The View from Castle Rock

used to a certain way of reckoning history.
    A glacial landscape such as this is vulnerable. Many of its various contours are made up of gravel, and gravel is easy to get at, easy to scoop out, and always in demand. That’s the material that makes these back roads passable-gravel from the chewed-up hills, the plundered terraces, that have been turned into holes in the land. And it’s a way for farmers to get hold of some cash. One of my earliest memories is of the summer my father sold off the gravel on our river flats, and we had the excitement of the trucks going past all day, as well as the importance of the sign at our gate.
Children Playing.
That was
us.
Then when the trucks were gone, the gravel removed, there was the novelty of pits and hollows that held, almost into the summer, the remains of the spring floods. Such hollows will eventually grow clumps of tough flowering weeds, then grass and bushes.
    In the big gravel pits you see hills turned into hollows, as if a part of the landscape had managed, in a haphazard way, to turn itself inside out. And little lakes ripple where before there were only terraces or river flats. The steep sides of the hollows grow lush, in time, bumpy with greenery. But the tracks of the glacier are gone for good.
    So you have to keep checking, taking in the changes, seeing things while they last.
    We have special maps that we travel with. They are maps sold to accompany a book called
The Physiography of Southern Ontario,
by Lyman Chapman and Donald Putnam-whom we refer to, familiarly but somewhat reverentially, as Put and Chap. These maps show the usual roads and towns and rivers, but they show other things as well-things that were a complete surprise to me when I first saw them.
    Look at just one map-a section of southern Ontario south of Georgian Bay. Roads. Towns and rivers appear, as well as township boundaries. But look what else-patches of bright yellow, fresh green, battleship gray, and a darker mud gray, and a very pale gray, and splotches or stretches or fat or skinny tails of blue and tan and orange and rosy pink and purple and burgundy brown. Clusters of freckles. Ribbons of green like grass snakes. Narrow fluttery strokes from a red pen.
    What is all this?
    The yellow color shows sand, not along the lakeshore but collected inland, often bordering a swamp or a long-gone lake. The freckles are not round but lozenge-shaped, and they appear in the landscape like partly buried eggs, with the blunt end against the flow of the ice. These are drumlins-thickly packed in some places, sparse in others. Some qualifying as big smooth hills, some barely breaking through the ground. They give their name to the soil in which they appear (drumlinized till-tan) and to the somewhat rougher soil which has none of them in it (undrumlinized till-battleship gray). The glacier in fact did lay them down like eggs, neatly and economically getting rid of material that it had picked up in its bulldozing advance. And where it didn’t manage this, the ground is naturally rougher.
    The purple tails are end moraines. They show where the ice halted on its long retreat, putting down a ridge of rubble at its edge. The vivid green strokes are eskers, and they are the easiest of all features to recognize, when you’re looking through the car window. Miniature mountain ranges, dragons’ backs-they show the route of the rivers that tunnelled under the ice, at right angles to its front. Torrents loaded with gravel, which they discharged as they went. Usually there will be a little mild-mannered creek, running along beside an esker-a direct descendant of that ancient battering river.
    The orange color is for spillways, the huge channels that carried off the meltwater. And the dark gray shows the swamps that have developed in the spillways and are still there. Blue shows the clay soil, where the ice water was trapped in lakes. These places are flat but not smooth and there is something sour and lumpy about clay fields. Heavy soil, coarse grass, poor drainage.
    Meadow green is for the bevelled till, the wonderfully smooth surface that the old Lake Warren planed in the deposits along the shore of today’s Lake Huron.
    Red strokes and red interrupted lines that appear on the bevelled till, or on the sand nearby, are remnants of bluffs and the abandoned beaches of those ancestors of the Great Lakes, whose outlines are discernible now only by a gentle lift of the land. Such prosaic, modern,