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A Certain Logic

September 11, 2017

Churchill, Manitoba: August, 2015


 

The careful juxtaposition of the picnic table and sign must have required a very special sort of thinking. You are in danger if you walk in this area, but yes, it would be just fine to have a picnic. Please don’t forget to bring sardines for the bears. Polar bears like sardines.

 

© Graham Young, 2017

Going to Pieces on the Shore

September 1, 2017

Indian Point, Saint Andrews, New Brunswick: July-August, 2017


The tide is still going out.  Off the point, the gulls squabble among themselves in the wake of a passing boat. A guillemot floats on the swell much farther offshore, its white wings bright against the black body. You turn just in time to see the osprey flap past, flying low with a heavy fish in her claws as she labours toward her nest on Navy Island.

Clam, barnacles, and mussels (coin diameter is 24 mm)

Looking between your feet, you notice a few shells: clams, mussels, barnacles, periwinkles, the occasional crab carapace. They show white, brown, and blue against the gravel that forms this beach. The gravel is red, a beautiful deep ochre flecked with grey, black, and white. The red comes from pieces of the same old sandstone that forms the bones of this point. The grey and black are clasts of other rock: basalt, schist, and granite.

But what are those white grains interspersed through the gravel? They seem to be bits of shell – yes, crouching to look more closely, you can see clearly now that some of them are angular bits of clam, some are mussel shell bleached to pale lavender-white, and some might be particles of periwinkle. Others are odd – some of the most abundant are weird wavy pieces, and your best guess is that they are remnants of disintegrated barnacles.

Going to pieces: a gastropod (at top) and barnacle (centre) are slowly being broken down into the sorts of shell fragments that surround them (coin diameter is 24 mm).

There must be hundreds of shell fragments, possibly thousands, in that two-metre-square in front of you. Why are there so many bits of shell here, when there are only a few complete shells in the same area? The answer lies in that red gravel. To break up so much sandstone bedrock into little bits of gravel requires the application of considerable force over a substantial interval of time. That force was supplied by waves and currents, driven by wind and that twice-daily tide, day in and day out over seasons, years, and centuries.

Sandstone forms the bones of the point.

In winter, the ice and frost do their bit to break up rock and speed up the process. If you have been here during a big storm, you will have heard a deep roaring and grating, like the growl of a cement mixer projected through an arena-scale PA system. That is the sound of grains and cobbles grating on one another and on the bedrock of the point . . . and that really speeds up the process.

The same thing happens to the shells. The rich environment of this shore hosts huge numbers of molluscs and crustaceans, and as they die their shells are moved by the waves and currents, some of them transported into the swash zone where the water’s energy can really do its work. The white fragments you see here were all parts of the shells around living creatures – probably not very long ago given the power of the sea in this area, though of course it would be difficult to tell for sure without some rather detailed study.

Variations in shell content help to create the bands of colour in this beach.

Standing up, you wander slowly along the shore. You see that shells and shell bits are everywhere that there is  sediment, but the assemblages are made up of different kinds of shells as you move along the beach, and they are much more abundant in some areas than others. Here, the gravel is full of barnacles and barnacle bits. There, a tidal channel is packed with periwinkles, the living crawling over living and dead. In some places there are many complete shells, and in others it seems everything is broken.

Barnacles galore . . .

. . . and periwinkles everywhere.

Let’s walk up the shore now and stand on the low bluff. Looking down across this modest area of beach, how many shells and fragments are visible on the surface in front of us? Millions? Now consider that this beach sediment could have a depth of many metres, and it disappears where it slopes beneath the rippling sea.

Consider further that this beach also disappears from sight around the point to our left and right – but we know from experience that we might see similar shell-laden gravels if we drive to other shores around Passamaquoddy Bay, and if we drive hundreds or even thousands of kilometres along the coast in either direction, we might well get out of our car and find comparable sediments.

Beyond town, we can find more and different shells near the St. Andrews blockhouse.

