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Time's Waypoints
The Deep History of the Churchill Quartzite
As we pass through life we accumulate scars, each of which tells a story about an event that affected us. This white line on my hand shows where I fell hard on a tree stump in Nova Scotia when I was 19 years old. That pain in my ankle reminds me of an injury from another fall 30 years later, on an oil-slicked seashore. The older we get, the more of these old scars and injuries we will accumulate.
It is the same in the natural world. Very old natural things, whether they are living or inanimate, carry many sorts of evidence with them. In the case of rocks, this evidence can tell us the stories of all the events that affected a rock between the time it was formed and the present day.
Manitoba is home to many very old rocks; at least 2/3 of our province has bedrock that is about 1.7 to 3.5 billion years old, dating from the mid part of Precambrian time. Many of these rocks are beautiful and memorable – consider examples such as the granites and schists of the Whiteshell, east of Winnipeg – but to my eye the most memorable is the Churchill quartzite. This is the blue-grey to dove grey stone that forms the sculptural, sinuous "whaleback" ridges on both sides of the mouth of the Churchill River near Hudson Bay, so often seen as the backdrops in photos of polar bears.
The Churchill quartzite forms many "whaleback" ridges, such as this one seen in panoramic view at Airport Cove (note this year's quarrying activity!).
The Churchill quartzite has long been remarked upon by visitors to the Churchill area. It was first described and named by the Geological Survey of Canada geologist Robert Bell in 1880, and though the name "Churchill quartzite" was assigned so long ago, it has never received a formal scientific description, so the word "quartzite" is not capitalized.
The first waypoint of Churchill quartzite's time travel was its formation. Although it is a "youngster" in comparison with some of the Precambrian rocks east of Lake Winnipeg, it is still deeply old. Somewhere around 1.8 billion years ago, what is now the Churchill area was covered by large rivers that flowed from newly rising mountains nearby. Since the riverbeds were steeply sloped, the rivers carried an abundance of coarse sediment: quartz grains, dark minerals such as mica and magnetite, and fragments of various rocks (some of which could be quite large).
The Churchill quartzite is a metagreywacke, a metamorphosed "dirty sandstone" that can contain large rock fragments such as the rounded white piece in the middle of this photo.
Where the flow of those rivers slowed, they deposited sediment. The Churchill quartzite contains evidence that it was deposited by flowing water, and that the flow was variable: features known as cross beds were formed as the sediment was laid down on angled or curved surfaces, in places such as river sandbars. Over long intervals of time, this deposited material was buried in more sediment, and pressure from the weight of that sediment turned it to stone. The sand, varied minerals, and rock fragments formed a dirty sandstone, known geologically as a greywacke.
Beautiful trough cross beds can be seen in the Churchill quartzite at Sloop Cove. The dark lines show where grains of heavy minerals such as magnetite were the first to fall out of the water as river flow slowed.
Through yet more geological time, this greywacke was buried ever deeper, where it was subjected to heat and pressure from the ongoing geological activity in this region. This welded the sediment grains together, giving the rock the remarkable toughness for which it is prized today by people building railways and airports. The greywacke had been metamorphosed and became a metamorphic (changed) rock, the metagreywacke that we call the Churchill quartzite.
Twisted quartz veins in the Churchill quartzite show that it was subjected to great heat and pressure.
As time continued to pass, the nearby mountains were worn flat by erosion, and the tough, deeply buried Churchill quartzite was slowly uplifted until it was again exposed at the Earth's surface. For many millions of years, this bedrock was subject to the forces of erosion in a desert-like landscape; the rock surfaces were smoothed and weathered, and large boulder fields developed at the bases of quartzite slopes.
Dolostone from the Ordovician Period was deposited around an ancient boulder field, at the foot of a scarp of Churchill quartzite. The old quartzite island was to the left in this photo, and the Ordovician sea was to the right. This is the site depicted in the Museum's Ancient Seas exhibit.
More than a billion years after the Churchill quartzite was formed, another waypoint was added to its time journey. The Churchill region was now near the equator, and a warm sea flowed in and covered the area. Water extended to the horizon in all directions, but the tough ridges of quartzite stood up above the water, so that they formed an archipelago of islands in that tropical sea.
The ridges of Churchill quartzite (brown areas on this map of modern Churchill) formed islands in the Ordovician tropical sea.
Around these islands, abundant sea life lived: creatures such as trilobites and giant cephalopods swam in the water, while corals proliferated in front of and against the quartzite shores. We see evidence of this sea life in Ordovician and Silurian age dolostones (rocks similar to limestones) and sandstones that date from about 450 to 440 million years ago; in some remarkable instances the fossil-rich rocks fill crevices in the quartzite surfaces!
These fossil corals show how tropical marine life proliferated against the quartzite shores.
A crevice in the quartzite scarp is filled with Ordovician dolostone, which is itself full of pieces of weathered quartzite!
The sea became deeper, and during the Silurian and the subsequent Devonian Period, it is likely that the sculpted ridges of Churchill quartzite were again buried, with hundreds of metres of sedimentary rock laid down above them. An immense length of time passed, hundreds of millions of years, the sea was gone, and the thick sedimentary rocks above the quartzite were slowly eroded away by water and wind.
About two and a half million years ago, a different erosional force arrived in the region. The Ice Age, also known as the Pleistocene glaciation, began, and large continental glaciers began to expand southward from the Arctic. These glaciers eventually covered much of North America, and in places they were two to four kilometres thick! The immense weight of this great thickness of ice gave it immense erosional power, and as it moved slowly southward across the land surface it deeply eroded and scoured the bedrock surfaces.
