FREE PARKING: DO NOT park anywhere other than the designated parking area on Julian drive.
Parking cords: N 44° 52.643 W 081° 21.204
RESTRICTED PUBLIC ACCESS: the entire beach area is public however local residences have obtained permission to restrict public access over night only from 9:30 pm until 7:00 am.
Please only visit the beach during the daytime.
SAFETY: BEWARE of children and pets AT ALL TIMES near the water.
CITO – Cache In & Trash Out and respect all plants and wildlife.
We hope you enjoy this beautiful area and amazing rock beach!
~ The purpose of this earthcache is to learn about and observe
Weathering of Limestone ~
Please read the cache page.
At the posted coordinates, please observe the 3 layers of limestone visible. To claim a smiley find for this EarthCache, describe the differences between these layers by answering the following questions and send these answers to the Cache Owner’s profile please. (click on our name under the cache title)
1) Four feet from GZ [ground zero] straight toward the water, find a chunk of exposed non-weathered limestone. Observe and explain the physical difference between this exposed limestone and the weathered limestone above it.
Back at GZ
Top Layer Observation:
2) Describe the result of weathering seen here in terms of the physical appearance of this layer. (NOT the colour)
3) What is the average depth of the holes in this layer?
4) What is the thickness of this layer?
5) Explain why you think this layer is a) softer OR b) harder than the middle layer.
Middle Layer Observation:
6) Describe the result of weathering seen here in terms of the physical appearance of this layer. (NOT the colour)
7) What is the thickness of this layer?
8) Explain why you think this layer is a) softer OR b) harder than the top layer.
Deepest Layer Observation:
9) Describe the result of weathering seen here in terms of the physical appearance of this layer. (NOT the colour)
10) What is the average depth of holes in the deepest layer?
11) What is the average diameter of the holes in the deepest layer?
On your walk back to the car, stop at Waypoint #2
N44 52.589 W81 21.296
Observe the large round hole in the boulder under the water.
12) Guess the diameter. Explain how you think this hole formed.
Description
At the posted coordinates you will find weathered limestone rock.
Limestone
Limestone is a soft sedimentary rock. Sedimentary rocks form from the decaying remains of organic and inorganic material (sand, pebbles, rock, minerals, plant, animal, etc.) that have accumulated and been deposited under water. Eventually the layers settle, over billions of years, producing sediment layers.
Weathering
Weathering is the process of breaking down or wearing away rock into smaller pieces. There are chemical and physical weathering processes.
Physical:
Mechanical weathering: happens when water gets into rock cracks and freezes expanding the cracks wider.
Organic weathering: happens when plant roots or acids break up the rock.
Chemical:
Chemical weathering: happens when rocks and minerals are decomposed or decayed by chemicals.
When fossil fuels such as coal, oil and natural gas are burned, carbon dioxide and sulphur dioxide escape into the air. These dissolve in the water in the clouds and make the rainwater more acidic than normal. When this happens, we call the rain ‘acid rain.’ Acid rain makes chemical weathering happen more quickly.
When acid rain reacts to the calcium carbonate in limestone new soluble substances are formed and when they are eventually washed away the rock is weathered.
Erosion:
Erosion is the process of removing the broken or loosened sediments to another place by water, wind, ice or gravity.
The Bruce Peninsula’s west side:
Here at the posted coordinates there is limestone rock. The continuous action of waves pounding against the limestone under the water breaks the rock down into particles of sand. But why is there rock here and not a sandy beach? The waves here travel parallel to the shoreline ~ the flowing current attacks the shoreline at an angle and is known as a long-shore current. This kind of current carries sand along depositing it further down the shoreline.
Here the limestone formation dips into the water exposing it to acidic water longer than if the shoreline wasn’t tilted therefore weathering the rock and minerals in the rock even faster. One theory suggests that the earth was under enormous pressure from the large heavy glacier suppressing the surface. When the glacier retreated, the crust rebound when the weight lifted and it slowly raised the land level over time. This is called glacial isostatic adjustment or isostatic uplift. Measurements of the Great Lakes show they are gradually tilting downward toward the south and west – on the east side of Lake Huron.
Photos of you in the area are always nice to see and add to the interest of the geocache page. Please consider adding some of your own.
Please DO NOT include photos that will give away any answers.
Favourite: If you like this Earthcache, please consider giving it a favourite point so others will know you enjoyed the experience. Thanks a bunch for visiting ~ Cedar & Co.