Up the Gatineau! Online Articles
The following article was first published in Up the Gatineau! Volume 41.
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The Sculpted Rocks of Cantley
by David Sharpe
I first saw the Cantley pit on a summer drive while visiting friends in Ottawa in 1976. As someone who has always been interested in landscapes, something about the newly exhumed rocky ridges caught my eye. The smooth, curved slopes looked different than the glacially scratched rocks that I had walked across in the late 1960s, in my student days as a geological assistant in northern Ontario.
I returned to the pit shortly after moving to Ottawa in 1982 to start my calling as a research scientist with the Geological Survey of Canada (GSC), studying the glacial geology of Canada. I have been informally studying the site ever since. Over the years I have visited the Cantley pit with newspaper and television journalists, artists, colleagues, field geologists from around the world and many university students—all out to admire and test their mettle on the rocks of Cantley. My career with the GSC, which has taken me many places across the glaciated landscapes of Canada and other countries, provides me with a perspective to write about the Cantley pit.
The rocks of the Cantley pit have an arresting aesthetic appeal that catches most visitors off guard. I might be able to explain the scientific interest and significance of their smooth curves, but perhaps not the essence of their eye-catching allure— something that only an artist can capture.
The Cantley sand pit has had a humble recent history, compared with its dramatic geological past. It served as pasture land for the McClelland dairy herd for decades into the 1950s, prior to its aggregate exploitation for industrial products across the region. Cantley resident Hubert McClelland walked the gravel hills as a boy with his family’s herd of cattle, and has wonderful childhood memories dating from before excavation began on the pit. Little did Hubert know that some of the most amazing rocks in the geological world lay hidden beneath his feet.
The beginning of the Cantley “pit”
Prior to 1954, there was no pit; its site formed the northern half of the McClelland family farm, still lived on today by Hubert. It was used as day pasture for the family dairy herd; Hubert would fetch the cattle from the grassy gravel hills and bring them back to the barn for late-afternoon milking. Until the gravel was removed, the only evidence of glacial action was on a wooded rock outcrop to the south on the McClelland farm.
The site, a high gravel hill, is 0.3 kilometres north of St. Andrew’s Road and St. Andrew’s United Church, bounded on the west by forested areas and on east by the Cantley Road (now known as Highway 307). In 1934, Hubert McClelland’s paternal grandfather, also named Hubert, sold four acres of the gravel hill opposite the spring (La Source) to an Ottawa company owned by Harry Hailey. Hailey acquired it for its high-quality gravel, to manufacture cinder blocks.1 In 1954, Hubert’s father, Trevellyn, sold the remainder of the gravel hill to J.P. Chenier Co. Limited, which also acquired the four-acre Hailey pit. As a condition of the sale, Hubert’s father reserved the cut of white pine, spruce and balsam on the gravel hill and harvested it before topsoil was removed to access the sand and gravel beneath.
The top of the gravel hill was about 180 metres above sea level, as high as the land on the other side of Highway 307, which was already a sand and gravel operation. Because of these high hills, the early Cantley Road passed through a gap that was narrower than the present highway’s right of way. From 1954 to 1970, for 52 weeks of the year, four to five trucks a day transported gravel from here to Hull for cement-making and other construction activities.
Later, Mr. Pageau obtained mining rights to the Cantley pit from Chenier, as well for two McClelland properties to the south. He experimented with a dolomite rock quarry on the site in the summer of 1980; this is visible where a flat portion of the formation has been broken away. Dolomite is a white crystalline carbonate rock used for decorative stone, construction aggregate, and lime and cement manufacture.
Cantley: a study site for all time
The moulded pit rocks that we marvel at today had a tumultuous beginning, as continents collided and mountain ranges formed. Coloured minerals that crystalized during that period now provide excitement for miners and rock-hounds alike. Over the geological ages the mountains were slowly worn away, yet our splendid Gatineau Hills survived.
When I started with the GSC in the 1980s, I worked alongside a colleague who was mapping the Champlain Sea, an ancient arm of the Atlantic Ocean that captured glacial sediments, sand, mud and fossils about 12,000 years ago. This sea covered the Cantley area rocks and sand pit to more than 200 metres above the sea level today. The weight of the glaciers that covered the area then squeezed the land like a spring; the land has now rebounded (sprung back), and the sea has retreated down the St. Lawrence River valley to its present limit east of Quebec City.
