10. Gneiss (Jesse’s rock)

Deep under a mountain range I was a part of a great mass of granite. I started my second rock cycle as molten magma, which gradually cooled over millions of years. When the mountains of which I was part of were eroded by wind and rain, my tiny particles became mud and sand. My quartz crystals were ground down and formed sand. This sand was just like the sand you play with on the beach in the summer.

The other minerals, feldspar and mica in my granite were ground and decomposed into fine mud and clay. These materials were transported from the north west of Ontario to a growing river delta. A great wedge of sand, gravel, silt and clay grew. As more layers were deposited on the top of my eroded material, water was squeezed out of the mud and sand. Over time sand turned to sandstone and silt and clay turned into siltstone and shale.

More mud was added to the pile and time moved on. Two continents moved together pushing thousands of metres of rock into a stack of layers 10,000 metres high or more. Some of the beds were flipped upside down as they rode over each other.

The rocks at the bottom of the pile including the remains of my granite, moved ever deeper to about 25 kilometres below the mountains. It was very hot down there. The rocks became squishy, and moved slowly. The layers of sandstone and shale gradually heated up. Shale turned to slate and then changed to sparkly mica flakes. Sandstone hardened into quartzite. All this material then flowed slowly and folded without melting.

Cracks opened up in the rocks and the mineral quartz crystallized in the cracks.

Half a billion years of erosion washed away the mountains forming other rocks. My new crystals were then exposed to the atmosphere again. I saw interesting things happening for 500 million years. Living things moved across the surface of the Earth and flew in the sky. Ice scrubbed my surface a few thousand years ago, during the Ice Age. Recently humans found my sparkles irresistible, cracking out lumps of my rock to decorate their homes and gardens. To break the rocks from the ground, holes are drilled into me using a drill bit covered with a hard mineral called diamond. You can see some of the holes in Jesse’s rock drilled so my rock could be free from the surrounding ones at Red Bridge, near North Bay, Ontario.

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Jesse found rock stories exciting. As a boy he used to collect rocks and imagined all the interesting stories they could tell.

When Jesse grew up his interest in rocks became his career. He worked as a hydrogeological technician in the Department of Earth Science at the University of Waterloo then later became an environmental driller for Geo-Environmental Drilling Company. In order to read the messages in the rock, Jesse drilled into mud and sand deposited during the Ice Age.

He did this to find useful things for people, such as groundwater and sources of pollution, which needed cleaning up.

Jesse’s rock is here to remind you that we all have a life cycle. We touch other people’s lives transforming them in wonderful ways which continue when we let go of the material forming our bodies. This material continues on through Planet Earth’s cycles of life, water, and rock. Given enough time a part of you may find it’s way into a sparkly mineral like diamond or mica. What an adventure!