On all the world’s coasts, the shells of molluscs and crustaceans occur in uncountable, utterly mind-boggling numbers. Counting them would be, literally, like counting the grains of sand on a beach or the stars in the sky. An examination of the geological record indicates that similar shelled creatures have been donating their remains to coastal deposits for more than 500 million years, contributing very significantly to the volume of sedimentary strata (and, incidentally, allowing immense amounts of carbon to be sequestered in the rocks). The scale of this invertebrate sedimentary contribution is entirely astounding; it is as big and as difficult to comprehend as the extent of geological time. Yet most of us, even many geologists, think about it not at all.

© Graham Young, 2017

What Geologists Share: Fieldwork and the Four Dimensions

December 27, 2016

If you visit this page occasionally, you will have noticed that I have posted very little since last spring. This interval correlates rather precisely with my term as President of the Geological Association of Canada. I have discovered that it really isn’t possible to be both an active blogger and an active officer of a national organization, and since the term of the president is just one year, I have been focused on that. As president, I am at least able to write articles for the GAC’s member newsletter, Geolog; this piece is reprinted here by permission.*

A group of geologists near Sloop Cove, Churchill, Manitoba. August, 2015.

Geological field party near Sloop Cove, Churchill, Manitoba: August, 2015

A few weeks back, during the golden days of early autumn, I did some collaborative field research in southwest Manitoba with colleagues from the Manitoba Museum. Spending field time with people from other disciplines, I began to consider our different thought patterns, patterns that have developed as a result of experience and training.

The zoologist was driving our van, but he was constantly scanning around for creatures as he drove. He could recognize the species and gender of a bird in flight before I could even see the bird, and he counted dozens of red-tailed hawks during a morning where I noticed maybe four of them. He detoured around snakes on the road and then stopped to ascertain their species, age, and sex.

Museum field party near Belmont, Manitoba: September, 2016

Museum field party near Belmont, southwest Manitoba: September, 2016

At a prehistoric bison kill site, the archaeologists could talk about the season of a hunt hundreds of years ago. They could envision the behaviour of people who drove the bison over a ridge and into a kill zone in the low wet rushes. We could see bits of bone everywhere, but they could find tools, know how the tools were made, and understand how the people were living and what resources they used. To me, it seemed like each of these non-geologist experts had their own “super power,” a quality that was beyond the ability of mere mortals.

As time progressed, I realized that we geologists also have our own super power. As we looked at older geological sites, it was striking that those of us doing geology could see things that our colleagues could not. Our background allowed us to readily place a series of long-past events in chronological order, and to “see” those events in the context of other things happening around them. We could see how the small modern Souris River sits in a valley that was eroded by much larger floods from the outflow of ice-dammed post-glacial lakes; high in the valley wall, those flows had cut through sediment deposited previously by a glacier, which had itself transported materials from the Cretaceous shales that sit lower in the valley. We could recognize this sequence, and we could keep the events and their locations in order in our heads; from their comments, our non-geologist colleagues clearly had a difficult time with this.

Banks of Cretaceous shale along the Souris River, western Manitoba

Banks of Cretaceous shale along the Souris River, southwest Manitoba: September, 2016

During many summers I have done fieldwork in the Churchill area of the Hudson Bay Lowland, and in 2014 and 2015 I worked there with groups of geologists that included people far outside my area of expertise. I am an invertebrate paleontologist, but these field parties included regional stratigraphers, sedimentologists, a petroleum geologist, and a Quaternary geologist. We certainly did not understand the details and technical terminology associated with one another’s specialties, but we all seemed to readily follow the other people’s thinking and arguments.

I have taken part in many other geological field trips, and geologists never really seem to have trouble crossing boundaries between one specialty and another. It seems that, at some point, most geologists have learned to apply similar logical thinking to a variety of geological settings and subjects (and this even holds true for those of us who started off in disciplines other than geology). The fact is that we all share a set of general principles: the geological time scale, uniformitarianism, the rock cycle, erosion, weathering, the law of superposition, the law of original horizontality, and the application of Occam’s Razor to our field observations. Walking around in the world, we all carry this basic information as a toolkit, and as a result we can see what other geologists are talking about, whether they are structural geologists, paleontologists, or geophysicists.

