Rock solid. Something we can totally count on. Like the bedrock under our feet. Unmoveable like a mountain. Unchanging like the granite boulder in the field, in our yard. In our culture, rocks are an image of what we can depend on, strength that does not change.

I've been walking up the escarpment on nice days. Part way up the hill, cedar trees spread their roots across a slab of rock, reaching for soil, digging in to the uphill edge. The downhill edge is undercut, creating a hollow. Perhaps streams of rain water dragged away the earth under the rock. Likely water seeped into small pockets, froze and expanded, cracking the hard stone, breaking away layers of rock.

Further along, slabs reach out across a gurgling stream. In these, horizontal cracks create a layer that looks like it is about to break away. The rock ledge is precarious. How much weight would it bear?

Back home, along the shore are rocks of many different shapes. There are small slabs of limestone that were broken off ledges like the one beside the creek. Some of these have rough edges so that if you found the place it came from it would fit like a jigsaw puzzle piece. Some have rounded edges from their time in the water.

Small flat skipping stones are prevalent. These have been smoothed by rubbing against each other with waves washing over them. At times, beside the larger stones, there are small, smooth pebbles that have spend ages under the waves, along the shore, changed by the water.

The mix of rocks on the shore changes. Heavy surf pulls the small rocks away, heaves up new slabs. Gentler waves bring back the pebbles. I thought when I moved here that I would have to impose a limit of how many stones each person could skip, but it turns out that the waves retrieve them for us.

Also on the shore are fossils of what look like sea creatures, some like scallops, some long ridged creatures. Turns out that these are really old, from a time before the dinosaurs. These small creatures lived in a world very different from our own. At the end of their life, they fell into sediment that was pressed down, becoming rocks that preserved the memory and shape of their life. What looks like a hard stone on our shore was once sand and muck and a living creature.

Geologists tell us the story of rocks. We see a sparkling diamond held in a band of gold. The gold is a mineral dredged up out of the earth, but the stone is carbon, was once living material. Diamonds are life transmuted into stone. So is amber, among others.

Watching the power of a storm on the shore, it is not so surprising that rocks get moved. But on our farm, in the wooded area at the edge of the escarpment, there were granite boulders as big as a Volkswagen beetle. These belong to the shield in eastern Ontario.

During the last ice age, the glaciers broke this granite away from the land it was part of, rolled it and smoothed it, carried it hundreds of kilometers. As the ice melted, the rock moved more slowly. Eventually, five bounders were dumped over the lip of a small ravine. There they rest because no force remained to carry them up the hill on the other side.

Similar bounders had been left in the middle of fields. We brought in heavy equipment to dig them out and move them to the edge of the field where we would not have to go around them or break equipment on the ones with just a nose sticking up. There was a place, though, where a plow running deep would catch an edge of bedrock. That we could not move. The plough had to give.

There is rock underneath us, a solid foundation to build on, to stand on. There is rock above us when we stand beneath escarpment cliffs, majestic and enduring. Stones are strong as hammers. Diamonds are cutting sharp.

But rock has life, though it may be shaped over millions of years. Rocks are not unchanging. Other things that we depend upon are only as enduring as a rock that water will smooth, ice will crack, time will shift to something unrecognizable.

Cathy Hird lives on the rocky shore of Georgian Bay sheltered by the escarpment