Heritage: Pre-Historic Swansea

During a Swansea Historical Society meeting on 4-February-2009, George Duncan held a fossil he found along the Humber River

TORONTO, ONTARIO - The Swansea Historical Society held its first regular meeting of 2009 on Wednesday, with the George Duncan as the featured speaker. Duncan took his audience back to a much older time than in most meetings--445 million years ago.

How is that? Those who have walked along the Humber River, in particular those areas with cliffs like Bâby Point north of Swansea, may have noted that very distinct layers may be seen in the soil. These formations are layers of sedimentary rock, the kind of formation where one can find fossils, and this presentation was about fossils.


George Duncan held up a shell at the Swansea Historical Society on 4-February-2009, demonstrating the kind of object that most easily fossilizes

Fossils will not form in just any conditions. The dead plant or animal must be isolated from oxygen and normal methods of degradation, usually through burial, and some sort of preservation process must occur, mostly commonly petrification, the slow replacement of cells with minerals. Sedimentary rock combined with some sort of disruption burying the lifeforms is one scenario that can fossil formation. Furthermore, it is the hard portions of the life form, such as a shell or tooth, that tends to last long enough to be fossilized, not the soft portions that decay much more easily.

Appropriate conditions to form fossils were in place in what is now Swansea and greater Toronto 445 million years ago during the Paleozoic era. At that time, the continents were in a completely different position, and this area was only about 20 degrees above the equator and was underwater. Thus, the lifeforms present were the sub-tropical undersea creatures (only a few plants had managed to grow on land in any event), such as trilobites and nautiloids. Small nautiloids are the most common fossils found along the Humber River and Mimico Creek.


George Duncan showed a larger piece of rock containing fossilized tracks of an ancient life form at a Swansea Historical Society Meeting on 4-February-2009

While other epochs are represented in fossils found in other areas of southern Ontario, everyone's favorite kind of fossil--dinosaurs--are not found here. They are found in Canada, though, as some of the most significant dinosaur remains ever found have come from Alberta.

Of course, considering the average age of a historical society member, the most common joke of the night was whether there were any fossils in the audience. After being educated in the formation of fossils by George Duncan, we could rest assured that there were no fossils observing his presentation.