Pinnacle Rock and Layer Cake Mountain - Looking up from Gallagher's Canyon:

This view of Pinnackle Rock and Layer Cake Mountain is attainable after a brisk walk down a trail in Scenic Canyon Regional Park. Take KLO road east from Pandosy or Gordon Drive to McCulloch Road. Follow McCulloch road to Field Road, then turn to the north, following Field Road to its end. Park in the parking lot, then hit the trail down into Gallagher's Canyon about 2 km till the trail branches near Mission Creek. I followed Mission creek along a narrow, makeshift trail untill I got to the base of Layer Cake Mountain. Seeing a picture is one thing, but being in the presence of this natural beauty is awesome.

Layer Cake Hill, sometimes called Layer Cake Mountain, is a volcanic land form composed primarily of Dacite [day-site] (volcanic rock with a high iron content). It shows unique layering that has not been seen anywhere else.

Layering is expressed as thin layers separated by thick layers exposed along a weathered fault scarp. The compositions of the thick and thin layers are geochemically very similar. The thin layers represent veins generated during crystallization of the lava. The thin layers formed when the molten material contracted (shrunk) while cooling. Material was allowed to flow into the cracks formed by cooling. The material in the cracks further fractured when it cooled, and liquid material was allowed to enter the veins. The resulting rock was formed with a slightly different composition. The altered thin layers weather faster, thus visually showing the small primary chemical differences between thick and thin layers.

Approximately 50 million years ago, volcanoes erupted in the Kelowna area and along the Okanagan Valley. Since that time, erosion by large streams removed much of the volcanic bedrock, carving a broad deep valley along where Mission Creek now flows. The Ice Age eroded and carved the land by several glaciers during different times in the last one to two million years.

The last of these glaciers started to advance about 25,000 years ago and filled the valley higher than any of the mountains of the Okanagan today. It began to melt away about 15,000 years ago and finally disappeared about 10,000 years ago.

As the Glacier melted in the Mission Creek Valley, the valley was blocked or dammed for some time by large blocks of ice and debris in Gallagher's Canyon. Material deposited from the ice served to partly infill the ancient valley. But lots of ice remained and the ice was still melting. This produced a lot of water. The water could not escape because of the ice dam in the canyon. Therefore, a large lake was formed along the upstream part of Mission Creek Valley. The flat topped terraces along the present valley sides were on the bottom of this ancient lake.

Water built up in the glacial lake behind the ice dam and finally the dam burst about 10,000 years ago, and a catastrophic flood occurred. All of this rushing and turbulent water was responsible for cutting a steep-sided gorge along the face of Layer Cake and eroding what we now call Gallagher's Canyon. One side (the north side) of this gorge was the steep face of Layer Cake Hill. The south side does not show this erosion effect because it was still covered with a thick layer of ice and debris.

During this time when the lake was being drained at a very high rate, high flows of melt water were also arriving here from the KLO Creek valley. The combination of these water flows must have created a huge whirlpool that swirled around carving out a portion of Layer Cake Hill and finally forming a pinnacle of rock that we call the "Pinnacle" today.

From Mission Creek - East Kelowna BC - September 14, 2009.