Since European geologist Louis Agassiz introduced his controversial theory of glaciation in 1831, glaciers have been considered to be a force that has re-shaped the surface of the earth, particularly in places such as Canada. The majestic valleys and the snow-covered, jagged peaks and deep glacial tarns of the Rocky Mountains come more immediately to mind than the Gatineau Hills. But the hills around Cantley tell us that glaciers and diluvial floods likely co-existed here, so that both the glacial ice and the enormous quantities of water that flowed when the glaciers melted shaped the sculpted Gatineau rocks that we now appreciate and stroll across.
Rock formations around Cantley are related to primeval mountain-building events,2 created as the North American tectonic plate collided with Africa about 1 billion years ago. Ancient sediments (carbonate) were deformed to marble by intense heat (700° C) and intense pressure (the weight of 15 km of overlying rocks), and were re-shaped by massive granite intrusions. These events also led to the wealth of exotic minerals found and mined across the Cantley area over the years (and written about extensively by Don Hogarth,3 a prominent local geologist). These minerals form a beautiful and evocative collection of crystals of mica, graphite, feldspar and apatite in vivid silver, pink and green. Over the long period since the mountains rose, weathering eroded the massifs by way of ever-flowing rivers and, most recently, by glaciation.
The sculpted rocks of Cantley
In 1983, I was introduced to one of the most revolutionary ideas since the inception of the glacial theory, by John Shaw at Queen’s University. In describing some smooth, curved rocks near Kingston, he presented an idea that would change the way I looked at and interpreted glacial landscapes across Canada. Since the inception of the glacial theory, it had been reasoned that the slow grinding and transporting action of glacial ice eroded most bedrock and deposited most sediment on the landscape. While the work of glaciers was considerable, significant work was also rendered by catastrophic floods of meltwater that were let loose from on or under the great ice sheets that covered Canada, including Cantley, and parts of the northern USA.
The beautiful sculpted rocks of Cantley were shaped partly by glaciers, but more so by fast-moving glacial meltwater that rushed from under the melting ice sheet. Glaciers, with sediment at the base of the ice, acted like a sanding block that wore down the rocks at Cantley. But many other rock surfaces at Cantley show smooth depressions that apparently did not result from such sandpapering. The smooth hollows of these surfaces have no glacial striations, no sanding marks. They seem to have been formed by the swirling, erosive action of turbulent glacial meltwater flow.
The water that was believed to have sculpted the Cantley rocks also deposited a ridge of sand and gravel atop their eroded surfaces. Called an esker, this ridge was formed while a river of meltwater flowed beneath the glacier. Modern rivers also sculpt rock surfaces on river beds; such rivers can also cover their river beds with sand and gravel, similar to the sub-glacially formed esker at the Cantley pit. Modern and ancient glaciers around the world have left behind other smooth, sculpted rock surfaces, exposed to our eyes once the glaciers retreated.
Why is such an academic issue—erosion by glacier ice or by the rush of its trapped, sub-glacial meltwaters—of such concern to us? While this topic is of scientific importance, there are also practical reasons why it is significant. For example, those prospecting for minerals across Canada benefit from precise knowledge of how glaciated terrains were eroded and how sediment was dispersed and deposited. The world-famous diamond mines northeast of Yellowknife were found by prospectors who traced glacial directional pathfinders and sampled diamond indicator minerals in esker sand and gravel near Lac de Gras, NWT.
The Cantley Killpot, glacial kettles and eskers
A wooded depression next to a small gravel mound north of St. Andrew’s Road in Cantley, on the west side of Highway 307, is known to long-time Cantley citizens as the “Killpot.” The Killpot had no drainage outlet for surface water, so it is likely that a large block of ice, stranded from a retreating glacier, melted and formed a depression called a kettle, next to the excavated Cantley esker. This became a muskeg filled with moss, muck and tamarack trees, unique in Cantley.
Kettle lakes, which most geologists think formed as relic glacial ice blocks melted, are common at Esker Lakes Provincial Park in northern Ontario near Kirkland Lake. They are forming today in Iceland as ice blocks are melting following the glacial meltwater floods of 1996.