Striations on a polished quartzite surface show the direction(s) of glacial ice movement. Here, Dr. Maureen Matthews demonstrates striations east of Churchill Airport.
As was the case during earlier erosion intervals, the immense toughness of the Churchill quartzite meant that it fared better than the other rocks around it. The dolostones that overlaid and abutted the quartzite were heavily ground down, to the extent that they can be observed in only a few select places in the Churchill area. The quartzite ridges themselves, in spite of their hardness, show considerable evidence of glacial erosion: in most places their surfaces were polished by the ice and show striations, lines and grooves that demonstrate the varied directions of ice flow as the rock fragments stuck into the bottom of the glacier scraped the top of the bedrock.
East of Halfway Point, the quartzite ridge along the shore has the features of a roche moutonée: it is curved and polished on the north side (left), while the south side (right) shows many places where pieces of the rock were plucked and carried away by the flowing glacier.
In some locations you can see other features characteristic of glacial erosion: a roche moutonnée, or sheepback, shows where a large chunk was plucked out of the downstream side of a quartzite ridge, while the upstream side of the same ridge was smoothly polished. Chatter marks are smaller features, crescent-shaped gouges that show evidence of chipping by rock fragments on the base of the glacier; these are typically at right angles to the direction of ice flow (which is itself demonstrated by the striations, or lines on the bedrock surface).
At Sloop Cove, near the 18th century British graffiti, glacial chatter marks are outlined by the growth of orange lichens.
In southern Canada the Ice Age began to end roughly 12,000 years ago, and by 8,000 years ago the ice in northern Manitoba had melted to the extent that the Tyrrell Sea had formed – this forerunner of Hudson Bay was a huge body of water that covered the low-lying land that had been pushed down by the weight of the glaciers. Our ridges of Churchill quartzite were now again under deep salt water; old beach ridges show that the Tyrrell Sea extended many tens of kilometres south and west of Churchill.
Near Fort Prince of Wales, old beach ridges are far above the modern sea level.
This region has been rising ever since, and even today the Churchill area continues to rise at a rate of almost a metre a century! This continued uplift is shown by the relationship between some human structures and the quartzite ridges. For example, old mooring rings at Sloop Cove, near the Churchill River, show where people were able to haul sloops (small ships) out of the river in the 18th century, to protect them from ice during the long northern winter. The cove has risen so much in the past 300 years that there is no way a ship could be hauled out in the same place today!
In the 21st century, there is no way we could overwinter a ship in Sloop Cove.
Sloop Cove is one piece of the final chapter in the saga of the Churchill quartzite. The sinuous ridges have actually been associated with humanity for several millennia, ever since Pre-Dorset Inuit people living some 3500 years ago hunted marine mammals from what was then an archipelago of quartzite islands in the Tyrrell Sea. More recently, the men of the Hudson's Bay Company quarried large blocks of this tough stone for construction of the impressive 18th century Fort Prince of Wales and Cape Merry Battery, which flank either side of the mouth of the Churchill River. Those men also carved the names of many men and ships into the cross-bedded quartzite at Sloop Cove.
Eighteenth century graffiti at Sloop Cove
In 2022 a huge amount of Churchill quartzite was being crushed at Airport Cove, to provide ballast stone for improvements to the Hudson Bay Railway.
In the 20th and 21st centuries, Churchill quartzite has been put to many uses by enterprising humans: it makes superb ballast stone for the Hudson Bay Railway, it has been used to construct the large weir that controls flow of the Churchill River, it underlies the runways of Churchill Airport, and it appears as a backdrop in all those wonderful photos and videos of polar bears in their natural habitat!
What does the future hold, I wonder, for such a remarkable and robust geological formation? In any case, it will be here for many millennia to come.
This post draws on images and observations from our very successful August, 2022, Museum research trip to the Churchill area, which allowed our group to develop many ideas for new exhibit collaborations. A few of the photos are from earlier paleontological fieldwork in the Churchill area over the past 26 years.
Some human usage of Churchill quartzite has been quite whimsical. This structure at Churchill, which looks like an ancient castle ruin, represents a never-completed stone hotel. The walls, built directly onto quartzite bedrock, include cobbles and boulders of many different kinds of stone.
A Bison Rubbing Stone in the Prairies Gallery: How Did That Boulder Get There?
The bison rubbing stone is beside the Pronghorn Diorama, at the entrance to the Prairies Gallery.
Bison rubbing stones are icons of the prairies. These large stones were originally transported south by Ice Age glaciers, then left behind on the prairies when the glaciers melted and receded roughly 12,000 years ago. They are therefore considered to be a form of fieldstone, and such large blocks of fieldstone are commonly called glacial erratics.
In the millennia since the glaciers left this region, rubbing stones have undergone a lengthy and intensive polishing process. These are boulders that were tall enough that they were made use of by itchy bison, who needed to shed their heavy winter coats or scratch after being bitten by flies and mosquitoes. The rubbing by bison over such a long time interval, along with the oils from the animals' hides, gives rubbing stones a distinctive patina, and a rubbing stone is typically surrounded by a ring of flattened, eroded earth.
A rubbing stone at the Star Mound historic site
For our new Prairies Gallery, we knew that we wanted to include this sort of defining prairie element as a full-sized touchable piece, but we also knew that a cast or sculpted stone just wouldn't do it. We had to acquire a real stone, and it had to be light enough that it could be moved into our gallery and placed safely on the gallery floor for an indefinite period of time. Since the gallery's weight allowance is quite limited, how could this possibly be done?
Kevin Brownlee, Curator of Archaeology, examined the stone when we first saw it outside Todd Braun's workshop in February, 2020.
