|Monthly Tech-Tip |
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.
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!
Layers of the Whitemud Formation are being mined. The layer being extracted is a silty stoneware they referred to as the "D member" (equivalent to Plainsman 3D which is mined several miles to the east for use in pottery). Below the D they continued to mine a much whiter kaolinized sand of equal or more thickness. Above the D is a ball clay (equivalent to Plainsman A2). Above that is a light-burning stoneware (the combined layers that Plainsman extracts separately as A3 and 3B). A foot-thick layer of much harder volcanic ash is visible in the green overburden at the top. From these stoneware clays they extruded brick of exceptional quality, firing it as high as cone 10. Twenty years later the company reclaimed this land and today you would be unable to find where the quarry was located.
Eastend, Saskatchewan hosts 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 a meal at Jack's Cafe, you won't be disappointed! Then go and see Scotty.
T.Rex Discovery Centre
Whitemud Formation at Wikipedia