Glaciers are rivers of ice. The solid water phase may pick up mineral debris, which can abrade surfaces in contact. This earthcache demonstrates the erosional power of glaciers to carve the landscape. During the last ice age a glacier covered this location. The slowly sliding ice left many rock surface features showing contact abrasion.
At the listed coordinates in downtown Victoria you can see a bedrock surface exposed since glaciers retreated some 10,000 years ago. The rock surface shows distinct evidence of glacial erosion. Glacial damage gives geologists information about the direction that the ancient glacier moved. The path of the glacier’s movement is parallel to the long direction of the glacial damage.
Glacial grooves are created beneath a glacier. The grooves were created by the slow movement of the massive glacier. As glaciers move, or flow, across the land, they pick up pieces of rock. The trapped material is dragged along the surface of the rocks beneath the ice. Rock fragments act like sandpaper and abrade the bedrock as the glacier drags them along. Abrasion will gouge out softer rock beneath the glacier to form the grooves. The groove features are exposed when the glacier melts.
Visit the listed coordinates of this Earthcache, examine the exposed rock, and please answer the following questions. You may log your find immediately. Do not forget to send your answers to the cache owner by email or message.
1. Use a compass to determine the direction of glacier travel. You will have a compass in your GPSr or smart phone.
2. What is width and depth of the deepest groove?
3. Within a couple of metres of the rectangular metal plaque is a man made feature in the rock. Please describe?
