The world famous Burgess Shale Slope offers a visually stunning hike that pays off with a teeming selection of rare invertebrate fossils, sealed into the geological timeline by an underwater avalanche of fine mud
By Alan King
FIELD, B.C, — Science fiction writer H G Wells didn’t know the half of it. Time travel sometimes takes more than imagination and clever engineering; it can take a lot of nimble, arduous footwork, the kind that gets you up to 7,500 feet above sea level.
Unlike Wells’ lucky Time Traveller who was effortlessly transported millions of years into the future where he met some strange life forms, my son Christopher and I went back half a billion years in the other direction to the Burgess Shale — an ancient fossil bed where the life forms are even stranger. Its location is a swath of scree 11 km up the side of Mount Wapta, a spectacular hunk of geology looming majestically over Field, British Columbia.
The fossils here are from the Cambrian Explosion, an era that began 542 million years ago when simple life in the sea erupted into a huge array of species, all of them vastly larger and weirder than anything that had come before. It was an extraordinary event in the earth’s history but what made it so unusual was that it was mostly soft-bodied creatures — squids, worms and cactus-like sponges — that ended up as fossils, not the usual specimens with hard shells and skeletons.
They were buried in an underwater avalanche of fine mud that sealed and preserved them, so well in some cases that their inner organs are clearly visible. The mudslide took these aquatic bizarreries by surprise as they swam along the continental shelf and today, amazingly, they reside a mile and a half above sea level.
How they got there is no secret. Continental drift and plate tectonics did their slow-motion bump and grind, eventually pushing them heavenward.
But the question of why this diverse menagerie suddenly blossomed is still a subject of intense scientific debate. One thing is certain: it’s a very big deal in evolutionary history. There isn’t a biologist or palaeontologist anywhere who doesn’t know about it and isn’t mystified by it.
Discovered in 1909 by the Smithsonian director Charles Walcott while exploring on horseback (no hiking for him) it has become a mecca for geologists and palaeontologists from around the world, not just for its scientific importance but because the view from the site — as well as the hike — leaves one breathless.
At the bottom of the valley lies famous Emerald Lake, whose water is so turquoise and luminous it looks like a CGI-enhanced illusion. Across the valley at eye level sparkles the glacier of Michael Peak with an outlet stream plunging into a series of astonishing cataracts.
Along the way our walk is punctuated with stops for brief lectures by Annie, our guide from the Burgess Shale Geoscience Foundation (access to the site is restricted to those on guided tours). She riffs excitedly about the history of the planet, mountain building, plate tectonics, the discovery of the site and the life forms we can expect to see. And mercifully, once in a while she lets us stop to soak our feet in a cold, crystalline lake.
The last killer kilometre is a series of steep switchbacks — the kind that make you wonder if you’ll at any moment be obliged to carry that other overweight fellow trekker down on your back — but it’s worth the effort. There are fossils underfoot everywhere.
Trilobites – those creatures that look like big, aquatic cockroaches — are the easiest to spot. You can also find the wonderful marella, another arthopod with two elegant, swooping appendages that resemble the hood ornament on a ’60s Cadillac. If you’re very lucky you might even see the bizarre and appropriately named hallucigenia. This guy sports a worm-like body with seven pairs of legs and an equal number of long spines running along its back — part garden hose, part porcupine.
If you can’t find the precise critter you’re looking for, Annie hauls prize samples out of a permanent steel cabinet, all carefully labeled. Not that everyone needs her help. The rest of the group includes a brain trust of geologists and academics who wear their knowledge as lightly as their knapsacks and happily explain who ate whom, who didn’t make the evolutionary cut and who is still around lurking in the ocean today.
As it began so it ends, with a long, exhilarating trek down to the parking lot across from Takakkaw Falls, (‘it is magnificent’ in Cree) at 300 metres one of the highest waterfalls in Canada. This glacial stream bursts from the cliff face as if it has been fired from a water-cannon, turning into a misty rainbow near the bottom. Magnificent indeed.
Exhausted and hungry we head for dinner and a glass of wine at a restaurant in Field to ponder the origins of complex life and to toast the indisputable fact that some its secrets are revealed at one of the most beautiful places on earth.
THE EX-PRESS, December 5, 2015