetation helps stabilize dunes, but sands shift over time, continually reshaping habitats. Wild species are adapted to survive extreme temperatures, droughts and low nutrient levels. Climate and lake movements are critical in maintaining natural shoreline processes by scooping, depositing and moving sand. By definition, these habitats have less than 60% tree cover, varying between open, patchy, scattered or lightly treed.
The Erieau sand dune that you are standing on is part of this unique and globally rare sand dune system that has evolved over the last 2000 to 3000 years.
To log this earthcache, email the answers to the following questions to the cache owner. DO NOT post your answers in your log!
A photo of you, or the area around the coordinates would be nice, but not necessary to log the find.
The answers can all be found on the sign in front of you.
#1. - Why is it important to protect the dunes?
#2. - What 3 species of animals are currently endangered in Ontario ?
#3. - From reading the sign, what good is Milkweed?
Please log your find without waiting for confirmation from me.
Congratulations to chartmaker for being the first to find this cache