Potential industrial clays of Alberta : a preliminary assessment, Part I

In Alberta most rocks older than the Kootenay Formation (Jurassic - Lower Cretaceous) are unsuitable for ceramic purposes because of their coarse-grained, siliceous, or carbonate natures. One hundred and eighteen samples of the younger shales, mudstones, or clays were tested from 51 easily-accessible locations. Clays from the Luscar Formation show the most potential as they work well, extrude well, and dry well in addition to firing to an appealing dark chocolate colour at the end of a moderate firing range. Moderate potential exists for Kootenay, Dunvegan, Brazeau, and Paskapoo Formation clays if they can be blended with other clays to improve drying and firing characteristics. Little potential exists for Blairmore Group, and Kaskapau, Wapiabi, Horseshoe Canyon, or Porcupine Hills Formation clays because of poor drying characteristics and short firing ranges. Pleistocene lacustrine clays generally dry poorly and have a short firing range. A deposit of Pleistocene clay from the Edmonton area, which has better than average drying characteristics and which has firing characteristics that are improved with the addition of prefired clay "grog," is used in brick manufacture.