As was the case for our fieldstone wall, we discussed this with stonemason Todd Braun quite early in the gallery development process. Although we thought that there should be a real boulder in the gallery, we also knew that it could not be a recognized rubbing stone, as those are heritage objects that should be left undisturbed in their original locations. Instead, Todd suggested that he could acquire a boulder of suitable size and rock type from gravel pits in the Morden area, and that he would prepare the boulder so that it could meet the floor loading limits and other requirements for placement in our gallery.
The stone is a boulder of migmatite, a rock type that exhibits coloured bands made up of different minerals.
Todd located the stone in late 2019, and we first saw it during a visit to his workshop in February, 2020. It is a very substantial boulder of migmatite, a high-grade metamorphic rock with aligned layers of minerals, which was formed under great heat and pressure deep in the Earth. Todd explained how he planned to cut off one end of the boulder so that it would be lighter and so that it would be stable standing on the floor. He would then use cutting and grinding power tools to hollow out the stone, starting from that flat end. It would therefore still look like a large solid boulder, but it would actually be more like a thick-shelled egg, with much of its internal mass replaced by air.
Todd Braun used power tools to hollow out the boulder (this is a still from a video by Todd).
Once we had a plan in place, the boulder had to wait until Todd had the time to prepare it. He was busy completing the fieldstone wall for our gallery, and was not able to turn his attention to the boulder until the fall of 2020. The cutting and hollowing of the stone turned out to be very labour intensive; the rock was very hard, and Todd was also afraid that fractures might develop if he tried to remove too much rock at once, or pushed too hard on it. It would have been a disaster to have the boulder go to pieces at this stage!
The boulder was hollowed out and ready to travel to Winnipeg (photo by Todd Braun).
Todd told us that we were getting our money's worth, since the job was more work than he had anticipated, but the hollowing out was completed by late November. He was also able to put a bit of a polish on the outer surface of the stone, to mimic the effect of rubbing by thousands of bison.
The boulder was lifted into Todd's truck . . . (photo by Todd Braun)
. . . and arrived at our loading dock very early in the morning (photo by Randy Mooi).
Todd used his tractor to lift the boulder into the back of his truck. Very early one morning, he drove to Winnipeg before there was significant traffic on the roads. The truck was backed into our loading dock, the hoist was attached to the heavy-duty straps that Todd had placed beneath the boulder, and the stone was lifted very smoothly onto a pallet jack. We were grateful at this stage that the boulder had lost so much of its original weight!
The loading dock hoist was used to lift the boulder from the back of the truck (photo by Randy Mooi) . . .
. . . and to position it on the platform, where the pallet jack could be lined up underneath (photo by Randy Mooi).
We had a crew of four on hand to assist Todd with moving the boulder into the gallery: an expert construction manager, and three curators to provide the grunt labour. Since we had measured all the doorways and halls in advance of this move, we knew that there would be a few tricky spots during the stone's travel through the building, but that it should just fit through all of those.
The boulder began its journey down the corridor toward the workshops (photo by Randy Mooi).
First, we trundled it down a long corridor and through the Museum's workshops, then out into the Welcome Gallery. Since there was new flooring in the galleries, we had to begin laying down sheets of board when we left the workshop space. There were several large plywood sheets, so it was a matter of laying down a row of boards along the planned path, then lifting each board after we passed over it, and moving it to the front of the other boards so that there would always be a safe surface for the pallet jack.
In the Welcome Gallery, the stone came as close to bison as it would ever be in its time at the Museum! Note the sheets of plywood protecting the gallery floor (photo by Randy Mooi).
The stone turned out to have a bit of a "mind of its own" when it came to the direction our route would take, and there was some manoeuvring required to get it lined up with the doorway that would take us into the Winnipeg Gallery area. This gallery was another tight spot, and after some discussion and changing of direction, the boulder slipped through. We then had a clear run to its final location by the Pronghorn Diorama.
In the Winnipeg Gallery, there was discussion of how we could get the boulder past some exhibits.
The pallet jack was rolled to the location that had been selected for the boulder's final position, and the stone was gently (VERY gently!) shifted onto some large wedges that Todd had brought along for the task. By levering with heavy pry bars, the wedges could be gradually removed and the boulder settled into place.
The last wedges were removed as the boulder was lowered into place (photo by Randy Mooi).
The next time you are in our new Prairies Gallery, I hope you will take a good look at the rubbing stone and other exhibits. Many Museum exhibits may look like simple things, but the stories behind them are often quite complicated!
Building Blocks of the Plains: A Fieldstone Wall in the Prairies Gallery
The Brockinton house is a humble yet beautiful fieldstone ruin in the Souris River valley.
Beginning in 2012, The Museum's curators worked together to plan exhibits for the Bringing Our Stories Forward project (BOSF). As we travelled around the grasslands region to prepare ideas for our new Prairies Gallery, we developed a list of topics that would be essential for a representation of this region. We rapidly agreed on some things that had to go into the Gallery: prairie vegetation, the importance of wind, Indigenous prehistory (and most particularly mound-building cultures), and several other topics. One of these was fieldstone.
A wall of the Brockinton house shows some of the geological variety of fieldstone types.
What is fieldstone, and why did we think it was essential?
When European settlers arrived on the prairies, they wanted to build permanent houses and other buildings. They were now in a region where there were almost no trees away from the river valleys, so material for wooden houses could be scarce. Many settlers came from parts of Europe where houses were built from stone that was quarried from solid bedrock, but on the Manitoba prairie the bedrock was either buried far below the land surface, or it was soft Cretaceous shale that was useless as a building stone.
