[MUSIC] Glance at any atlas or map of the world that exhibits relief, and it becomes quickly apparent that mountains are nearly everywhere. Mountains occur in three quarters of the world's countries. Mountains can be found on every continent. They can be found in every climate and they can even be found in every ocean. But have you ever considered why mountains are located specifically where they are? How did they get there? In this lesson, we'll explore the physical origins of mountains, theories of mountain building, and how changing ideas of mountains and their genesis have shaped our engagement with them. Societies have interacted with the heights for countless millennia and mountain origin stories are numerous around the globe. Each is valid in its own respective cultural context, and each has important insights to offer. In this lesson, we focus generally on one particular origin story. An origin story born here in the West, which would lay the foundation for the science of geology. We hope this focus will give some context to the science of mountain building. Our story begins with the consideration of time, or perhaps the lack thereof. It wasn't so long ago that popular ideas about the origins of mountains completely lacked that fourth dimension. And it's not that surprising when you think about it. What can be more permanent, more undeniably there than a mountain? For centuries, among the Western intellectuals it was believed that mountains had been cast in their present poses by God, and would remain always and forever that way. Prior to the 1700s for many people in the West it was the Christian Bible, specifically the biblical account creation that really determined how the Earth's past was imagined. And according to the Bible the beginning of the world was relatively recent event. Based on the information set down in the Bible, several early scholars had attempted to calculate a beginning date for the planet. And of those, the best known was James Ussher, the Irish Archbishop of Armagh. In the mid 1600s, Ussher calculated the Earth had a beginning date of 9 AM on Monday, October 23rd, 4004 BC. Ussher's incredibly precise beginning date for the Earth had some longevity. It was actually still being printed throughout the English speaking world as late as the early 1800s. To the Christian imagination, the planet was 6000 years old. It's as simple as that. And its surface looked the same as it always had. Mountains, like everything else, had been brought into being during that first frenzied week of creativity laid down in the book of Genesis. Mountains were made on the third day, the same day that the polar zones are frozen and the tropics were warmed. The first book to a road the biblical orthodoxy, the first to actually imagine a past for mountains, might have been Thomas Burnett's, The Sacred Theory of the Earth published in 1681. Thomas Burnet was an Anglican churchman from Cambridge, England. And for a whole decade, Burnet served as a chaperone to a succession of teenage aristocrats, all taking the Grand Tour. The Grand Tour was one of the earliest forms of modern tourism from the 17th and 18th century. It was a rite of passage for many young English and European elites to polish off their formal education by exposing themselves to continental architecture and to geography, to history and culture. And so visits to Paris and Geneva and the major Italian centers in the south were especially popular. The tour required a crossing of the European Alps and it was here where Burnet became increasingly intrigued by mountains. What intrigued Burnet most about his various crossings of the Alps was the rubble, the broken rock debris that seemed to be scattered everywhere on the mountain passes. To Burnet the site was not only foreign, but it was chaotic, it was unsettling. Gradually the repeated sites of what he called, wild, vast, and indigested heaps of stone and earth, produced in him a desire to understand their origin. How did the rocks come to be so dispersed? He couldn't, he later wrote, feel easy, till I could give myself some tolerable account of how that confusion came into nature. For Burnet the biblical story of creation could not explain the appearance of the world. And key to the Earth's appearance was The Great Flood, that biblical story of a flood so great that it destroyed civilisation in an act of divine retribution. Where on Earth, literally, did all that water come from? For a flood that was so great, as the Bible specified, could cover the very highest of mountain tops. Burnet concluded that it would take 8 oceans of water, and this just didn't add up. A mere 40 days of rain, as it says in Genesis, could hardly provide enough water to even lap at the feet of most mountains. Burnet thus resolved that if there hadn't been enough water, then there must have been less Earth. And hence he set forth his theory of the Mundane Egg. Immediately after creation, Burnet proposed the Earth had been a smooth, unblemished spheroid, like an egg. It was flawless in appearance, it was uniform in texture, without hill or vale to disrupt its surface. But it had complicated inner architecture, a fiery core, the yolk. Now the white of the egg, these metaphors were all Burnet's, was a water filled abyss upon which the shell of the earth floated. That was the original make up of the earth. So what did Burnet's mountain building process look like? Over the years the action of the Sun dried out the Earth's surface, causing it to crack and to fracture. And the water below pressed up harder on those places where the crust was weakened until the point that it burst, and the resulting flood took the Earth. And when those waters finally receded, they left chaos behind. In Burnet's words they left a world lying in its rubbish. And so God hadn't created mountains at all. They were what was left the world's shell after it was ripped up by colossal hydraulics and they were signs of humanity's sinfulness. Burnet's theory incited a whole rash of criticism. People were outraged at Burnet's suggestion that the Earth in its current form was somehow imperfect, not to mention his wider challenge to the conventional understanding of the Bible. His book though was hugely popular and was perhaps the most widely read geologic work of