This Earthcache will bring you to Benmiller falls, on the Maitland River - The Maitland river drops over a Limestone ledge, which will disappear entirely during high water levels of spring melt. The Ledge is just over 200 meters long, and during the summer months can be walked along. You can approach this area using the Maitland river trail from Benmiller , or purchase a day pass with the Falls Reserve Conservation area and park nearby.
The Ridge itself lies on Devonian rocks some 400 million years old that lie in a broad belt extending across southwestern Ontario from central Lake Erie to Lake Huron. These rocks also underlie part of the Windsor-Essex area and form the bedrock of Pelee Island. The texture and fossils in the rocks suggest the limestones originated as lime muds with brief conditions of active bottom currents.
Eighteen thousand years ago most of Southern Ontario was covered with a massive ice sheet. During the retreat of the Wisconsin Icesheet, the wasting glacier broke into several lobes. The Huron Lobe filled the basin of Lake Huron and had most influence on the surficial geology of the Maitland River and surrounding areas. About thirteen thousand years ago Lake Whittlesey covered the entire Lake Erie basin as well much of southwestern Ontario. About this time the melting edge of the Huron Lobe built the Wyoming Moraine, a ridge of land which runs parallel to the shore of Lake Huron but several kilometers inland from the current shoreline. Melt water running off the icesheet formed a well-developed spillway along the front of the moraine. The spillway entered Lake Whittlesey at the location of Hensell. The Maitland River runs in this ancient spillway, and from Auburn to Benmiller, a straight distance of some 15 km, it meanders south along the spillway almost as far as Homesville before finding a break in an outlying section of the Wyoming Moraine and travelling north again (a distance of about 54 km). At Benmiller, the river breaks through the main moraine in a deeply incised valley that has cut through to the underlying bedrock. The river then continues in a meandering valley to its mouth at Goderich. The process of rapid down cutting during the period when the Lake Huron shore was rebounding after the ice was removed, has left a series of terraces, slopes and meander scars in the sides of the valley.
As the river passes through the Wyoming Moraine west of Benmiller, there are steep valley slopes and bottomland terraces. Tributary ravines are spectacularly narrow and steep-sided; a result of rapid down cutting by streams as they reach the level of the main river. At the outside of bends, the river is actively undercutting the valley walls. Here the valley slopes are steep and often actively eroding. At the base of the slopes, ice scouring keeps the exposed limestone bedrock relatively free of soil and vegetation. At the inside of river meanders, deposits of gravel and cobbles form bars and swales. There is often a substantial bottomland between the river and the valley wall, and often fine examples of meander scars well above the present level of the river.
To Log this cache, answer the following WITH YOUR LOG:
1) Approximate height difference in water level above the falls to below the falls?
2) What approximate percentage of ridge is covered in water, and what is bare rock?
3) A unique Picture of the falls, and yourself if you are so bold!