Dave Rudkin of the Royal Ontario Museum acts as polar bear guard for a group of geologists at Bird Cove, Churchill, Manitoba: August, 2015.

Dave Rudkin of the Royal Ontario Museum acts as polar bear guard for a group of geologists at Bird Cove, Churchill, Manitoba: August, 2015.

Field experience is absolutely critical to this understanding. At some stage we have all had to consider the world as a four-dimensional place; we look at the three physical dimensions of each geological site, considering what we can see on the surface and interpreting how it is likely to extend below that surface, but we are also constantly interpreting the changes through deep time that have produced what we see today. We visualize how overlying or crosscutting features can be teased apart to find the likeliest story. Basic geological field research, considering a variety of rocks and settings, gives all of us at least a modest understanding of the breadth of geology. It emphasizes to us that basic principles are important, and it encourages our interest to such an extent that many of those principles become fixed in our brains.

I am, however, concerned that geology is in some danger of losing that breadth. We hear so often now that we need to be teaching students to do very specific tasks, so that they will be trained for particular technical jobs – they need to know how to use very complicated and specialized equipment, how to log core in certain standard ways, how to carry out standardized studies that lead to particular defined research goals. This is important – there is no question that people need to make money and have careers, that our economy requires skilled and talented scientists, and that we constantly have a need for particular resources or that certain sorts of environmental problems must be solved.

Using specific equipment: me with a quarry truck near Churchill, Manitoba: August, 2016.

Using complicated or specialized equipment: me with a quarry truck, which we had contracted for some “serious collecting” near Churchill, Manitoba: August, 2016.

The danger in becoming an entirely “job-trained” modern discipline, though, is that we could also lose the vision that might allow us to solve future problems that we don’t yet even recognize. And the pursuit of very applied and directed work is likely to mean that scientists ignore anything they observe that was not included in the original workplan or grant proposal.

Lately, I have been reading some of the Geological Survey of Canada Reports of Progress that documented 19th century scientific exploration of Canada (I could say geological exploration, but many of them are so much more than that). Almost every field scientist employed by the GSC seems to have been a talented polymath, and as they carried out fieldwork in previously unexplored territory, they didn’t just look at geology. They observed and tried to understand everything, making incisive and generally accurate interpretations on the fly while canoeing many miles a day through often-hostile wilderness, collecting samples, mapping, and sometimes producing landscape paintings or photographs before sleeping under canvas. And then they did it all again the next day, and the day after, through the entire summer, perhaps making it back to “civilization” after the first snows of autumn.

gac-rept-1866-69

Those GSC scientists were, of course, given the task of locating and documenting deposits that might have economic importance. In the report for 1869, for instance, Robert Bell assessed silver resources along Lake Superior and Lake Nipigon, Ontario (Bell 1870), and Charles Robb noted molybdenum deposits in central New Brunswick, an area where mine projects are still being developed today (Robb 1870). While they were doing this, they also considered other questions they had been assigned, such as Bell’s discussion of where the transcontinental railway might be located in the area around Nipigon.

At the same time, the GSC field geologists documented many phenomena that had no obvious economic significance, simply because they were there and might become important in the future. The remarkable reports of J. B. Tyrrell hold many examples of this, such as his description of the Cedar Lake amber locality in Manitoba (Tyrrell 1892). Bell (1880) and Tyrrell (1897) both considered glacial geology as they spent time in the area around Churchill, Manitoba; this topic was far from most of their other geological work, but both made significant contributions to the development of ideas on postglacial rebound.

Pages from Bell's report on the Nipigon district (Bell, 1870)

Pages from Bell’s report on the Nipigon district (Bell, 1870)

These 19th century GSC geologists showed such remarkable drive, ability, stamina, and creativity, that most of us in the modern world are really just faint shadows by comparison. We may not be able to duplicate their energy, and the administrative and bureaucratic demands of the modern scientific world mean that we will never be permitted to have their focus, but we can still emulate their broad curiosity about all of geology and related disciplines.

