Keuper marl

Marls like keuper marl such as marble 20 10 to 30 5 to 300 -... 

Mesozoic (or Secondary) Triassic 170 Keuper Marl Bunter sandstone, pebble beds, Keuper Sandstone, gypsum... 

Chandler, R.J. 1969. The effect of weafhering on the shear strength properties of Keuper Marl. Geotechnique, 19, 321-334. 

Gotham Corby Keuper marl Cinders 77 89 21 Not tested 17 b... 

Brick Clays. Clays suitable for the manufacture of building bricks occur chiefly in the carboniferous and more recent geological systems. In the UK about 30% of the bricks are made from carboniferous clays, 30% from the Oxford clays, 10% Glacial clays, 6% Keuper Marl the remaining 24% are made from Alluvial clays, the so-called Brick-earths, Tertiary, Cretaceous, Devonian, Silurian, and Ordovician deposits. Brick clays are impure and most of them vitrify to give bricks of adequate strength when fired at 900-1100 = C. 

Gypsum. Natural hydrated calcium sulphate, CaS04. 2H2O, from which PLASTER of PARIS (q.v.) is produced. In England gypsum occurs in the Newark and Tutbury zones of the Keuper Marl, and in the Purbeck Beds of Sussex. It occurs abundantly in USA, Canada, France, USSR and elsewhere. 

Sepiolite. 3MgO.4SiO2.SH2O the magnesian end-member of the series of clay minerals known as palygorskites (q.V.) it has been found in some of the Keuper Marls used for brickmaking in Central England. 

Stock Brick. Originally a term localized to S.E. England and meaning a clay building brick made by hand on a stock , i.e. the block of wood that defined the position of the mould on the moulding table. Stock bricks are now machine-made. The London Stock Brick is a yellow brick of rough texture. The term stock in the sense of usual , is sometimes applied to bricks of other areas, however, e.g. a Lincoln Stock is a semi-dry-pressed brick from the Lias. A Belfast Stock is a pink wire-cut brick from the Keuper Marl. 

Already in the first half of the nineteenth century, the Gemian engineer-geologist William Schulz refened to the iris of the Keuper marls and mentions that "at the top of this fomiation are often found gypsum banks" (Schulz, 1838). This author was a pioneer in... 

Worcester series. Red silt loam (or silty clay loam) formed from Keuper Marl and found in the East and West Midlands and in the south west. They are slow-draining, require subsoihng regularly and are best suited to grass and cereals. 

Honeyborne, D. B., 1951. The clay minerals in the Keuper Marls. Clay Min, Bull, 1 150-157. 

Stephen and MacEwan [1950, 1951] have found in the Keuper Marl near Birmingham a partially swelling material analogous to illite, but having chlorite as its major component. The X-ray diffraction patterns shows a broad band toward smaller angles, with a cutoff near 13.8 A. On heating, the latter spacing sharpens. No specific name was proposed for it. 

Figure 29. Differential thermal curves for 4—montmorillonite, Camp Berteau, Morocco B and C—two pseudochlorites prepared from Camp Berteau montmorillonite D—natural pseudochlorite, Angevillers, Lorraine, France -natural (impure) pseudochlorite from Keuper Marl (Caillere and Henin [1957a]).

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