This earthcache focuses on the high amount of sediment that is deposited at this location in the Credit River, probably the most than anywhere along the section of river stretching from Caledon down to Lake Ontario. Here you will find the confluence to 2 rivers, where Silver Creek feeds into the Credit River. Easy and nearby access to the Credit River and this Earthcache can be obtained from Willow Park Ecology Centre in Norval or by floating down the Credit River from several kms upstream. You can't float past the dam nor access the river from the dam as the dam is private property. As you walk out into the Credit River, step carefully as you may feel yourself starting to sink within the sediment. You may want to bring some kind of flotation device like a tube to hold onto while you move around the river. There is little flow here due to the dam being just a bit down stream. Your task is to examine the Sediment deposits on the river floor and the area around it. Bring a container with you to help you complete the logging requirements.
Sediment is a collection of small particles, particularly dirt, that precipitates from a river or other body of water. Silt is a type of sediment and is mud or fine earth deposited from running or standing water.
SEDIMENT
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation. If buried, they may eventually become sandstone and siltstone (sedimentary rocks) through lithification. Lithification is the process by which unconsolidated materials are converted into coherent solid rock, as by compaction or cementation.
Sediments are most often transported by water (fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments.
SILT
Silt is granular dust-like sediment material of a size between sand and clay, whose mineral origin is quartz and feldspar. Individual silt particles are so small that they are difficult to see. To be classified as silt, a particle must be less than .005 centimeters (.002 inches) across. Silt is found in soil, along with other types of sediment such as clay, sand, and gravel. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water (also known as a suspended load) and soil in a body of water such as a river. It may also exist as soil deposited at the bottom of a water body, like mudflows from landslides. Silt has a moderate specific area with a typically non-sticky, plastic feel. Silt usually has a floury feel when dry, and a slippery feel when wet. Silt can be visually observed with a hand lens, exhibiting a sparkly appearance. It also can be felt by the tongue as granular when placed on the front teeth (even when mixed with clay particles).
Please submit your answers to me for the following Earthcache logging tasks.
1) Go into the river and take a sample of the particles at your feet. What do the sediments feel like? Smooth or gritty?
2) Collect and transport the samples you have taken (you may want to bring a container with you). Take these home and let them dry out and explain what these sediments look and feel like and the range of size of them.
3) Do you believe there is any silt within the sediment?
4) How deep is the deepest of the deposits that you found in the river, within about 20 meters of the posted coordinates...you can either stand in it or use a stick. If you choose to stand, maybe for safety reasons you have some kind of assistance either from a buddy or a flotation device. I wouldn't want you to get stuck.
5) Go to the edge of the sediment deposits where the ground at your feet becomes solid and you don't sink, which will be out from the shore and downstream a bit. What is the material at your feet?
6) From your observation of the area, what factors do you believe lead to the accumulation of sediments at this specific location?