Argillaceous limestone

Cementstone is an impure (usually argillaceous) limestone, possessing the ideal balance of siUca, alumina, and calcium carbonate for Portiand cement (qv) manufacture. When calcined it produces a hydrauHc cementing material. 

Cement. Portland cement, a mixture of calcium siUcate and calcium aluminate minerals, is produduced by the calcination of argillaceous limestone or mixtures of limestone and clay (see Cement). Although other clays can be used, ka olin is preferred because of its alumina and siUca content and low level of impurities. It is especially desirable in the manufacture of white cement and other types requiring careful control of chemical composition. Air-floated ka olin, because of its low cost, is usually used. 

Argentite, natural occurrence of, 22 668 Argentium Sterling, 12 562 Argentothiosulfate complexes, 19 215 Argillaceous limestone, 15 26 Argillic alteration zones, gallium in,... 

Weaver (1959) noted that the chlorite, which is a common constituent of the Ordovician K-bentonite beds of the eastern United States, has a dioctahedral 2 1 layer and a trioctahedral hydroxide sheet. A partial chemical analysis indicated the chlorite contained less than 2% Fe203. Both layers were probably formed in place from the alteration of volcanic ash in a marine environment. Only one other chlorite of this type had been detected in X-ray patterns of approximately 75,000 samples of sedimentary rocks. The other sample was from a Paleozoic argillaceous limestone at a depth of 24,400 ft. in Oklahoma. Chlorites of this type might well go undetected when chlorite is only a minor component. 

The Middle Devonian Marcellus Formation consists of black bituminous shale and minor argillaceous limestone lying conformably on the Dundee Formation limestones. Its depositional setting resembles that of the Whitby Formation and the Marcellus... 

The basal part of the Ocala Limestone consists of about 29 ft of white, coarsely crystalline, fossiliferous limestone. This sequence is overlain by about 43 ft of dense argillaceous, fossiliferous limestone interbedded with thin clay laminae and about 5 to 8 ft of soft, chalky limestone. The void spaces within the argillaceous limestone have been partially filled with clay, and the unit has low permeability. 

Natural hydraulic limes, as defined in [16.60] (see section 26.9), are produced from siliceous or argillaceous limestones containing more or less silica, alumina and iron [16.61]. Typical levels in the limestone are [16.6] ... 

In 1796, James Parker, of London, patented a process for calcining argillaceous limestones (or cementstone) to produce a type of cement, which was also called Roman Cement. This development was followed in 1824 by Joseph Aspdin, of Leeds, who lightly calcined a finely divided mixture of limestone and clay and ground the product to make hydraulic cement. The product was called Portland cement. 

Argillaceous limestone contains significant amounts of clay or shale (i.e. of silica and alumina). 

Roman cement was the predecessor of today s Portland cement. It was produced by calcining nodules of argillaceous limestone to temperatures below sintering that is, to about 900-1000°C. The binder obtained this way has been called inappropriately Roman cement, even though it in no way resembles the binder in mortars itsed by the... 

Cause analyses of failure modes and protection measures of dissolution argillaceous limestone slopes in the Three Gorges Area... 

Figure 1. Research area of dissolution argillaceous limestone in Three Gorges region. 

Dissolution argillaceous limestone bank slopes widely distribute in Three Gorges reservoir area. It is easy to find that after dissolution argillaceous limestone will develop dissolution cracks and small karst caves in a wide range. Meanwhile, the rock formation is getting thin and rock is fractured. In Figure 2, there is an otherness dissolution strip... 

Characteristics of the lithologic combination group of dissolution argillaceous limestone slope... 

Observed from Slope profiles, marl and dissolution argillaceous limestone develope alternately with interlayers of limestone or calcareous mudstone in strips, but often in a gradual transition state without clear boundary. 

In layer structure, it usually occurs medium-thick layer dissolution argillaceous limestone thin interlayer and medium-thick layer containing thin layer dissolution argillaceous limestone alternately, partly mega-thick layer argillaceous. 

Dissolved pores and dissolved gaps are developed in dissolution argillaceous limestone, partly seeing calcium argillaceous cemented karst breccia. 

WEAKENING ROCKMASS STRENGTH OF DISSOLUTION ARGILLACEOUS LIMESTONE UNDER WEATHERING AND HOMOGENEOUS DISSOLUTION DEFORMATION AND DAMAGE... 

Table 2. Rock mechanics parameters of dissolution argillaceous limestone slopes.

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