Hubert McClelland remembers venturing into the edge of the Killpot as a 10-year-old boy, only to become stuck in the muck to thigh depth before managing to scramble to solid ground. Perhaps other people, or animals, as the name Killpot suggests, were not so lucky as to escape this natural trap.
A geological theme park
Many scientific and academic groups (especially students) have visited the Cantley pit over the past several decades. If they had the opportunity, tourists would probably also visit such an attraction. In 1991, a proposal for a geological theme park was put forward by a group of interested citizens and landowners, including Hubert McClelland. Such a park would secure and preserve the Cantley sand pit long-term, as well as the property on the east side of Highway 307. It would capitalize on the interest in the Cantley sand pit and give it due recognition as an educational resource, creating a focal point for regional and civic awareness, recreation, and education for tourists and local residents.
The group argued that, due to its geological heritage, the site should qualify under Quebec’s Cultural Property Act as a “natural district, protected area and/or cultural property.” They urged the Cultural Properties Committee of Quebec to recommend that the Municipality of Cantley designate and protect the site by seeking adequate zoning changes.
The idea of preserving the Cantley sand pit was championed back then by Cantley journalist and dogged supporter of local history Bob Phillips, along with others. He wrote several articles about it for the Ottawa Citizen.4 Under a February 1990 headline, “In Cantley, a special site sorely in need of protection,” Bob summarized the case: “If you were to rate all the ancient geological sites in Canada according to a combination of scientific value and accessibility, one stands out. It is in Cantley.”
A week later his headline read, “Ancient secrets just aren’t safe here in Cantley.” He wrote that “Geology may not be as exciting as the New Kids, but it’s the real thing; it would hold its interest forever and it’s relatively cheap.” As a designated area attraction—a tourist site—the rocks’ secrets would be safe. Bob suggested that every great idea deserves a great motto, and came up with the catchy “Cantley on the Rocks.”
Later that year, Bob wrote further on this topic:
…so thoughts are turning to rocks. As faithful readers know, the Cantley pits on Route 307 give dazzling insight into how the planet was shaped before even we were born. Plans are afoot for the eventual development of this site for public pleasure and enlightenment; the old mine5 may yield a mother lode of tourism.
Unfortunately, this initiative never took off, even though interest remains high almost 25 years later. The owners of the pit since the early 1990s, Mr. Tremblay and Mr. Vanesse, have removed little sand and gravel from the site. What they have done is generously allow many interested visitors access to the pit.
The Cantley pit today
In October 2013, Hubert McClelland and I joined about 50 enthusiasts in a field trip to the site, organized by the local historical society, Cantley 1889. Hubert provided access to the site across his land, which is located southwest of the pit about 10 km north of central Cantley. Before I spoke on its geological background, Hubert provided a history of his farmland. We then hiked across his pasture to the summit above the quarry. An update on the stalled preservation plan was briefly discussed, and a Cantley councillor was reported to be interested in picking up the reins.
While considerable efforts have been made to secure the Cantley pit as a preserved educational geological site for the region, none has succeeded to date. What has succeeded is that the rocks of Cantley never cease to amaze us—whether from the scientific curiosity they arouse or by the sight of their natural beauty.
1. Ottawa homes and other buildings were heated with coal, and Harry Hailey’s company recycled coal clinkers with sand from the Cantley pit to manufacture a bluish grey cinder block, similar to a cement block, as a building material. With the popularity of heating oil after World War II and the decline in spent coal, the production of cinder blocks stopped and Harry Hailey’s pit went out of use.
2. This is known as the Grenville orogeny, and was dubbed the “orogenous zone” by Bob Phillips, the late Cantley writer and heritage activist.
3. Donald D. Hogarth, “A guide to the geology of the Gatineau-Lièvre District,” Canadian Field-Naturalist, Vol. 76, No. 1, 1962, pp. 1–55; “Geology of the national capital area,” 24th International Geological Congress, Guidebook Excursion B-23 to B-27.
4. These articles are available in the Ottawa Public Library’s Online News service.
5. Miners in the area hunted for mica, apatite (for fertilizer), iron, feldspar (for pottery), and quartz (crystal radios) in 100s of mines, pits, or trenches up to 60 metres deep. Most operations closed down after World War II.