Howard Donohue’s warm personality was most welcome this past Sunday. It was a chilly day at Point Pleasant Park, both on Sunday, November 24, 2013, and 10,000 years ago!
Howard is a geologist, having fallen in love with the wonderful world of rocks way back when we was in Grade 9. His enthusiasm hasn’t waned over the years – he got everyone on the trip excited to “listen” to what the rocks of Point Pleasant Park had to say. The sea and the rocks have been interacting at Point Pleasant Park for a long, long time. Back about 10,000 years ago, right where we were standing, would have been covered by 1 to 2 km of ice! This was the most recent glaciation event in the region, and as the glaciers retreated, they pulled rocks across the bedrock of the park. Howard showed us a spot where you can see striations from rocks that were being pulled along during the glaciers’ retreat. The glaciers’ retreat was not all in one go – it was dynamic, with pulses forward and backward. As the glaciers melted, the pressure they exerted on the land beneath them began to ease up, and the land started to “bounce back.” At the same time, the melting glaciers were emptying water into the sea, causing it to rise. Both these processes are still, slowly, happening today.Howard “borrowed” a couple of Young Naturalists to help act out the processes for our group.
Wave action is also, slowly, effecting rocks at the park. As stones are tossed up onto the shore, again and again, they become smooth and rounded. We all examined some of the stones on the shore, and found things like rounded sedimentary stones, and rounded ashpalt and bricks!
Howard did a great job answering our many geology questions, and keeping the group moving and happy on such a cold day. We all came away from the field trip with a better understanding of the glacial history of the park, and with a few rocks in our pockets.
Make sure to check out a couple photos, and a video, from our field trip in the Photos section of the website.