My Observations On The School Yard

On Sunday September 20th The class of Geog 2020 went on a field trip to observe bio-physical features of the Ottawa area. Our first stop was to Erskine Johnson Elementary School in Kanata where there is a large visible outcrop of precambrian rock in the school yard. Our next stop was to The March Highlands Conservation Forest, a forested area that features beaver ponds and sand stone beddings. Next we moved on to the Crozier pit, a mining sight near Renfrew that features a large precambrian marble outcrop and deep pit with visible sediment layers on a the outside ridge. Our last stop was the Fourth Chute of the Bonnechere river which is the site of the Bonnechere Caves. Before going into the caves my group investigated the fossil covered rocks down by the by rapids of the Bonnechere river. And then we went on our guided tour of the beautiful limestone Bonnechere Caves. In this paper I will explain and elaborate on my observations.

In the school yard of Erkine Johnsons Public school there is a large outcrop of precambrian metamorphic gneiss. This rock has been heavily weathered over millions of years, to the point were non of the glacial striations are visible on the surface of the rock. Metamorphic foliations within the rock have not weather and are visible. It is a coarse grained rock as can be seen in figure 1. Throughout the rock outcrop there are three different generations of ingenious dykes that crisscross the surface (see figure 2). There are three different types of rock forming dykes throughout the exposed gneiss, diorite, apilite and pegmatite. Dark coloured dykes are diorite, a fined grained rock that weathers more quickly then the gneiss as observed by the trenches created along the dykes illustrated in figure 3. Als...

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...o pressure. Eddies have created rooms large enough for several people to stand in. On the walls of the cave you can see different layers of of the sedimentary limestone with a wavy patterns. Within some of the layers there are some fossils to be seen. The roof and the walls of the cave slowly leach water. This water carries particles of calcium carbonate, when the water drips this calcium carbonate is left behind and slowly as these particles build up creating icicle like features called stalactites. The inside of the cave is not a very good habitat for most animals without the man made lights it is dark and cold however bats who prefer dark places have taken up residence in the caves. There numbers however, are not what they once were when the caves were first explored by Tom Woodward in 1955 (figure 23)

Figure 22: Wet and wavy texture of the Bonnechere cave walls.