Posts Tagged ‘geography of Canada’

Cave shaft – Canada, originally uploaded by Mic2006.

In the same area where we discovered the Tooth Tube, a cave that we have been clearing of a glacial plug of clay, we have also found numerous deep shafts, aligned along joints they tend to be deep and narrow with fluted sides and moss around their upper lips. To a caver, a cave shaft is generally indicative of something that might be occuring lower down. Often, but not always, the shaft represents the dominant passage of water as it drops beneath the surface, and as Marcus Buck had pointed out in the excavation of the ‘Birth Canal’ at Olmstead in the Eramosa Karst, “Usually if you follow where the water goes, it takes you on to tunnels”.

This particular field of shafts and pits is in an area that is not too far north of Toronto, Ontario , Canada. For a Torontonian I believe it is one of the coolest things to do near Toronto.

The shafts that we found occur in a plateau that sits well above a large body of water and though the local water table is sometimes known to be perched, it would appear that by looking down into some of these holes, it must still be way below the surface. Many of the more slender shafts appear to be relatively debris-free. Wider shafts tend to be clogged with soil and leaves and logs. They can approach a diameter of about 10 feet in width and we speculate that like in the St. Edmunds System, water may have entered the underground at a time when the area was beneath a kilometer thick sheet of ice. As the pressure head built up, the water beneath the glacier was forced down tiny crevices, down to the bedding plane, and then out at the base of the plateau. Most of these shafts are at the bottom of a conical depression of between 10 and 25 feet in depth. In an old manuscript Martin Davis mentions a stream that he had dye traced that seems to take most of the surface water from this area and drains it out at a single point in the cliffs around the edges of the plateau.

Strings of shafts line up along the general orientation of local joints and we intend to plumb the depths of one such shaft this weekend. Our best case scenario is to find an open cave tunnel that requires minimal digging to clear it. I dropped a bolder down one deep shaft where I could not see the bottom and after an impressive pause I heard the muted ‘thunk’ of tin that had been pounded by my falling missile.

In one relatively shallow shaft we have found a crevice that seems to drop down into a water worn passage beneath, that will be our first priority. It was hard to get a good look at the passage as the crevice above still requires some cleaning, but I had the distinct impression it was human sized and floored with cobbles like we found in the Wasteland Waterway – still to be pushed to its endpoint.

For a final look at where we got with our excavation on the Tooth Tube – Click for cave video of the Tooth Tube here.

Check out the shaft at C-H sink, it is also in an area where sinks dimple local fields. Check out a short video of the C – H sink here

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