As a museum curator, I feel very fortunate that many geologists do maintain this broad view of the world, since so much material in museum collections has come from such scientists. For example, a mining company geologist working with a drill crew in the Grand Rapids Upland was looking for an ore body, but was also interested in regional geology. I cannot speculate on what they found in terms of nickel and other metals, but he made an important paleontological find: he generously passed along to my colleague at the Manitoba Geological Survey that there were eurypterids (sea scorpions) in the Ordovician rocks in this area, and she in turn passed that along to me. As a result, we were able to go and scout in that same area, finding the site that hosts the strange and significant William Lake biota (Young et al. 2012).

Debbie Thompson (R) and me, carrying out paleontological field research at Airport Cove near Churchill: August, 2016 (photo: Michael Cuggy).

Debbie Thompson (R) and me, carrying out paleontological field research at Airport Cove near Churchill: August, 2016 (photo © Michael Cuggy).

As we travel around our country and the world, it is incumbent on us as geologists to always be using those tools that our training has given us. If it is my job to search for fossils, that doesn’t mean that I should be ignoring folds or minerals, just as a mining company geologist should not ignore the landforms beneath which an ore body might lurk. There are never enough of us in any one discipline in this huge land, and we all benefit if we are each considering the entire science as we travel around, not just our own little piece of it.

As a science, we always need to collaborate, to think of our colleagues, make use of our networks, and pass along any information that could be useful to someone else. This is, of course, a major reason why the GAC exists, and why our annual GAC-MAC meetings are so critical to the continued health of our science in this immense country. The geological integration of time and space is our super power. Let us use it wisely!

References

Bell, R. 1870. Report of Mr. Robert Bell on Lakes Superior and Nipigon. Geological Survey of Canada, Report of Progress for 1866 to 1869, pp. 313-364.

Bell, R. 1880. Report on explorations of the Churchill and Nelson rivers and around God’s and Island lakes. Geological Survey of Canada, Report of Progress for 1878-79, pp. 1C-68C.

Robb, C. 1870. Report of Mr. Charles Robb on a part of New Brunswick. Geological Survey of Canada, Report of Progress for 1866 to 1869, pp. 173-209.

Tyrrell, J. B. 1892. Report on north-western Manitoba with portions of the adjacent districts of Assiniboia and Saskatchewan. Geological Survey of Canada, Annual Report, Volume 5, Part 1, pp. 1E-235E.

Tyrrell, J. B. 1897. Report on the Doobaunt, Kazan and Ferguson rivers and the north-west coast of Hudson Bay and on two overland routes from Hudson Bay to Lake Winnipeg. Geological Survey of Canada, Annual Report of 1896, Vol. IX, Part F, 243 pp.

Young, G. A., D. M. Rudkin, E. P. Dobrzanski, S. P. Robson, M. B. Cuggy, M. W. Demski and D. P. Thompson. 2012. Late Ordovician Konservat-Lagerstätten in Manitoba. Geoscience Canada 39: 201-213.

*A version of this essay was originally published in Geolog (Vol. 45, No. 3, 2016), the quarterly newsletter of the Geological Association of Canada.

Golden Hour at Churchill

August 17, 2016

Scenes from Northern Summers (5)

rocks tree sea

In photography, “golden hour” is the interval just before sunset or just after sunrise, in which photographs are enhanced by the low angle and golden quality of light. Churchill, Manitoba, is a place where it is almost impossible to take a bad photograph, due to the sculptured, variable landscape and diversity of interesting life forms. Put golden hour and Churchill together, and even those of us with modest photographic skills can manage a few decent images. These photos were taken last night; we are in Churchill for paleontological field research, which has also been successful!

field and sea 2

field and sea 1

bar code road

Polar Bear Alley 1

Polar Bear Alley 2

Polar Bear Alley 3

Thiokol

A Thiokol snowmobile outside the Churchill Northern Studies Centre. This is clearly a remnant of US involvement in the Churchill rocket range; I wasn’t aware that the company that made rocket motors also produced snowmobiles!

© Graham Young, 2016

Meditation at 20,000 Feet

May 22, 2016

The following is lightly edited from notes written last week, as I travelled westward on a flight from Fredericton to Toronto.