There was however, a building stone resource that was readily available: loose fieldstone boulders, which lay on the land surface or could be readily found by digging near riverbanks. Fieldstone is a mixture of many kinds of stone. These stones formed as bedrock at different times, under varied conditions, and include igneous, metamorphic, and sedimentary rock types.
Some fieldstone structures in southwestern Manitoba are much grander than the Brockinton house. The photos above and below show St. Paul's United Church in Boissevain, built as a Methodist church in 1893.
Like the settlers, fieldstone had immigrated to the prairies. During the Ice Age (Pleistocene Epoch), huge glaciers covered Manitoba. Glacial ice flowed southward, pulling blocks of stone out of solid bedrock. Blocks (glacial erratics), left behind when the ice melted, are used as fieldstone. Most fieldstone thus originated far to the north of where it is found today.
Most fieldstone in southwest Manitoba comes from bedrock far to the north. This stone dates from the Precambrian (over 541 million years ago) and Paleozoic (541–252 million years ago) ages. In the Ice Age (2.6 million–10,000 years ago), the stones were picked up by glaciers and moved great distances.
Fieldstone occurs with other sediment in glacial deposits, such as here in the Assiniboine River valley near St-Lazare.
Since fieldstone was a distinctive natural material seen across many parts of the prairies, and since it was used by settlers when they built many of the early buildings, it was clear to us that the fieldstone story should be included in our Prairies Gallery. We already planned to build an exhibit about the Brockinton National Historic site, a significant precontact bison kill site in the Souris Valley south of Melita, so it made sense that we also create an adjacent exhibit that would represent a wall of the Brockinton house, a late 19th century structure that sits at the top of the slope above the archaeological site.
Fieldstone blocks of variable size are mortared together in a wall of the Brockinton house.
But how could we build this exhibit? Stone is really dense, and a mass of solid stone would have been far too heavy to be supported by the floor in our gallery space. Stone is also not really a topic that would have been suited to an animated video like our beautiful Prairies Mural Wall, and a flat panel display would have been just that: flat. We needed some way to allow visitors to observe and touch the genuine stone, in a setting that imitated a real fieldstone wall.
Fortunately, in our various travels around southern Manitoba we had met Todd Braun, a stonemason who works in the Altona area. By consulting with Todd and with our exhibit design team, a plan took form: a frame would be fabricated from steel clad in plywood, and Todd would prepare the stones to attach to that frame, reducing their weight by slicing them thin.
These are some of the fieldstone blocks that had been chosen by Todd Braun as possible raw material for our fieldstone wall.
Todd and I selected stones to represent the great variety of fieldstone seen in southwestern Manitoba. Many of these came from boulders and cobbles that Todd had found during his visits to various gravel pits. A few were rocks that we found together, and in one or two instances I went to other geologists to request examples of very particular rock types.
The selected stones were laid out so that we could see how they would fit into the wall.
A steel framework was fabricated in three sections to serve as a "skeleton" for the wall structure.
Once we had agreed on the stones to be used, Todd prepared them using traditional techniques, breaking each rock with a hammer until it had a blocky shape. These blocks were laid out in their approximate relative positions for the wall. After a fitted layout was achieved, Todd patiently took each block and trimmed it with a saw so that the visible surface was effectively a "veneer" with only a few centimetres of thickness. These veneers were then attached to the steel and plywood frame using adhesives and metal hardware, and the space between them was covered in traditional mortar. The "corner stones" were a particular challenge, since they had to be cut in such a way that they would look like solid three dimensional blocks once the wall was assembled.
The wall sections were tipped on their side to allow the sliced stones to be placed. Note how the corner stones have been cut so that they will look like three-dimensional blocks.
This view from the underside shows the substantial steel structure that underlies the wall.
The completed base section of the wall is light enough to be lifted by Todd's tractor.
To allow the wall to be assembled in Todd's workshop prior to its installation in our gallery, the frame was actually built in three sections. This made each piece light enough to be readily moved, and small enough to fit through the smallest doorway between the Museum's loading dock and our new Prairies Gallery. Very early one morning, Todd arrived at the Museum with the completed wall sections on his trailer. These were hoisted into the loading dock, and rolled through the Museum to the wall's permanent gallery location. Todd and our construction team had created an ingenious hoist system that would allow each upper wall section to be lifted into position on the base section. Once the wall sections were in place, they were bolted together, and Todd covered the joins with fresh mortar.
In the Museum, the upper wall sections were attached to a hoist and girder system so that the base section could be wheeled into place beneath them.
The base section was rolled in on two pallet jacks.
The finished wall looks very much like the walls you can see at Brockinton House and on other buildings in southwest Manitoba, and it beautifully demonstrates both fieldstone construction and the geological variety of this fascinating material. As is the case for some other Museum exhibits, there is no evidence of the incredibly complicated and lengthy development and construction process that allowed this structure to "look like the real thing."
The finished wall is surrounded by interpretive materials, telling the fieldstone story.
Finding the Impossible, Part 1: Getting There
In late autumn, the search for fossils in the Grand Rapids Uplands can be cold yet rewarding. Dave Rudkin of the Royal Ontario Museum visits a collecting site on a cold October morning.
This year, our Museum foyer has featured an exhibit of unusual fossils in the New Acquisitions Case. This exhibit, Finding the Impossible: Unique Tropical Fossils from William Lake, Manitoba, included a video "slide show" that documented the expeditions during which we collected these fossils. My colleague remarked to me the other day that this slide show should be shared widely using the Museum blog; this post, and some subsequent ones, will do just that!
