This week I pooled all of your world ‘regionalization’ maps and gave a brief tour of your aggregate divisions of the world into various kinds of regions, based on climatic factors, cultural attributes, economic differences and ideologies, etc. There were some very interesting divisions that you all mapped, though I think it is useful for me to emphasise, that this exercise was not about accuracy so much, but rather just to get us into the mode of thinking about how ‘humans’ construct our worlds in these various compartmentalizations – regions, because it makes sense for us given how big and complex the world is.
This was done to help understand the rationale for the coming lectures on the Grand River region – i.e., as an example of a ‘region’ with a distinct landscape setting -- biophysical features and history, and a region where the various cultural, political, economic, and environmental 'stories' or spheres are linked across time within this place. And yet, in keeping with the region definition, we also see that there are differences across the watershed with respect to those same 'spheres', and various connections to areas beyond the region itself.
I think it is important to recognize, as emphasised in class, that regions are
not 'absolute' -- they are dynamic and are a consequence of the various ideas
that individuals and societies may use to decide on a 'region'. These regions
change over time as a result. Political, cultural, economic conditions and
attributes of places change over time, and thus our sense of their ‘unity’ or
distinctiveness as a region does as well. However, there is usually enough
stability of the 'region' relative to the presence of human groups there and
the criteria often used to decide 'region', to claim that these areas form
regions with some credibility – at least over the short to medium term. For
example, most of us accept Canada as a region, but it really only has been
formally present as a political region since 1867, and even then it did not
formally include much of the land mass that we now take for granted in the map
Note: As we work through the coming material on the Grand River, you will note how your ideas about this region, and how we regionalize, change – i.e., we become more conscious of the attributes of this place, which make it distinct from others. Think through some of these, as you will need to be commenting on the concept of the 'region' during the mid-term exam and for your presentation in tutorial and the final written paper which comes out of that presentation.
I then began to look at some specific kinds of physical regional features associated with the Grand River region, and I’ll throw in a few notes here I did not go into detail on in class.
These underlying physical regional traits are important in the sense of not only forming the base geological context for this region, but also the soils, vegetation, drainage pattern, relief, glacial till aggregates (gravel and sands, etc.) which were and have become important resources in the development of the economic and cultural systems and conditions of the watershed as we know them today.
- Landforms/physiography of region are result of two big forces – the underlying geology, & glacial activities of past
- Canadian Shield – massive, old pre-Cambrian bedrock underlying all of Ontario and further south into the US (mostly granite, 3-4 billion yrs old)
Canadian Shield once a vast mountain chain à from Kingston thru Sudbury up to James Bay and further west – Manitoba, Sask, up into Territories: bigger & more rugged than Rockies – but bec they’ve been around for so long, they’ve been eroded & weathered considerably
à snow & ice broke them up & their materials moved by water flow and gravity over the eons, down to lower areas like S. Ontario & further south -- courser materials settle out as faster-flowing waters slow down, but clays only deposited in lake & sea environment
You can likely see how the Silurian sedimentary ‘unit’ is the one most closely underlying the GR region.
Note: I have cut and pasted some notes from the lecture here which I won’t normally do, but that will provide some background that some geology text might have for our purposes here.
The I went through a bunch of slides on the coming and ‘retreat’ (recall that glaciers don’t actually back up, they just start to melt) of the Wisconsin Ice Age, and all the stuff that that period left behind on top of the bedrock underneath – being a fairly significant factor on how stuff looks out there on the landscape – and for instance, playing a big role in guiding the direction that water flows – e.g. the GR.
GLACIATION HISTORY & IMPACTS
Last ice-sheet Wisconsin – 120,000 to 10,000 yrs b.p. [before present] … important because of carving out of GR watershed, & of the stuff (various tills and glacial formations) deposited or lain down over the bedrock leaving the landforms we see.
Boulders, Cobbles, Gravels, Sands, Silts, Clays à different grades of tills assoc with rates of water flow over, through, or outwash from glaciers; or in relation to movement & parts of glacier (sides, end, etc.)
Morraines – various types/mix of deposits assoc with the glacial lobes and the material pushed in front or left along the sides
Great Lakes – carved out over course of many glacial periods
Drumlins – material deposited in direction of glacial mvmt.
‘Chatter-marks’ – bouncing of little rocks underneath glacier on surface of rock as glacier moves along
Eskers – sand & gravels dropped from rivers flowing within & below the ice
“striations” – glaciers pushing rocks across rock
Erratics – the old detritus chunks moved here from where they were scooped out further to the north (often Canadian Shield granite)
Kettle-Lakes – where huge old chunks of glacier were left behind and melted into a deep ‘kettle’ lake formation
In the Grand River Area we see things like lengthy sections of moraine left as part of landscape post-11000 yrs ago when the ice-lobes of this area melted (retreated…)
These above glacial remnants can be quite significant features, and the map right here gives some idea through the brownish elongated strips which represent the ‘morraines’ of various sorts that are part of the landscape now, and which can be seen in various parts of the watershed – drumlin fields around Guelph, the odd pockets of little lakes and ridges which run from Paris up to Guelph for instance, and the big moraines up in Waterloo area of the watershed.
Note: I will take some of the notes where I was looking at the attributes of the GR watershed, and couple them together with the stuff I have cut and pasted from David Morris’ lecture on Carolinian Canada, in the Week Three notes link.