the 17th century. For the first time the intellectual imagination became involved in positing possible pasts for mountains. Mountains were now worthy of contemplation. So just how old were mountains? Although Thomas Burnet challenged the belief that the visible world hadn't always looked the same, he hadn't actually suggested that it was older than the 6,000 years Ussher had calculated. It wasn't until the mid 1700s that the first significant extension of the Earth's age occurred. One of the first dissenters of the Young Earth Orthodoxy was a French natural historian, Georges Buffon. Buffon estimated the earth to be 75,000 years old and even that he felt was a conservative figure. His theory was a crafty one. By turning each of the seven Biblical days of creation into an epoch of indefinite length, he created the space and time necessary for geologists to begin their work of exposing a deep history for the earth, all the while staying within the bounds of Biblical scripture. The science of geology could now emerge and define itself in this newly old earth, without accusations of blasphemy. By the start of the 1800s, 2 schools of thinking emerged among geologists regarding the age of the earth and the origin of mountains, Catastrophism and Uniformitarianism. Catastrophism was the school that believed that the history of the earth was dominated by major geophysical revolutions that convulsed the planet with water and ice and fire and had all but extinguished life. Drastic tidal waves, global tsunamis, severe earthquakes and volcanos, the passing of comets, all of these events had shaped the earth surface into its present disruption. Uniformitarianism offered a counter theory. They held that the Earth had never been subject to a global catastrophe, earthquakes yes, volcanoes yes. These phenomena had certainly taken place through a geological history, but they were localized events. They rearranged the landscape only within their own vicinity. The Earth's surface certainly had been subject to drastic change, but that change had been achieved astonishingly slowly by forces of wear and tear. Given sufficient time, the conventional ordinance of nature, rain, snow, frost, rivers, seas, they could produce the largest of effects. For their theories to work, uniformitarians needed time, they needed great time. And so they ratcheted the beginning of the Earth far further backwards than anyone had previously. The foundation of the uniformitarian theory was that the present is the key to the past. In other words, the history of the Earth could be understood from the careful observation of present processes at work on the Earth's surface. So what about the apparent permanence of mountains? Simply an illusion born of our short life span. Were we to live for eons we would witness the complete rearrangement of the Earth's surface. We'd watch mountains being worn down into the plains, and we'd see new land masses formed under the sea which would be lifted up to create new continents and mountain ranges. What about those sea shells, the ones that could be found embedded on rocks on mountain tops? The great flood hadn't put them there, they'd been elevated from the sea floor to the mountain top by the patient, gradual processes of the Earth. More than anyone, Charles Lyell, a Scottish geologist, educated the masses of the 19th century in the language and imagination of geology with his book The Principles of Geology. There was wide appeal to the knowledge that Lyell laid out. He didn't need any special equipment or long training to decipher the Earth's history. You only needed a pair of acute eyes and basic knowledge of uniformitarian principles. Anyone with these minimal qualifications could now attend the most thrilling show on the earth, its past. To see this new way of thinking let's turn to Valparaìso on the Pacific coastline of Chile. It's from here on August 14th, 1834 that a 22-year old Charles Darwin set off on horseback into the Andean hinterland. Darwin was circumnavigating the globe as the scientific observer aboard the HMS Beagle. It was the voyage that would inspire his famous thinking on natural selection. Darwin had taken with him a copy of Lyell's book. By the time the that Beagle rounded the bottom of South America, the young naturalist was already interpreting the landscape in Lyellean terms. Note how Darwin for example describes the bird's eye view high above Valparaiso on top of the 1900 meter high peak, Cerro La Campana. >> We spent the whole day on the summit, and I never enjoyed one more thoroughly. The pleasure from the scenery in itself beautiful, was heightened by the many reflections which rose from the mere view of the grand range. Who can avoid admiring the wonderful force which has upheaved these mountains, and even more so the countless ages which it must have required to have broken through, removed and leveled, whole masses of them. >> Moments like this littered Darwin's journals. What had so excited Darwin as he gazed eastward to the main chain of the Andes was the experience of deep time, and it was thrilling. It had quickly become the stock and trade way to view mountain. Amateur science now provided a reason, an excuse for traveling to the mountains and a whole new generation was drawn to the hills. It's easy to experience this sense of deep time if you spend enough time in the Continental Divide of the Canadian Rockies. We would like to now take you to a special place in Yoho National Park called the Burgess Shale. This is the site of the world's first protected complex marine ecosystem and it's part of the Canadian Rocky Mountain Parks World Heritage Site. I had the opportunity to visit this extraordinary place where the remnants of an ancient sea floor can still be found among the highest peaks with Todd Keith, a Land Use Specialist with Parks Canada. Have a look. So this place where we're standing today has been considered a geological paradise for over 100 years. Todd, can you tell us a little bit about it? >> Sure, we're standing on the shores of beautiful Emerald Lake in Yoho National Park. With Mount Burgess in the background on this side, and Mount Wapta and it's near here on the other side of Mount Burgess. In the Kicking Horse Valley during the 1880s, railroad workers working for the