The exhibit case and panel
The exhibit panel's text gives a brief outline of the project:
How does an animal become a fossil? How is a fossil jellyfish even possible? Only bones, teeth and shells are commonly fossilized, while soft tissues rot or are eaten by scavengers. Jellyfish and other soft tissue fossils are not quite impossible, but they are very rare, preserved only in unusual environments.
The fossils at William Lake are 445 million years old, dating from the Ordovician Period of geological time. They represent creatures that lived along a tropical shore when Manitoba straddled the equator. The remarkable preservation resulted from low oxygen and high salt levels in lagoons.
These specimens were collected by a Manitoba Museum research team, collaborating with scientists from the Royal Ontario Museum and University of Saskatchewan, and students from the University of Manitoba. During fieldwork in central Manitoba in 2000, we discovered the first of these soft-tissue fossils. Through hard on-the-ground work, we located the site. We travelled there numerous times, excavating thin dolostone (limestone) layers to extract the specimens displayed here.
The exhibit case
The first part of the accompanying slide show provided some background on Manitoba limestones, and shared the experience of travel to the Grand Rapids Uplands of northern Manitoba. I hope you will enjoy these images (please click on any image if you wish to see it full size).
Manitoba is famous for its Ordovician-age limestones (shown here in the Manitoba Legislative Building) . . .
. . . such as the fossil-rich Tyndall Stone. The fossil on the right is the receptaculitid Fisherites. This is a member of an extinct group of organisms; it is commonly called a "sunflower coral", but was most likely a green alga ("seaweed").
These limestones formed on a tropical seafloor about 450 million years ago (this is the Ordovician seafloor diorama in our Earth History Gallery).
To go from this seafloor to the shore (photo: Graham Young) . . .
. . . we must pack our gear (photo: David Rudkin) . . .
. . . and travel north (photo: Michael Cuggy) . . .
. . . to the Grand Rapids area.
Morning weather can be varied . . .
. . . as we get on the road, northward again . . .
. . . toward William Lake, in the middle of Manitoba.
The beautiful wilderness of the Grand Rapids Uplands . . .
. . . is home to a great variety of animals . . .
. . . and plants (upper left photo: Michael Cuggy).
Hydro lines span the landscape.
Limestone bedrock is very close to the land surface.
This limestone is home to many fossils.
To be continued . . . next time I will talk about the fossil collecting process, with many graphic images of dusty and hot, or cold and wet paleontologists!
Weird Tasks: Moving the Glyptodont
As we have worked our way through the pliosaur exhibit project, we have come up against a series of problems that have required novel solutions. About a month ago we carried out a very strange task, and one that none of us had ever had to do before: we needed to move the glyptodont.
Before I explain how we did this, perhaps I had better backtrack a bit, as you probably have some questions at this point: "What is a glyptodont, anyway? Where did the Museum get its glyptodont and why did you need to move it?"
The glyptodont, as featured in Ward's catalogue from 1866
Glyptodonts were creatures that lived during the Ice Age, that have been described as "fridge-size armadillos," although the largest ones could perhaps have been called "armadillos the size of Volkswagen Bugs." They were heavy, armoured creatures that weighed up to two tonnes. They spent their time lumbering around the forests and plains of South America and southern North America, eating trees and grasses. Glyptodonts became extinct about 10,000 years ago during the "Quaternary Extinction Event," at about the same time as giant ground sloths and other large mammals, probably as a result of climate change and hunting by humans.
Our particular glyptodont is a replica of a fossil that belonged to the genus Glyptodon, and like our ground sloth it came to the Museum by a long and circuitous route. The glyptodont and the ground sloth were among the earliest casts of big vertebrate fossils, produced during the late 19th century by Ward's Natural Science Establishment in Rochester, New York. Our ground sloth (Megatherium) was supplied to the Redpath Museum in Montreal in time for the opening of that institution in 1882, while the glyptodont joined it in Montreal some years later.
The Redpath Museum in 1925, showing both the glyptodont (left) and the ground sloth (right). (photo: McCord Museum)
By the 1960s, the Redpath was renovating, and these immense casts were removed and needed a home. The Manitoba Museum was under construction, so the casts were transferred to us and shipped to Winnipeg. They were assembled when the Earth History Gallery was constructed, and were there in time for the gallery opening in 1973. For the forty-plus years since then, both of these huge and historic casts have stood in place on the platforms that had been constructed for them.
The ground sloth and glyptodont, in their positions in the Earth History Gallery from 1973 to 2016
Now, in 2016, we are renovating that part of the gallery so that we can install our exciting fossil pliosaur, and to make space we have had to move the glyptodont. Since this replica had been in place since long before any of us worked here, we did not have any advance knowledge of how it should be handled, and since it is an irreplaceable artefact dating from over a century ago, we considered this move with some trepidation. Since it turned out that the glyptodont is also immensely heavy, having been constructed of plaster, wood, and iron in the best 19th century fashion, our trepidation was well placed.
Detail of the glyptodont, as it was from 1973 to 2016
As has been the case with handling the plesiosaur specimen, our technical staff love this sort of challenge, and Bert Valentin and Sean Workman had come up with solutions in the best "jury rigged" manner. Back when we installed our mineral exhibit, Bert had modified an engine hoist so that we could move our giant amethyst specimen, which weighs close to half a tonne. Now, with a fossil cast that weighs about the same amount (we weren't able to weigh it, so this is a best guess), Bert re-modified that hoist as a glyptodont-lifter. The following sequence of photographs shows how it went – the process was much more nerve-wracking than it appears here!
Bert Valentin crawls under the glyptodont to saw the head off, while Janis Klapecki and Sean Workman assist. The head will be taken out for conservation work, while we move the glyptodont's carapace.
