Thanks to everyone who joined us for a lovely outing to the Doris McCarthy Trail. Vannessa brought her Dad’s wonderful fossils, collected from all over Ontario. A special thanks to Geologist Ed Freeman, who explained that these creatures once lived in a shallow tropical sea that covered Ontario when it was at the equator! Some of these creatures were similar to animals that might be found in the Caribbean today. We learned about sedimentary rocks and found some shale in the creek bed on the way down the trail to the lake. There were also four hawks circling around overhead, two Redtails, a Coopers and one unidentified.
At the lake we scrambled out on the promontory, and enjoyed a spectacular view of the Buffs looking landward. Ed filled us in on the history of the Scarborough Bluffs. They are sediments deposited at the delta of a great pre-glacial river that flowed south into an ancient lake. This lake was ice-dammed, cold and deep. We could see two layers. The lower layer was lighter colored and it is covered by a thick grey layer. This deep cold lake persisted till an ice sheet thickened and covered all of Ontario and the northern US about 20,000 years ago.
We searched for fossils on the great slabs of 450 million year old Silurian limestone. These slabs of rock were brought to this location from the Niagara escarpment to harden the shoreline and stop erosion of the Bluffs. We found crinoid stems, tabulate coral, and large circular shapes in the rock that we thought might be stromatoporoids. We used hammers to split open some rock, and made our own fossils of leaves, and rocks, etc. using plaster of Paris.
- Get the story of Gates Gully and the Doris McCarthy Trail
- Get it all figured out about Ontario Natural history
- Go bigger at the Royal Ontario Museum
- Travel around the province to amazing Geological sites using this book by Nick Eyles as a guide: Road Rocks Ontario
- Read about Gates Gully in Toronto’s Ravines and Urban Forests (Chapter 5) by our own TFN president, Jason Ramsay-Brown