Canadian Pacific Railway found fossil trilobites on Mount Stephen that they came back and called stone bugs. And in 1887, Richard McConnell, working for the Geological Survey of Canada, published a report on what he found on Mount Stephen. That report attracted the attention of Charles Walcott, a paleontologist and secretary of the Smithsonian Institution in Washington and he was an expert on trilobites. And in 1909, he found some very unusual fossils that he collected above Emerald Lake. And that was interesting enough for him that he came back for five field season to do some significant excavations and eventually collect 65,000 or so fossil specimens from this area. And that area he worked now became known as the Walcott Quarry. And he named it the Burgess Shale as it was close to Burgess Pass. And that quarry can be seen on the ridge behind us which joins Mount Wapta to Mount Field, and we call Fossil Ridge and it's since been designated a UNESCO World Heritage Site. >> Yes, it has been designated a World Heritage Site in 1980 and that's because the Burgess Shale is recognized as the most important fossil deposits in the world. It's 505 million years old which places it in the middle of Cambrian period. And the Cambrian was the time life first began to rapidly diversify into many different complex life forms from what previously had been very simple organisms. And that's called the Cambrian explosion which occurred near the start of the Cambrian period. So most fossil deposits in the world they preserve hard parts of animals, like shells and bones and teeth. But what's really unique about the Burgess Shale and a few other deposits around the world is that the Burgess Shale preserves the soft tissues of organisms. >> Todd, what do we have here? >> Well, here we have just a small sample of some of the fossils from the Burgess Shale in Yoho National Park. These two here are trilobites from Mount Stephen. So these are the types of critters that would have been called stone bugs when they were first discovered. They are composed of a hard exoskeleton, so they are actually quite easily preserved and are found commonly in fossil deposits throughout the world. But really what makes the Burgess Shale very important from a scientific point of view and much more unique than most fossil deposits is the fact that it preserves animals like this here which is a worm called Ottoia prolifica. Was very prolific within the Burgess Shale, they've collected many of this organism. And it's entirely soft, in some cases they can even see the gut trace when they look at it with a microscope. And, in exceptional cases, even see what it was eating. Another one entirely soft is this tubular sponge here called Voxia. Again, a soft tissue animal that is preserved here in the Burgess Shale. This one is very interesting because it is one of the very first chordates known from the fossil record. And chordates are a group of animal that evolved to include all vertebrates which includes humans. >> So this is our ancient ancestor. >> This fossil, Picaya, is an ancient ancestor to us. >> And finally here I have Marrella splendens which is one of the most common fossils found in the Burgess Shale. A very delicate invertebrate, soft tissue, and many of the specimens of Marrella show a dark stain around the abdomen and that's interpreted to be the bodily fluids squished out when the organisms were buried. >> So, there's been over 200,000 specimens collected from the Burgess Shale. If you'd like, I could go and show you some more of them from our Visitor's Centre in Field. >> Let's go. That'd be great. >> All right. So, we're here in the bustling Yoho National Park Visitor Centre at our Burgess Shale display where we have a collection of fossils from the Burgess Shale that help to illustrate the diversity of the animals that are found there. For example here is one of the classic fossils from the Walcott Quarry at Burgess Shale. It's a marine arthropod called Sidneyia and it's one of larger fossils that are found commonly in the Burgess Shale. >> It's named after Charles Walcott's son, Sidney. This fossil also illustrates quite nicely the detail that's found in some of the fossils. You can see the eyes on the side of the head. And this one's a polychate worm called Burgessochaeta. And it's a small, soft-bodied worm that has a series of bristles all along the length of its body, and they're preserved in quite fine detail. >> And when would these fossils have been found? >> So most of these fossils would have been collected by the Royal Ontario Museum during their research and explorations that they began in 1975, and then carried on fairly continuously from 1980 through to 2000. At that time, there was a hiatus in the research and excavation at the Burgess Shale sites. But since 2008, the Royal Ontario Museum has renewed their interest in field research related to the Burgess Shale and they've been continuing to find new discoveries. In 2012, they found a brand new fossil site in Kootenay National Park, within the Burgess Shale. And their early work on that suggests that it will be as significant as the Walcott Quarry. So there's still lots to learn. And that's one of the great things working for Parks Canada and being able to protect these fossil sites is that they're there for further research. Paleontologists continue to discover new things that shed light on the evolution of animals. And we also love to take people there to show them some of this in person. So, it's really important to have these sites protected within Yoho and Kootenay National Parks. >> Todd, thanks for showing this to us. >> Well, you're welcome. >> The 1800s was the century when the popular perception of time was extended. And this backwards extension accounted for former worlds which were inhabited by creatures that offered a great thrill beyond the excitement for antiquity. The discoveries of Mary Anning, an English fossil collector and others, did much to shine light upon ancient ages of monstrous creatures, mammoths and mammals, sea dragons or giant lizards, dinosaurs as they were christened in 1842. These discoveries had all intensified interest in the Earth's past. And geological tourism, fossil collecting, exploded wherever rock thrust upward in the mid to late century.