Ancient Glacial Shorelines Here in Meaford

The last post I'm going to do in this short series is one I've been thinking of for a long time, and that is the ancient glacial shorelines that run through Meaford, one of them passing  just a couple of blocks from where we live.   These are just things that fascinate me, hills that I see as we drive or I ride around town that intrigue me.

The first is the Nipissing shoreline, dating from about 4000 years ago, when glacial lake levels rose again following the very low Lake Stanley episode.  This shoreline is found around much of Lake Huron and Georgian Bay, if you know what you're looking for.  The waves on lakes abutting a gentle hill will cut into that hill, carrying sediment away and leaving a relatively steeper bluff behind.

This is my crude attempt at drawing the Nipissing shoreline as it passes through Meaford, with apologies to my readers from out of town.  It starts in the east end forming the north edge of Lakeview Cemetery, as anyone who has been there will recognize.  It wiggles a bit where the Georgian Trail cuts through, and forms the long hill up Sykes Street.  If you take the back road it's behind houses on the south side of Edwin Street. and curves around to hit the Bighead River.

Shortly up the Bighead it's represented by the rapids where the river has cut through, and then it curves around forming the south side of the bluff where the hospital sits - Hospital Hill they call it.  Then the old shoreline curves around west of the Community Centre and Arena, the fairgrounds and continues north.  In so doing it crosses Collingwood St., the hill I ride down when I ride downtown.

Last spring, before the leaves were out I stopped at the short dead end of Berry Street, just north of the river and south of the hospital.  This view is looking directly west at the dead end, up that steep hill.

Slightly to my right was this view, the forested slope across someone's lawn, a corner of the hosital visible at the top.

Partway back out that short street you can look up to where the water tower and helicopter landing pad for the hospital sit.  I left the garage in for scale and perspective.

The ancient Algonquin shoreline is another story.  It isn't visible passing through town, but rather wraps around town, extending in a confusion of slopes up into the Bighead Valley.  This was the level  established about 9000 years ago as the glaciers first retreated, the same age as those hunting structures on the Alpena-Amberley Ridge, deep under Lake Huron.

Perhaps the easiest place to see the Algonquin shoreline is on Grey Road 7 when you're heading south at the east end of town.  The hill at this point is certainly big enough that you can't miss it.  It's much larger than the hills associated with the Nipissing shoreline.

And of course you see that hill again when you drive back down it into Meaford, one of our beautiful views over the bay.  So there you have it, ancient glacial shorelines at a very local scale here in my hometown.  Having put this together I can think of several other photos I'd like to get, and more information I'd like to find, especially about the Algonquin lake level.  Perhaps then I'll write a more comprehensive post about this.

The Indigenous Legends

 Now that you know about the discovery of ancient indigenous hunting sites of the Alpena-Amberly Ridge, lets move a little east and look at the stretch of water between Tobermory and Manitoulin Island.  Tobermory sits at the northernmost tip of the Saugeen (Bruce) Peninsula, and is known for its offshore islands and shipwrecks (two right inside the harbour).  The area is now encompassed by the Fathom Five National Marine Park.

The Niagara Escarpment that creates the eastern shore of the peninsula continues as the east shore of these islands, all the way to Manitoulin.  And with divers exploring 24 shipwrecks, scientists have discovered both ancient tree stumps and a gigantic submerged 'waterfall'!

This map is intended as a wall hanging, but it's the best I've found to show the location of that ancient waterfall, in dark blue.  This waterfall formed during that Lake Stanley phase of the Great lakes, and necessitated a river flowing from Lake Stanley to Georgian Bay, creating this waterfall.  

In those ancient days there would have been an actual waterfall, said to be larger than Niagara Falls today, but of course now that it's submerged, there isn't any water that's actually falling.  The white somewhat triangular-shaped island where the deeper water channel seems to begin is Flowerpot Island, where our family camped in about 1967.  I never dreamed a big waterfalls was just offshore!

We get a different view in this bathymetric cross-section, the peninsula on the left, and Manitoulin on the right.  The river channel leading to the falls is clearly shown, leading to that deep plunge pool offshore.  There's a secondary river and waterfalls on the right hand side, between Fitzwilliam Island (the arrow-head shaped one) and Manitoulin.