The engine hoist is placed over the glyptodont, which is attached by thick straps attached to steel beams. The long pieces of wooden rail will allow us to control the tipping of the carapace when it is unbolted from the platform.
An end-on view shows how the steel beams are passed under and through the glyptodont.
Marc Hebert had built this extension to the ground sloth's platform. A cardboard cutout shows the location to which we will move the glyptodont.
Before Sean can begin to hoist the replica, Bert adjusts the attachments.
It is lifted, and the scary part of the operation begins!
Sean rolls the hoist, while Bert and I use the rails to keep the carapace steady.
Contemplating just how we are going to swing that heavy fragile antique up onto the platform . . .
. . . and here we go, using the cart to prop the base supports.
Traditional muscle power is used to slide the glyptodont to its final location.
The replica is now attached in place, ready for the rest of the exhibit to be completed around it.
Pliosaur Progress: We've Been Busy!
Debbie Thompson considers the splendid mount that she is creating for the pliosaur skull.
As you may know if you look at this page occasionally, for the past couple of years we have been working with a beautiful fossil of a pliosaurid plesiosaur, which was collected by Wayne Buckley from western Manitoba. We are now at the stage of preparing a permanent exhibit of the fossil, which will be installed in the Earth History Gallery this summer. So we have been very busy in the past little while!
The skull rests on a bed of artificial shale, constructed from a sculpting material over a wire frame filled with spray foam.
Much of my own work involves the planning of the exhibit: writing copy for the panels, selecting images and graphics, collaborating with the designer, and working with grants and budgets to ensure that everything is on track. While I am doing this, some of the other staff are carrying out very creative and exciting work: the designer, of course, but also those who are building cases, engineering hanging mounts for a skeletal reconstruction, and figuring out lighting and other technical issues.
A sturdy steel frame supports the entire mass of skeleton and mount.
Debbie fits pieces of "shale" that she has created to cover the skull edges. The skull had to be inserted on its own separate support mount that "slots" into place, so these smaller pieces are needed to hide the edges of that support.
As these photos show, one of the most creative tasks is that of artist Debbie Thompson, who is making an artificial stone (shale) bed that will surround the original fossils so that they will look almost the same as they did when they were first discovered. When Debbie's work is done, I think that many visitors will mistake her "rock" for the real thing, but as these photos show, this is only achieved through tremendous focus and patience.
The numbers represent all the pieces Debbie has sculpted to cover the edges of the separate support.
When Debbie had finished preparing all the "shale" for the skull surround, we needed to remove the skull to put it safely away. Here, Bert Valentin and Sean Workman move a specially adapted drywall lift.
Chains suspended from the drywall lift are attached into loops on the skull support.
As the skull is lifted, Bert makes sure that everything is kept straight. Note the yellow jacks on which the skull support rested; these allowed for very smooth lowering or raising of the support.
At its full height, the skull support is clear of the mount, and the entire lift can be rotated.
The skull is lowered to the cart that will transport it back to storage, where it will be safe until we are ready for the final installation in the Earth History Gallery.
If you want to read other posts related to this project, please look here, here, and here.
Flipping the Skull
The plesiosaur skull, as it appeared in our temporary exhibit last winter.
It is exciting and interesting to work with the fossils of large vertebrate creatures, but this is a field with many complexities. During the fossilization of most vertebrates, the bone was replaced by other minerals, which makes the skeletal components both heavier and more brittle than they were during the animal's life. For those of us working in the "back rooms" of museums, it can be very tricky to move these large, weighty, and fragile fossils as we prepare them, study them, or mount them for exhibit.
Janis Klapecki and Tamaki Sato, strapping the two cradles together.
A few weeks ago, we had to perform one of the trickiest tasks associated with big vertebrates: flipping a skull. The large pliosaurid plesiosaur that was donated to the Museum by Wayne Buckley had been fully prepared by Wayne, so that the bones are completely removed from bedrock; their weight is supported by mounts or cradles (structures similar to the plaster field jackets). This makes the fossil much easier to exhibit or study, but it means that we have to ensure that we are fully supporting the skull whenever we move it, so that it doesn't collapse or break. Since this particular specimen is unique and scientifically important, and since it has survived the past 90 million years or so in remarkably good condition, it is imperative that we take extra care!
Before we could begin the "flip", we had to turn the cradles so that they ran across the table. L-R: Kevin Brownlee, Amelia Fay, Tamaki Sato, Janis Klapecki, and me (photo by Stephanie Whitehouse).
In late September, we were visited by Dr. Tamaki Sato (Tokyo Gakugei University) and Dr. Xiao-Chun Wu (Canadian Museum of Nature), who spent several days here studying the skeleton for a scientific publication. Before they arrived, Debbie Thompson had been making the final exhibit mount for the plesiosaur; to allow her to do that work, the skull was resting in a temporary support cradle, with its "back" side (the side hidden during exhibit) facing up. We knew that Tamaki and Xiao-Chun would want to thoroughly examine both sides of the skull, and that at the midpoint of the week we would need to flip it so that they could study the "front" side.
Making sure we are all in agreement before we begin! Clockwise from left: Kevin Brownlee, me, Amelia Fay, Xiao-Chun Wu, Tamaki Sato, Janis Klapecki, and Roland Sawatzky (photo by Stephanie Whitehouse).
Knowing this in advance, Debbie had prepared a second cradle that would fit onto the the side that was currently up, making this support out of wood, plaster, burlap, and other materials. Unfortunately for us, Debbie was on vacation when the visiting scientists were here, so it was left to the rest of us to ensure that the cradle was used as she had intended.