9103 clouds

Across northern Maine and southern Québec, those ever-changing landforms are ghosts and memories. We cannot say that the Earth remembers everything that has ever happened to its surface – it has forgotten far more than it remembers, but it remembers a lot.

Every one of those features below us has a memory to tell, the story of how it was formed and how it changed through time – some of them are rich memories, full of detail and arc of story. Others are faded wraiths: you might just make them out if you look at them out of the corner of your eye, but they disappear when looked at straight on or in bright sunlight. Perhaps the dark arts of remote sensing, isotope analysis, and X-ray diffraction will divine their stories, but they hide their secrets deeply.

Wind generators on the Appalachians, along the Quebec-Maine border near Lac Megantic

Wind generators on the Appalachians, along the Québec-Maine border near Lac Mégantic

So many features, and so many of them are scars. Earth has had a long history of damage and injury – some of the injuries have come from outside, but some have been self-inflicted. Poor thing, our old Earth. We need to understand it better and treat it far better.

Walking with my brother earlier today, we compared injuries and war wounds – a chronically sore ankle here, an arthritic hip there. We commented that the human body might appear to heal, but it still carries the scars and damage within itself. That damage can rear up and reveal itself at some later date –  if we had known what we know now, we would have been more careful decades ago when we hurt ourselves.

Lac Megantic

Lac Mégantic

Earth is like that, too: many of its scars are not obvious to most of us. Those Appalachians we just passed over are one such scar – they tell us how tectonic plates crashed together oh so many years ago (starting about 480 million, actually), when Laurentia, the ancestral heart of North America, began to push into the crust of the ancient Iapetus Ocean (the continuation of this would eventually lead to the formation of Pangaea, as Laurentia pushed into northern Africa). In the process, Earth’s crust was buckled and pushed up into mountain ranges that, at their highest, may have been as tall as the Himalayas are now. Even Mount Katahdin, at a full mile high (including the cairn on top), is just a low remnant of those mountains. What happened to them? Earth may have self-harmed through plate tectonics, but it has been self-healing ever since through the use of weathering and erosion.

Earth started self-harming early on, apparently as a result of poorly resolved heat issues deep within. Plate tectonics began billions of years ago. The plates slowly move from one self-inflicted scar to another; the new crust rises at spreading centres (divergent boundaries) such as the mid-Atlantic Ridge, and crust is subducted and melted at convergent plate boundaries such as that along the Aleutian Islands. The scars are long and jagged, extending all around the planet’s face.

 

The sediment of the Lowland plain is cut by rivers. Note the characteristic Québec field pattern, with long narrow fields extending away from the waterways.

The sediment of the Saint Lawrence Lowlands plain is cut by rivers. Note the characteristic Québec field pattern, with long narrow fields extending away from the waterways.

You might argue that Earth is not really self-harming, that plate tectonics is nature’s course, and just the way a planet has to be. But other terrestrial planets aren’t like this. They have managed to grow up without plate tectonics (like Mars?), or they may have experimented with plate tectonics in their early years (like Venus), but later outgrew this juvenile deviance.

And sure, Earth self-harms, but at least that self-harm prevents it from showing many scars of external violence, unlike the Moon and Mars. All these bodies have been bombarded by meteorites, comets, and other space debris, most notably in their formative years – they all had a tough childhood. Earth’s self-harming may have allowed it to overcome that childhood damage – the scarring from plate tectonics effectively hides most of the pitting and damage from that external violence, except for a few places like the Manicouagan crater (which isn’t all that far to the northeast of us here).

Mont Rougemont is one of the Monteregian Hills. These igneous hills, which include Mount Royal and mont Saint-Hilaire, were formed as North America slid over a “hot spot” during the Cretaceous Period.

Mont Rougemont, rising out of the Saint Lawrence Lowlands, is one of the Monteregian Hills. These igneous hills, which include Mount Royal and mont Saint-Hilaire, were formed as North America slid over a “hot spot” during the Cretaceous Period.

Now we are out over the flat Saint Lawrence Lowlands. We could consider this sort of sediment-covered plain as being a “fully healed” patch of the Earth. The sediment has accumulated on and off over the past 500 million years or so. It blankets and hides the far less regular terrain beneath, including Logan’s Line where Appalachia and the Canadian Shield butt up against one another. Even below all that sediment is a scar that has never quite healed, as evidenced by the earthquakes that have occasionally struck Québec during the past few hundred years.

