Oxford clay

Ross, C. A. M., Bath, A. H., Entwisle, D. C., Cave, M. R., Fry, M. B., Green, K. A., and Reeder, S. (1989). Hydrochemistry of Pore Waters from Jurassic Oxford Clay, Kellaways Beds, Upper Estuarine and Upper Lias Formations at the Elstow Site, Bedfordshire. WE/89/28, British Geological Survey. Keyworth, Nottingham. 

Hudson J. D., Coleman M. L., Barreiro B. A., and HoIIingworth N. T. J. (2001) Septarian concretions from the Oxford Clay (Jurassic, England, UK) involvement of original marine and multiple external pore fluids. Sedimen-... 

Jurassic 145 Oxford clay. Fuller s earth Limestone, gypsum, calcareous sands and grit, jet and lignite ... 

Reactions similar to those taking place in the calcination of pure clay minerals also take place in the production of ceramic bricks and tiles in industrial kilns, and these products also exhibit pozzolanic properties if crushed to a fine powder (Ranogajec and Fisang, 1992). In experiments performed with Lower Oxford clays it was found that samples fired to 600-800°C still contained substantial amounts of residual illite, whereas in those burnt at 900-1100°C an amorphous glass phase was present that exhibited a distinct pozzolanic activity (Wild et a/., 1996b, 1997). 

A continuous stripper working the Lower Oxford Clay at Whittlesey, near Peterborough, England. 

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. 

Knotts. Term sometimes applied to the Lower Oxford Clay used for brickmaking in the Peterborough district, England. 

Ever since the first landfills became operative in the UK in 1912 (Hasan 1995), leachate has been an environmental problem. These landfills exploited soils and rock formations rich in clay, relying upon their natural characteristics for the containment of contaminants present in the leachates. Due to the low permeability of the clay minerals they contain (1 x 10 and 1 x 10 cm/s), formations such as the Oxford Clay in the UK and Fort Benton in the USA were the primary target of landfill engineers. It was hoped that clay minerals present in situ in rock formations underlying the chosen landfill sites would reduce the flow of leachate. In addition, the clay formations were relied on to attenuate the potentially harmful substances contained in the leachates by a variety of sorption processes absorption, adsorption and cation exchange. 

Oxford Clay Brogborough landfill site, Woburn, Bedfordshire Shanks and McEwan Ltd... 

Of the seven test materials initially selected, slate spoil and the red Coal Measures Clay were rejected for use in the column experiments. This was because preliminary compositional analysis indicated that the effects of their range of properties (e.g. CEC, organic carbon content, pH buffering capacity) could be adequately investigated with the remaining substrates. Selected geochemical properties of the materials subsequently used in the column experiments are presented in Table 5. These illustrate the compositional diversity in the suite of materials tested which includes substrates possessing one (e.g. Chalk), several (e.g. BCMC, Oxford Clay) or none (e.g. quartz sand) of the key properties of interest. 

Fig. 4. Breakthrough curves for selected inorganic solutes from a 10% Oxford Clay-90 % quartz sand column experiment.

This work was completed with financial support from the UK EPSRC under grant GR3/F87233. H. Robinson and Aspinwall Co. are thanked for providing site access for leachate collection. Shanks and McEwan Ltd are also thanked for providing site access for collection of the Oxford Clay samples. 

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