On the Wednesday afternoon, Collections Specialist Janis Klapecki and I went to the room where the plesiosaur is laid out, and with Tamaki and Xiao-Chun we fitted Debbie's second cradle over the skull. The fit was perfect, so we wrapped sturdy packing straps around the two cradles, then tightened them until there was no give and the wood supports were flexing a bit. This tightness would ensure that the bones would move as little as possible during the flip.
Click the image to download a short video of the flip (2 MB; video by Stephanie Whitehouse).
When we were ready, we were joined by several of our curatorial colleagues, who had kindly volunteered their assistance. The skull and cradles were not immensely heavy, but the operation had to be done very steadily and smoothly, so it was best to have two or three people on each end of it. Once we had everything in place, and once we had discussed how we would do it, it only took a couple of moments to actually flip the skull.
Before we could remove the "lid", we had to check that the skull was not sticking to it anywhere (photo by Stephanie Whitehouse).
When we removed the straps and exposed the skull, it was clear that the planning had paid off: the fragile fossil had survived it perfectly. Tamaki and Xiao-Chun could continue their scientific study, and the rest of us could return to our many other tasks. But we aren't quite done with this sort of work yet: we will have to flip the skull at least a couple more times before it goes into a new permanent gallery exhibit next year.
The upper jacket is removed (photo by Stephanie Whitehouse).
Success! L-R, front: Tamaki Sato, Stephanie Whitehouse; back: Xiao-Chun Wu, Janis Klapecki, me, Roland Sawatzky, Amelia Fay, Kevin Brownlee (photo by Xiao-Chun Wu).
Tamaki and Xiao-Chun return to their scientific studies.
Cleaning Week: Filing Trilos
An enrolled and incomplete cheirurid trilobite, possibly belonging to Ceraurinus
Last week was the Museum's "cleaning week", during which we were closed to the public so that we could focus on getting our house in order. There was much recycling of paper, moving of old furniture, and scrubbing of walls in many parts of the Museum. Here in the Geology and Paleontology lab, we decided that this was the ideal time to file some of the fossils that had been catalogued in the past few months. Most particularly, we put away several hundred Ordovician age trilobites from the Stony Mountain Formation at Stony Mountain, just north of Winnipeg.
Some of the catalogued trilobites, ready to be filed away
How did the Museum end up with hundreds of trilobites that needed cataloguing? Stony Mountain is one of the really important sites in southern Manitoba dating from the Late Ordovician Period, about 445-450 million years ago. During this time central North America was covered by tropical seas, and at Stony Mountain the limestone deposits are tremendously rich in fossils of marine invertebrates: corals, brachiopods (lamp shells), trilobites, and many other kinds of creatures.
The invaluable Ed Dobrzanski did most of the work on this project.
Staff and volunteers from this Museum and its predecessor have collected fossils at Stony Mountain since the 1930s; over the years thousands of specimens have been catalogued to our collections, but very few of these were trilobites. A museum always collects more samples than can be catalogued quickly, and the Stony Mountain trilobites are somewhat complicated and consist mostly of small pieces*, so we had been holding onto them until there was time to consider which ones belonged in the permanent collection.
Components of a trilobite that may belong to the genus Failleana (that's a cranidium, the mid-part of a head, on the upper left)
We knew that the Stony Mountain trilobites had been gradually "stacking up", and volunteer extraordinaire Ed Dobrzanski and I had decided that we would devote some serious time and space to this project when we could. A few months ago the lab was looking relatively clear, so we laid out the hundreds of trilobites in trays and decided which ones were good enough to go into the permanent collection. I identified quite a few of them, but it fell to Ed to carry out the laborious, repetitive work of cataloguing each specimen.
The specimens were filed away in our collections room.
When he was done, there were some 150 catalogued batches, all neatly laid out and padded. Once I had reviewed his records (we always double-check everything for accuracy!), we still had to find space in the collections, shifting the drawers in several cabinets to free up a block so that the trilobites could all be together and organized.
One of the drawers of Stony Mountain trilobites
Finally, last week, we put the trilobites away! This may seem like a very big job for some small old fossils, but it means that many potentially important specimens are now properly recorded and stored, with the trilobites and their data readily available for future research or exhibits.
Trilobite components: the tail (pygidium) of a cheirurid on the left, and partial mouthparts (hypostome) of an asaphid on the right
*These trilobites are almost all incomplete because most trilobite fossils are from pieces of exoskeleton left behind when the animals moulted in ancient tropical seas. For the fossils at Stony Mountain, wave and current action on the ancient seafloor caused further abrasion and breakage.
Left Behind in Airport Cove
Our field group, walking across dolostone beds in the Silurian part of the cove.
If you think about how Museum paleontologists get fossils, you might guess that we go out and find where the fossils are, extract all of them from the rock and sediment, and return them to the Museum. Certainly that is what we do where fossils are scarce, but in many instances our job really consists of deciding what to leave behind. Our specialists at the Manitoba Museum are called curators, and a curator by definition has to be able to select what is needed for collections and exhibits.
A lovely example of the Ordovician gastropod (snail) Maclurina manitobensis, on a large block that is still in Airport Cove
This fact was really brought home to me in the past couple of weeks, as we revisited sites in Airport Cove, the stretch of shoreline north of the airport at Churchill. Airport Cove covers a large area, with many patches of bedrock spread across the shoreline. These patches of rock allow us to sample many different sedimentary beds from the end of the Ordovician Period and the beginning of the Silurian Period, roughly 445-435 million years ago.
In the cove, the rock seems to go on almost forever.
