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This is a "badlands" slope in the Frenchman river valley. The valley exposes the "Whitemud Formation" in many places (clearly visible here half way down on the left). Two surface mines of Plainsman Clays are nearby (over the top and down the other side), in a place where lower-lying rolling hills leave much less over-burden to remove. These materials were laid down as marine sediments during the Cretaceous period. The skeleton of the world's largest T.Rex, dubbed "Scotty", was found 50km east of here (in the layers just above the Whitemuds). Where are the layers of Scotty's ancestors from the Jurassic period? Straight down until you hit the bed rock!
During a 6 week of mining in 2018 in Ravenscrag, Saskatchewan we extracted marine sediment layers of the late Cretaceous period. The center portion of the "B layer", as we call it, is so fine that it may have been wind-transported (impossibly smooth, like a body that is pure terra sigillata)! The feldspar and silica are built-in, producing the glassiest body surface I have ever seen, starting at cone 4 and lasting to cone 8. Despite this, pieces are not warping in the firings! I have not glazed the outside of this mug for demo purposes. I got away with it this time because the Ravenscrag clear glaze GR6-A is very compatible (the thermal expansion is high enough to avoid glaze compression issues and low enough not to craze). With other less compatible glazes these mugs cracked when I poured in hot coffee. To make this body I am slurrying it up as a slip and processing it to 325 mesh (using a vibrating sieve).
These amazing hills near Big Muddy, Saskatchewan expose the sedimentary layers of the Whitemud formation (and others). The light-colored layer at the bottom is what Plainsman Clays calls A3, it makes up about half of M340. But below ground is the 3B layer, the other half. The dark grey layers above the Whitemuds are what we call A2, a ball clay. Top soil has accumulated on much of the clay to be able to grow the grass but there are bare spots around these hills. Although this is about 250km east of the Plainsman quarry at Eastend, Saskatchewan - the clay layers are remarkably similar. The clay resources in the area are truly astounding, not just in the quantity and quality but also in the magnificent landscape they define.
Eastend, Saskatchewan is the location of the incredible T.rex Discovery Centre. It hosts Scotty, the world's largest T.rex. The building is an architectural marvel and the exhibits are on par with anything else where. The building is actually embedded into the hillside in the same geological layers in which the fossilized skeleton was found, the Battle Formation (just above the Whitemuds that are mined by Plainsman Clays). If you ever get a chance to drive from Ravenscrag to Eastend take the south road for the most dramatic views. Do it in the spring when the grass is green. The sheer scale of the valley, the land formations and the countless outcrops of the Whitemud clays will amaze. At Eastend, have lunch at Jack's Cafe and socialize with the locals, you won't be disappointed! Then go and see Scotty.
These mugs are made from clay mined from the Whitemud formation in southern Saskatchewan. Those layers date from the late cretaceous, the worlds largest T.Rex was found nearby. The errosive forces of nature during that period did a marvellous job of purifying and depositing this beautiful high temperature stoneware clay. It is basically complete right out of the ground, with just the right amount of feldspar and silica added to a ball clay and kaolin base. The glaze on these is G2571A bamboo, the engobe under it is L3954N black. They were fired at cone 10R. These are examples of mugs I make and catalog, each has its own pedigree web page that celebrates every detail about the materials and process used to make it (e.g. here is a pedigree page, it links to the mug's store URL). However please don't attempt to buy any, I am using the store as more of a gallery for now.
Articles |
Ravenscrag Slip is Born
The story of how Ravenscrag Slip was discovered and developed might help you to recognize the potential in clays that you have access to. |
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URLs |
https://www.royalsaskmuseum.ca/trex
T.Rex Discovery Centre |
URLs |
https://en.m.wikipedia.org/wiki/Whitemud_Formation
Whitemud Formation at Wikipedia |
Glossary |
Plainsman Clays
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