I'm just blown away to learn this and see the diagrams, since we once had a cottage on Manitoulin, and made the trip by ferry at least 40 or 50 times, as well as visiting Flowerpot Island.  

At the lecture that sparked these posts, one of the things Lenore mentioned was ancient legends of the elders from Neyaashiinigmiig (commonly known as Cape Croker), the closest community of the Chippawas of Nawash that suggested a land bridge between the peninsula and Manitoulin.  I'm not sure it would have been a 'bridge' as we understand the term, but there was certainly a lot of dry land around the islands.

Returning briefly to the research on the Alpena-Amberley Ridge, as well as the drive lanes that the researchers discovered, the divers took samples of the soil and remaining vegetation they found.  By bringing up samples of the sediments and analyzing them, they built a picture of this ancient landscape.  

Professor Lisa Sonnenberg of McMaster University, led the analysis, finding that this ridge would have had small trees and shrubs interspersed with wetlands, giving the appearance of today's today's Hudson Bay  This is one of the stumps they found.

It's not too big a surprise then to read that National Park researchers have encountered stumps in several location in Georgian Bay.  This is another of those stumps.

"Chippewa elders of the Cape Croker reserve have long repeated ‘legends’ of their ancestors being able to walk from Tobermory, at the Northern tip of the Bruce Peninsula, to Manitoulin Island, an area that, today, is covered by 90 km of water,"  I guess it's true!

The Alpena-Amberley Ridge

At this point in understanding ancient Great lakes history, we will focus on the Alpena-Amberly Ridge under the middle of Lake Huron.  If you don't know what this is, you'd better go back and read the previous post.

About 20 years ago, Dr. John O'Shea, an archeologist at the University of Michigan, was looking at this bathymetric map of Lake Huron, and spotted that shallower ridge running from southeast to northwest through the lake, here highlighted by black dashed lines.  It came to be known as the Alpena-Amberly Ridge, for the names of the nearest towns on each end, and it has been a focus of underwater archeology ever since.

There have been lots of advances in underwater exploration in recent years, usually from trying to find shipwrecks, so there are good tools for underwater archeology.  O'Shea took advantage of these and initially used side-scan sonar, finding evidence of rock piles that appeared human-made.  

Caribou are known to travel in regular routes, based on patterns in today's Arctic.  There indigenous hunters build small rock cairns creating 'drive lanes', making hunting more successful.  We once crossed one of these hunting spots, while paddling down the Burnside River in the Arctic.  A pile of antlers bore witness to the successful hunt.

Next they used a remotely operated vehicle which they named 'Jake', as well as actual divers to assess the appearance of this ridge.  The structures they found looked like drive lanes which could have been used to funnel the animals by creating bottlenecks where Indigenous hunters would be more successful.  They also found hunting blinds and broken arrowheads.

This description also immediately reminded me of Head-Smashed-In Buffalo Jump in southern Alberta, a site we visited on our first big trip west with our kids in 1986.  People visiting this site are of course entranced by the cliff the buffalo jumped over, and the kill site below.  Even archeologists focus on the kill site, because that's where you find ancient artifacts.  

But the real action took place above the cliff.  Here men of the tribe placed rock cairns built up with sticks and brush to create long drive lanes that the buffalo followed.  The real work was in finding a convenient herd and gradually working them toward these drive lanes.  (It was a lazy young brave who hid below the cliff rather than join the runners who had his head smashed in).

In this, another version of a bathymetric map of Lake Huron, you are looking at the Lake Stanley phase of the Great Lakes, approximately 7000 - 9000 years ago, when the Lake Huron basin was divided in two, and water levels were much lower than today.  The Alpena-Amberley Ridge stands out clearly.

The research led by underwater archeologist Dr. O'Shea has discovered an ancient caribou route across this dry ridge.  And further, it has documented stone structures built by indigenous hunters at narrow points of the ridge and what appear to be hunting blinds.

The research was not over yet though.  By gathering sediment and analyzing it they were able to reconstruct the ancient landscape, or what they labelled the paleo environment.  That's the next story.

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Caribou Hunting in the Great Lakes?