The rocks in the cove were deposited as sediment in warm tropical seas, so fossils are plentiful in many of them. With such an embarrassment of riches we have to be selective every time we go out in the cove; if I collected every decent fossil, we would need an entire freight train to get them to Winnipeg! And then, where could we possibly store them?
Two examples of the large Silurian brachiopod (lamp shell) Virgiana decussata
As a result of our previous work here, many examples of the "standard" fossils from Airport Cove are already resident in the Museum's collections, and this time we were looking for very specific and rare things. So we would walk around the cove each day, considering and photographing the more common sorts of fossils. Some of these are old friends, on blocks of stone that I can remember being in the same place ten or fifteen years ago. Others were new to me, but I can hope to see them again if I get back here. And then there are the few fossils that are so good that they must go to the Museum; one of these is shown at the end of this piece.
Abundant pieces of auloporids, Silurian "organ pipe" corals, in a dolostone bed low in the modern intertidal zone
If you are ever in the Churchill area and wish to go looking for fossils, please follow all guidelines on polar bear safety! We had to leave our work area at Airport Cove twice last week as there were bears nearby, and on one occasion a mother and cub walked right through our site very shortly after we got into the truck.
Old friends: we have been walking past this block of Ordovician stone for the past fifteen years or more. The elongate fossil on the left is the central tube (siphuncle) of a nautiloid cephalopod, while that on the right is an tall aulacerid stromatoporoid (sponge).
The pygidium (tail) of the Ordovician trilobite Isotelus
Another example of the gastropod Maclurina manitobensis (lower), with an unidentified fossil that might be a stromatoporoid sponge
The one we couldn't leave behind: this beautiful Ordovician coiled nautiloid cephalopod is now in transit to Winnipeg, along with the other fossils we collected.
The Fossils Surround Us
An orthoconic cephalopod (Armenoceras?) near the Planetarium.
Those of us who live in Winnipeg know that fossils are never far away. Many Winnipeg structures feature surfaces clad in Tyndall Stone, a fossil-rich dolomitic limestone of Late Ordovician age (about 450 million years old). Tyndall Stone covers public buildings such as the Manitoba Legislative Building and the Winnipeg Art Gallery, and commercial buildings in the downtown core, but it can also be seen in thousands of homes in Winnipeg: in walls, steps, and fireplaces.
Thus, it is hardly surprising that the Museum and the adjacent Centennial Concert Hall both use Tyndall Stone inside and out. Of course Tyndall Stone fossils are represented in our Earth History Gallery, but if you think about it, it is odd that there are so many more "museum-grade specimens" exposed to the weather on the outside of the building. On the inside, as these photos show, we sometimes cover up beautiful fossils with the detritus of everyday existence: signs, fountains, alarms, and thermostats. In part, this is because the fossils are so abundant that it is hard to avoid them when placing objects, but it may also be that they are so commonplace here that people ignore them and take them for granted.
Maybe someday we will add interpretative signage to some of the better and more accessible fossils on and in the Museum, but that would be a big project to undertake. In the meantime, here is a sampling of a few of the good ones.
The hallway near the elevators may look like an unprepossessing remnant of the 1960s, but those mottled walls are thin slabs of Tyndall Stone. This stone, quarried by Gillis Quarries Limited at Garson, Manitoba, is rich in fossils representing life from an ancient tropical seafloor.
Geologically, Tyndall Stone is part of the Selkirk Member of the Red River Formation; this bedrock formation underlies much of southern Manitoba, but it is only exposed in certain places such as in cliffs along Lake Winnipeg, and in the Tyndall Stone Quarries at Garson. Behind this clock, the darker mottles represent burrows in the ancient seafloor, made by millions of little arthropods or worms. The white structure to the lower left is the colonial coral Protrochiscolithus.
The big brown blob beside the elevator is a stromatoporoid sponge. To its lower right, a smaller dome-shaped stromatoporoid (brown dome) was encrusted by the tabulate coral Protrochiscolithus (white), and to the right is a honeycomb rugose coral (Crenulites?).
The pattern in the upper right represents the chain coral Catenipora, which grew on the ancient seafloor (a place with no risk of fire!).
The white thing beside the water fountain is an excellent example of a rugose coral (horn coral).
The ancient seafloor was mostly soft and muddy, but many of the creatures required firm or hard substrates. Since substrate was at a premium, animals often grew on top of one another. The dome-shaped structure to the lower left in this photo represents the colonial coral Protrochiscolithus (white part), which grew on top of a stromatoporoid sponge (brown part).
As common as dirt: there are so many fossils in these walls that some very good ones, such as this cephalopod, have been covered by things like this thermostat.
Since there are so many fossils in the relatively small area of the foyer walls, imagine how many there are on the outside of the Museum!
Curator of Geology & Paleontology
Graham Young grew up in Fredericton, New Brunswick. After doing a B.Sc. in biology at the University of New Brunswick, he switched to geology and did an M.Sc. in paleontology at the University of Toronto. After completing a Ph.D. at the University of New Brunswick in 1988, Graham spent two years in Newcastle, England, studying fossils from the Island of Gotland, Sweden. He moved to Winnipeg in 1990 to do research at the University of Manitoba, and has worked at the Manitoba Museum since 1993.
At the Museum, Graham's curatorial work involves all aspects of geology and paleontology. He is responsible for building the collections, dealing with public inquiries, and preparing exhibits. Over the years, Graham's research has become broader in scope, moving from specialist studies of fossil corals, towards research on ancient environments, ecosystems, and unusual fossils such as jellyfish and horseshoe crabs. Most of his current field research is on sites in the Grand Rapids Uplands and elsewhere in northern Manitoba.
Collections & Conservations