What You Will See Along the Trail - As you reach the back side of the lake, you will walk underneath cliffs over a hundred meters tall. The rock forming the cliffs is Gog quartzite which consists of quartz sand grains deposited in sediments millions years ago. Gog quartzite is classified as a “metamorphic” rock that has been transformed under intense pressure and heat from sandstone into quartzite. It is the hardest rock in the Canadian Rockies and is the underlying base for many of the mountains along the Icefields Parkway.
The reddish colors of the cliffs are caused by rusted iron rich layers. Passing beyond the quartzite cliffs, the trail runs along a delta formed at the west end of Lake Louise, where particles of silt carried in the meltwater streams settle when they reach the lake. When suspended in water these particles, known as rock flour, give Lake Louise its stunning color.
To reach the geocache site, you will follow the trail through subalpine forest and across several openings created by avalanche paths. Further up the path, you will have to cross a low cliff edge. Under the cliff is a moraine that you can traverse if you are not comfortable crossing over the ledge. Shortly after traversing the ledge, you will reach the geocache location where you have a beautiful unobstructed view of the valley and Lake Louise. Further up the trail you will have a birds-eye view of the Lower Victoria Glacier. This is all that remains of the massive glacier that existed during the Wisconsin Glaciation period – the last major advance of continental glaciers over North America that ended about 10,000 years ago.
Different Valley Types and How They are Formed - Valleys are one of the most common landforms on the surface of the planet. They are carved by flowing water or flowing ice through the process of erosion, which is the gradual wearing away of Earth surfaces through the action of wind and water. Valleys take on a wide variety of forms—from steep-sided canyons, such as the Grand Canyon, to broad plains, such as the lower Mississippi River valley. The shape of a valley depends on many factors, including what is eroding it, the slope of the land surface, the nature of the soil or rock where the valley is being created, and elapsed time.
A valley is a relatively large hollow or depression bounded by hills or mountains on Earth's surface that is developed by stream erosion or glacial activity and that is drained externally. Geologists refer to a body of running water moving downslope in a defined channel as a stream (a river is a large stream). A glacier is a large body of ice that formed on land by the compaction and recrystallization of snow, survives year to year, and shows some sign of movement downhill due to gravity.
There are two main types of mountain valleys - the “V-shaped” valley and the “U-shaped” valley. A V-shaped valley is a narrow valley that has a profile suggesting the form of the letter "V," characterized by steeply sloping sides. It results from a stream eroding downward, a process referred to as “downcutting”. V-shaped valleys form in mountains or other highland areas where streams are in their beginning or "youthful" stage and are flowing rapidly down steep slopes. The bottom of a valley is called its floor. In highland areas near a stream’s source, the valley sides slope down almost directly to the stream's banks, or sides of its channel. The valley floor in this region is narrow or even nonexistent.
A U-shaped valley is a valley that has a profile suggesting the form of the letter "U," characterized by steep sides that may curve inward at their bases and a broad, nearly flat floor. Specifically, a U-shaped valley is one carved by glacial erosion. Glaciers that form in high elevations near the tops of mountains are called alpine or mountain glaciers. Alpine glaciers flow down pre-existing V-shaped valleys created by streams to form U-shaped valleys. Because of this, they are also known as valley glaciers. Whereas a stream only occupies the floor (or a main portion of it) in a V-shaped valley, a valley glacier occupies the entire valley, eroding both the sides and the floor as it moves, deepening and widening the valley. U-shaped valleys are also known as glacial troughs.
Moving glaciers not only transport material as they move, they also sculpt and carve away the land beneath them. A glacier's weight, combined with its gradual movement, can drastically reshape the landscape. A valley glacier moves to lower elevations under the force of gravity through a combination of internal flow and sliding at its base. The ice in a glacier is so dense and under such pressure that it begins to behave like a thick tar, flowing outward and downward. Glacial movement through this internal flow is very slow.
In a valley glacier, ice in the upper central part moves faster than ice at the sides, where it is in contact with the valley walls. The considerable weight of a valley glacier also creates enormous pressure at its base, and this pressure lowers the temperature at which ice melts. A layer of water develops between the glacial ice and the ground. The water reduces friction by lubricating the ground and allowing the glacier to slide on its bed.
A valley glacier is capable of eroding and transporting huge amounts of sediment. As the glacier moves, its ice flows into and refreezes in fractures in the rock walls and floor of the valley. The glacier then plucks that rocky material away with it, some of which may be boulders the size of houses. This material then becomes embedded in the ice at the base and along the sides of the glacier. As the glacier continues to move, the embedded material abrades or scrapes the rock surrounding the glacier like a giant file. Following an existing V-shaped valley, a glacier erodes the valley, deepening and widening it. The glacier also flattens the valley floor because ice tends to cut down over a wider area than flowing water. When the glacier finally retreats, a thick layer of glacial sediment called ground moraine remains, filling in any irregularities in the valley floor.
A portion of the information above was taken from the following reference: http://www.scienceclarified.com/landforms/Ocean-Basins-to-Volcanoes/Valley.html
In order to receive credit for this earth geocache, please share your observations concerning the shape of the valley looking towards Lake Louise. Also, state what you think was the maximum extent of glacier that carved the valley in which you are standing. On what evidence do you base your answer? Although not required please consider posting a picture from this location (preferably of yourself or party), state whether or not you made it to the tea house at the Plain of Six Glaciers, and describe the weather conditions.
Answers should be emailed to: Andrew_and_Dad@rocketmail.com
Parks Canada’s mandate is to protect and present Canada’s natural and cultural heritage and offer exceptional visitor experiences. This earthcache has been approved by Parks Canada. www.parkscanada.gc.ca/banff