By: Alan V. Morgan
If you are a person interested in geoscience education, August 2003 was the month to be in Calgary. The meeting was hosted by the Canadian Geoscience Education Network a standing committee of the Canadian Geoscience Council, but run by a small group of local volunteers over four days of meetings preceded and followed by some fantastic fieldtrips.
Over 280 delegates from across Canada and around the world met at the University of Calgary at the fourth meeting of the International Geoscience Education Organisation (IGEO). The meeting welcomed guests from 27 different countries and was generously subsidised by Encana and a variety of other sponsors. The participants had three complete days of educational presentations and a stimulating visit to the Royal Tyrell Museum of Paleontology at Drumheller. There were also educational workshops and a complete suite of field excursions. During the meeting keynote lectures were given on the Geology of the Rockies, Paleolimnology, Gros Morne Park, Newfoundland, and the Chicxulub impact and the demise of the dinosaurs. In this and in a subsequent section I would like to describe two of the field trips that I attended. Choosing field trips was a major task since they were all fascinating and run by experts under great weather conditions. I eventually decided that the Burgess Shale locality and a visit to a dinosaur excavation site would personally be most valuable.
Burgess shale
Day one of the conference and thirty eager participants gathered at 7:00 a.m. to board a bus to head just west of the Alberta border to Field in BC. The two and one-half hour journey passed with a running expose of the unfolding geology as we passed from the Quaternary surfaces near Calgary, through the Foothills belt and past the McConnell Thrust into the Front Ranges of the Rockies. By 9:30 we arrived at our jumping off spot at Takakkaw Falls in Yoho Park.
We had been warned in no uncertain terms about the rigours of the hike from the parking lot to the outcrop and back. This was a round trip of approximately 20 km with a vertical climb of half the height of the Grand Canyon. The first and last parts of the hike were certainly the worst with interminable switchbacks that seemingly only took you a few tens of metres higher up the slope. However, if the walking was strenuous the scenery and the companionship made the going a lot easier. Our group consisted of delegates from as far away as Europe, Japan and Australia. A few, including Jon Dudley, Randle Robertson and Dave Rudkin had visited the exposure many times, but others including myself, had either known the exposure by infamy or gazed upon it from far below at Emerald Lake.
The views along the way were spectacular and I have illustrated a few of these on the accompanying colour page. When we finally reached the quarry we were given an excellent overview by Jon Dudley (left) who provided background information on this 1972 UNESCO designated World Heritage site that is also within a 1984 UNESCO World Heritage Park! He provided us with the background of the discovery and the fate of the specimens gathered by Walcott almost a century ago (mostly all in the US National Museum). He also commented on the success of the Geological Survey of Canada who re-opened the exposure in 1966 and the subsequent excavations by several museums (principally the Royal Ontario Museum and the Royal Tyrrell Museum of Palaeontology) at the site. In the interim various members of the party had been scouring the quarry for fossil-bearing slabs. It didn't take the group long to collect fragmentary and whole representatives of some of the fossils that had turned up over the years. These included Marrella splendens (below, top left); a 7 mm long trilobite called Ptychagnostus (below, top right), an Anomalocaris grasping mouthpart (bottom left) and many others. On the bottom right, I have illustrated a reconstruction of what Anomalocaris might have looked like in life. This large arthropod is an excellent example of how continuing excavation and research has revealed a hitherto unexpectedly large Cambrian predator. Parts of Anomalocaris were originally discovered by Walcott who described the mouth as a jellyfish and the "grasping" claws as a large shrimp. Decades later individual fragments were recognised as part of the same animal, suggested as a trilobite predator that was up to 50cm in length!
Eventually after an all-to-quick several hours we had to leave this fascinating glimpse of a 505 million year old window in time and return to the present. The fossils were returned to their resting places in the quarry and we walked back down along the Cathedral Limestone escarpment. These rocks had played an important role, perhaps in the creation of the fossil bearing beds as soft bodied organisms were carried off the top of this formerly marine slope into deeper water, and later in protecting the specimens from the regional greenschist facies metamorphism. Hours later we were safely back in Calgary and I was thinking of my next field trip - this time into a far younger part of the geological column. I was about to go dinosaur hunting!