But wait. I can see some fresh wounds down there. Erosion never sleeps, and those valley sediments, even the relatively recent ones deposited under the Champlain Sea  some 10,000-13,000 years ago, are cut by fresh narrow rivers that knife through the surface and carry away the clay and soil.

Montreal and the Saint Lawrence River

Montreal and the Saint Lawrence River

Flying over Montreal, we see some of the most recent of Earth’s cuts and scars. But these are not self-caused; rather, they come from a parasitic infestation. The deep slicing of the St. Lawrence Seaway, the piling of stone on the side of Mount Royal, the piercings constituted by the Lafontaine Tunnel: these are not Earth’s own doing.

Will Earth’s scars and damage ever heal?  With enough weathering and erosion, all those hills would be flattened, rock fragments and clay would be transported away by rivers, and the entire surface of the planet would be a nearly level plain, probably located somewhere below sea level. But fortunately for all life, that won’t happen, because there is no evidence that Earth will ever cease self-harming. Even as I write this it is creating new crust along the ocean ridges, and pushing the Himalayas just a little bit higher. We can rest secure in the knowledge that tectonism never sleeps.

In case you are wondering, the blue arrow shows the approximate route of the plane over southern Québec. (based on Google map)

The blue arrow shows the approximate route of the plane over southern Québec. (based on Google map)

© Graham Young, 2016

Premium Real Estate

May 16, 2016
Periwinkles on a basaltic boulder

Periwinkles on a basaltic boulder

Those of us who study the ecology of long-extinct marine creatures have to work from clues: the morphologies of the fossilized organisms, the character of the enclosing sediment, and the preserved spatial relationships between fossils in bedrock. It is always pleasing to see modern examples that support our interpretations of ancient life. These photos from the shore of Passamaquoddy Bay show some very nice examples of the way in which many organisms need solid substrates.

Barnacles on sandstone bedrock

Barnacles on sandstone bedrock

In some sedimentary rocks formed on muddy or sandy seafloors, such as Manitoba’s burrow-mottled Ordovician carbonates, we often see fossil corals that had grown on top of other corals, corals that had grown on top of stromatoporoid sponges, and sponges that had grown on corals. In interpreting these we generally state that the distribution of the fossils was governed largely by the rarity of hard substrate. If the seafloor was covered with firm sediment, then the coral or sponge could have grown directly there. But if the seafloor was composed of soft or shifting sediment, then an organism there could not remain in a stable position, and it was only those that found firmer substrates that were able to survive. Thus, we see the corals and sponges that had grown on other corals and sponges, as those were the only hard surfaces around (whether the overgrown creatures were alive or dead at the time is a whole other avenue of inquiry).

The Saint Andrews shore, with Deer Island on the horizon

The Saint Andrews shore, with Deer Island on the horizon

Read more…

An Embarrassment of Riches

March 22, 2016

World Water Day, 2016

Flying over Manitoba's Hudson Bay Lowlands in a helicopter, the tundra ponds cannot be counted.

From a helicopter, the tundra ponds in Manitoba’s Hudson Bay Lowlands are countless.

As World Water Day draws to  a close, here are a few images illustrating a fraction of Canada’s immense store of fresh water. World Water Day brings to the fore humanity’s concerns about fresh water, health, and environment. Canadians need to be far more aware that Canada holds about 20% of the planet’s freshwater resources; this water is critical not only to our population and industries, and to our marvellous wilderness and ecosystems, but also to the global environment.

These photos were all taken during my travels in the past year.

New Brunswick's Saint John River changes dramatically from season to season. In Fredericton in the dead of winter, it is a sahara of snow . . .

New Brunswick’s Saint John River changes dramatically from season to season. In Fredericton in the dead of winter, it is a sahara of snow . . .

. . . while during spring freshet the river below Fredericton fills most of its valley . . .

. . . while during spring freshet the river below Fredericton fills most of its valley . . .

Read more…