Clayey limestones

The carbonate content of mudrock interbeds averaged by formation ranges from 17 to 59% (the latter are more properly clayey limestones) (Table 3), about 3-10 times the amount of carbonate in sandstones. There is no correlation between the amount of carbonate in sandstones and associated mudrocks, but formations whose sandstones have abundant detrital carbonate grains generally have... 

Burki and Braun (1988) asserted that the clinker structure from laboratory tests is principally determined by raw meal properties and to a lesser extent by the heating rate. Rapid heating was said to increase the alite formation rate, accelerated with a homogeneous raw meal made of a chalky, clayey limestone (cement rock). A coarse microstructure (large voids and large crystals) was produced from coarse meal made largely of monomineralic particles. No influence of the final size of the alite and belite was observed after variations in heating rates. 

Perhaps the best place to start the discussion of cement standards is with a definition. Natural cement is currently defined in ASTM C 219 as a hydraulic cement produced by calcining a naturally occurring argillaceous [clayey] limestone at a temperature below the sintering point and then grinding to a fine powder [1]. 

Alumina in combination with siUca is present in limestone chiefly as clay, though other aluminum siUcates in the form of feldspar and mica may be found. When present in appreciable quantities, clay converts a high calcium limestone into a mad or argillaceous stone, which when calcined yields limes with hydrauhc properties. Limestones containing 5—10% clayey matter yield feebly hydrauHc limes those containing 15—30% produce highly hydrauHc limes. 

Mangrove Forest ecosystems occur on the surface of compact cavernous reef limestone or on carbonate sands, aleuritic and clayey silts in lagoons and shallow... 

Abrasive coasts are mostly composed of clayey deposits, poorly-cemented rocks, or limestones. The cliff heights range from 15 to 35 m. The abrasion rate is controlled by the composition of the coastal rocks and the cliff heights. The recession of the cliffs is also caused by the development of landslide and caving processes, especially under the conditions of strong storms. The length of individual sliding blocks reaches 500 m at a width of up to 15 m. Deep surf niches are formed in the lower parts of the cliffs. 

Very simply, a sandstone has a grain composition of stone detritus (quartz, feldspar, detritic mica/clays) and a binder that may be clayey, quartzitic, or carbonatic (or mixtures thereof) [51, 55]. The mineral composition of limestone is mostly calcium carbonate, often derived fi om precipitated calcium carbonate and fossil shell remnants fi-om marine organisms and a calcitic binder matrix [51, 56, 57]. 

In summary, due to a relatively large proportion of externally derived material in soil, the trace element concentrations in the soil of the Swiss Jura are only partially representative for limestone-dominated systems. Nevertheless, many soils of the Jura mountains are rich in Cd of natural origin. It was demonstrated that this Cd derives from calcite dissolution and not from weathering of the insoluble clayey fraction of the rock. Moreover, unexpectedly high amounts of radon are released in this region. 

This trend appears to be confirmed by the analysis of the samples reliably associated with the different lithologies (Table 1). Indeed, roes harvested on clayey terrains have the highest median value, while those shot on limestones and heterogeneous flysches have the lowest ones. High values, even though referring to only three samples, come from roe deer which lived on mafic magmatic rocks. 

Neither age nor sex seems to influence the median values, which are not much different from the entire sample value of 96 ng/ml. Conversely, animals living on different background lithologies once again show some differences in Pb concentration in the blood. Roes harvested on clayey terrains have the highest median value while those shot on limestones have the lowest one. 

Silica and alumina, in the form of clay, silt and sand are commonly found as heterogeneous impurities in features such as faults and bedding planes, and also occur as homogenous impurities. When limestones containing 5 to 10 % of clayey matter are calcined, they produce feebly hydraulic limes those containing 15 to 30 % produce highly hydraulic limes [3.12] (see also section 26.9.2). 

A reportedly "easily burned" raw feed from the northeastern United States is seen in thin section to be a physical mixture of two kinds of rocks (a two-component feed)—clayey microcrystalline limestone and a fine-grained, calcific, quartz-mica siltstone (and low-grade schist) containing various amounts of an ironbearing mineral ceramic waste, spent catalyst, and other constituents are added. The feed contains 16.5% retained on the 125-pm screen and the >45-pm acetic-acid insoluble residue is approximately 8.9% loosely packed belite nests are common (25% of the belite), 75% of the belite is solitary, and the clinker is coarsely crystalline. 

Raw feed from the southwestern U.S., said to be unusually easy to burn, contains a clayey microcrystalline limestone and shale. The feed has only 3.2% retained on the 125-pm screen, with 15.2% >45 pm, and has <1.0% acetic-acid insoluble residue >45 pm, the latter composed of ordinary quartz with minor amounts of glauconite (a complex alkali-caldum-iron-magne-sium aluminosilicate). Belite nests are scarce and relatively small isolated belite is abundant. The clinker is finely crystalline, easily ground, and produces a high strength mortar (typically greater than 49 MPa). 

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