This cache is placed for the KACHE 5 Event. Held on Nov. 3rd. This cache is not to be found until the morning of the event date. Thank you for your cooperation.
WARNING: As part of offering this Earthcache: Be advised, This area does receive a lot of traffic and people should be careful of vehicles. Safely park on the shoulders and keep away from the roadway.
TO LOG THIS EARTHCACHE, Complete the following:
Take some pictures of your visit. If you wish, include them in your log. This is completely optional.
1. At the posted coordinates, Describe the evidence of mechanical weathering that is present. Observe and measure its width (the gap), estimate the height, and depth. Further, inspect the element and tell us if the rock surfaces within the gap is coarse, jagged or smooth to the touch. Also, describe the colors of the rock surface that is present. It is OK if the weather hampers efforts to identify colours.
2. At the posted coordinates, you will find a great example of a rock that has been split through the action of frost wedging. Do you see other examples of this type of weathering in the nearby rocks? If so, indicate the distance and direction that rock is away from the given example. Measure the widest gap between the two sections of the rock. While exploring GZ, do you see any other notable geological interests? Use 20m radius as a guideline. Email us your findings and explain if they occurred at the same time or if these have occurred individually over time? Pictures can also assist (but not required) in your answer.
Location
At this location you are looking for a large break in the bedrock through the rock cut that was removed for the development of Abey Dawn Rd. This is easily found in the vicinity of the posted coordinates. Sorry cachers, No Streetview of location! This formation has been here for several million years. Through urban expantion, and the development of roads, humans have altered this sheild bedrock for road ways. With rock being removed from the area, the weather and the sheer volume of the rock present on site have fostered perfect conditions for weathering minerals. Not all minerals or rocks are weathered identically. Climate plays a significant role, as such, in Canada and spefically in the Great Lakes St. Lawrence region, we witness frost buildup annually with many rock outcrops. Bedrock is not always solid. Bedrock in our region is subject to Karst topography and has many holes created through vertical erosion amongst the limestone bedrock. The bedrock on Abey Dawn Rd. does have gaps where air, minerals and water perculate through. Given time, and the right weather, enough rain buildup and cold temperatures will foster ice buildup. That ice in turn acts as a wedge between the faults, cracks, potholes, or gaps and over time, climate and physical forces, will create and enlarge gaps. This fosters the development of frost wedging. This is also know and identified as a form of Mechanical weathering.
What is Weathering ?
"Weathering is the alteration and breakdown of rock minerals and rock masses when they are exposed to the atmosphere. Weathering processes occur in situ, that is, in the same place, with no major movement of rock materials involved. Weathering is a fundamental Earth process. Weathering changes rocks from a hard state, to become much softer and weaker, making them more easily eroded."
In Canada, the most common form of Mechanical weathering is the annual onset of freezing ad thawing of water. Imagine a rock surface in Kingston's limestone region with gaps, holes, and typical karst topography. Annually, water freezes in those same locations. On Abey Dawn Rd, we witness this same effect and can see in the winter months when and where water freezes. This identifies that there evidence of cracks, faults, gaps and holes within the bedrock sufficient for water to perculate then expand as it freezes. As we all know, as water freezers, it enlarges. Look at a frozen icecube before/after it sets in your freezer. As we endure winter in Kingston, the rock surface will be subject to expansion. When spring returns, the ice melts in the expanded spaces and causes some surfaces, and the following winter will recreate the same pattern and continue its expansion of the surface area.
For additional information of Physical and Chemical weathering, please visit - Here.
Reference Material: Hong Kong Geology - A 400-Million Year Journey. http://hkss.cedd.gov.hk/hkss/eng/education/GS/eng/hkg/chapter4.htm
GeoKids.com - Geology for Kids: Mechanical Weathering. http://www.kidsgeo.com/geology-for-kids/0066-mechanical-weathering.php
Kingston Annual Weather Information