We attended a fascinating lecture at our regional museum last week, and it's got me interested in ancient Great Lakes history.  So I'm doing a little research of my own and I'm gonna share it with you over a few posts while we wait for the endless cold temperatures of early April to go up!

Leonore Keeshig, of the Saugeen Ojibway First Nation, spoke on indigenous legends that tell the story of retreating glaciers and a time when the annual caribou hunt was important, in a landscape that would be described as arctic, about 9000 years ago.  It was a landscape that would befie your belief today as you sail over the waters of Lake Huron and Georgian Bay.

So bear with me while I give you some background and then I'll try to explain the essence of her message.  Otherwise you can just skip this post and wait for the next one.  I hope you can get used to these maps.  They're kind of skewed, with north in the upper right corner but I'll explain them.

The upper left corner of this widely published diagram, shows the glaciation of the Great lakes, when lobes of the continental ice sheet extended down into Lake Michigan and Lake Huron.  Two lakes of meltwater sat in the south end of today's Lake Michigan and Lake Erie, labelled by scientists as Lake Chicago and Lake Maumee.  Drainage was to the southwest, through Saginaw Bay and Chicago to the Mississippi.

In the upper right diagram, the glacier has retreated north, allowing for a huge glacial lake to form, encompassing both today's Lake Michigan and Lake Huron, and the tip of Georgian Bay, labelled glacial Lake Algonquin.  It still drained to the southwest, as drainage north or east was blocked by the ice.  The shoreline of that lake can still be traced, considerably higher than the lakes today, including right here in Meaford.

The lower left diagram is the interesting one.  As the ice retreated north the lakes reached a point where they could drain to the northeast, out through today's French River and North Bay, reversing the drainage pattern completely.  This left the glacial lakes at a much lower level than today's lakes.  A smaller lake occupied Lake Michigan, known as Lake Chippewa, and similarly a smaller lake occupied Lake Huron, known as Lake Stanley.

It is at this stage, somewhere between 7000 and 9000 years ago, that we find tantalizing evidence of indigenous life on dry land that is today submerged.

Let me first finish describing the diagram above.  In the lower right corner we have a map showing approximately today's Great Lakes.  The water level was a little higher, so the Lake Huron/Georgian Bay/Lake Michigan basin was inter-linked and known as Lake Nipissing; Lake Stanley has disappeared, but there is still drainage to the northeast, through North Bay.  We can find clear evidence of this old shoreline right here in Meaford; indeed, it's just two blocks from my house.

Let's take a closer look at that Lake Stanley and the lowest water levels of the Great lakes basin.

I had always assumed that the glacial lake levels were much higher than today's lake levels, and they gradually fell, from glacial Lake Algonquin to Lake Nipissing to today's lakes.  But it's not actually that simple.  Glacial lake levels actually fell to a very low level, as in Lake Stanley, and then rose again to the Lake Nipissing level, and then fell again to today's lake levels.  So we have a gigantic up and down pattern going on.

When drainage shifted to the northeast, the lowest levels of the lakes were reached, with rivers connecting Lake Chippewa, Lake Stanley, Georgian Bay and a small corner of what became Lake Superior.  The green areas here were dry land, extending the shoreline far out from today's pattern. 

Take a look at how the Lake Stanley basin was divided in two.  Turns out that band of green running through the middle of the lake was dry land too, an underwater ridge known today as the Amberly to Alpena Ridge.  That's where we'll pick up next post; hope you're still with me!

The Snow Cycle Continues!

 Yes, it is still March today as I write this, and March never knows whether it's ready for spring or still has a bit of winter left to visit.  And so we had yet another gentle snowfall overnight last week, continuing what seems like a never-ending cycle.

It was only a couple of inches, but it turned the world briefly white again.

Our crane/snowstick got to do its work for a change.

Remember those white Hellebore; they got another dose of cold therapy.

And the Daffodil shoots out front didn't even seem to notice!

But I'm happy to report that things are now back to normal, and the only bit of snow left is down in the lower left corner, in the shade of the house.

And the Hellebore survived again, raising their blooms to a rainy late March day.  The dangerous ice storm the forecast warned us of ominously hasn't materialized yet.  But we did lose power at an awkward stage as they were attempting to get me out of bed.