Limestone study

Early limestone studies utilized whole-rock samples, but later individual components, such as different generations of cements, have been analyzed (Hudson 1977 Dickson and Coleman 1980 Moldovanyi and Lohmann 1984 Given and Lohmann 1985 Dickson et al. 1990). These studies suggest that early cements ex-... 

De Witte, E., Huget, P., Van De Broeck, P. (1977). A comparative study of three consolidation methods on limestone. Studies in Conservation, 22(4), 190-196. 

W1 is Bond work index based on 100 percent passing a 200-mesh sieve, is the sohds feed rate in kg/min, and S is weight percent solids in the feed. This represents experimental data for limestone, feldspar, sulfide ore, and quartz. The influence of Wl is believed to be due to its effect on amount of fines present in the mill. Parameters that did not affect are specific gravity of feed material, and feed size over the narrow range studied. 

Hillier, S.H. (1984). A Quantitative Study of Gap Recolonization in Two Contrasted Limestone Grasslands. PhD thesis. University of Sheffield. 

In general, chelating agents possess some unique chemical characteristics. The most significant attribute of these chemicals is the high solubility of the free acids in aqueous solutions. Linear core flood tests were used to study the formation of wormholes. Both hydroxyethylethylene diaminetriacetic acid and hydroxyethyliminodiacetic acid produced wormholes in limestone cores when tested at 150° F. However, the efficiency and capacities differ. Because these chemicals have high solubility in the acidic pH range, it was possible to test acidic (pH less than 3.5) formulations [644]. 

The name of compounds whose molecules contain three or more elements, usually including oxygen, ends in the suffix ate. Thus the chemical name for limestone, whose chemical formula is CaC03, is calcium carbonate. That of green vitriol, also known as copperas, whose formula is FeS04, is iron sulfate. The names and formulas of some chemical compounds related to archaeological studies are listed in Table 7. 

In Gubbio, Italy, a 1 cm layer of clay between extensive limestone formations marks the boundary between the Cretaceous and Tertiary Periods. This clay layer was known to have been deposited about 65 million years ago when many life forms became extinct, but the length of time associated with the deposition was not known. In an attempt to measure this time with normally deposited meteoritic material as a clock, extensive measurements of iridium abundances (and those of many other elements) were made on the Gubbio rocks. Neutron activation analysis was the principal tool used in these studies. About 50 elements were searched for in materials like the earth s crust, about 40 were detected and about 30 were measured with useful precision [26-28]2. 

The geology of the study area comprises mainly limestones, shales, alluvial deposits and basic extrusive and intrusive rocks. 

Fig. 2. Increase in titration alkalinity of groundwater from a thin limestone aquifer iin the central USA over the study period is accompanied by increasing groundwater CO2 and decreasing pH (not shown).

Picer et al. [49] described a method for measuring the radioactivity of labelled DDT contaminated sediments in relatively large volumes of water, using a liquid scintillation spectrometer. Various marine sediments, limestone and quartz in sea water were investigated. External standard ratios and counting efficiencies of the systems investigated were obtained, as was the relation of efficiency factor to external standard ratios for each system studied. 

The lower explosive limit and minimum explosive concentrations of flax, wool, cotton, jute, hemp and sisal fibres are of the same order of magnitude as those of highly explosive dusts [15], The explosibility of pyrites dusts with sulfur contents above 20% was evaluated experimentally. Dusts of 30% sulfur content gave explosion pressures of 3 bar at pressure rise rates of 16 bar/sec. Mixtures of 60% pyrites and 40% powdered limestone still showed significant pressure effects, and the proportion of limestone actually needed to suppress explosions was considerably above the values currently accepted by mining industries [16], Effects of mixtures of particle sizes in combustible dusts upon minimum ignition temperature (T ") and upon presence or absence of explosion were studied. Presence of 30% of fines in a coarse dust lowers Tf significantly [17], Experimental explosions of polyethylene,... 

In a special publication devoted to sulfide ore dust explosions, a dust explosion in a copper-zinc sulfide mine is discussed and related to causes and preventive measures [1]. Control measures [2] and prevention of secondary explosions are also discussed [3], and surveyed, including the need for further work [4], The results of experimental work on the use of limestone dust to suppress explosions in pyrites dusts are presented [5], For another special publication on ore dust explosion with numerous incidents and further studies on mechanism and control see [6], Explosibility declines in the order pyrrotite, pyrite, chalcopyrite, sphalerite, covellite, chalcocite, galena. Pyrite at 1000 g/m3 can give a peak pressure of 5.8 bar [7], Self heating of broken sulfide ore, to possible ignition, has been studied. Pyrrhotite seems primarily responsible [8],... 

Figure 8. A Mg vs. 5 Mg plot of limestone, dolostone, and marble samples (data from Galy et al. 2002) compared with a sample of foraminifera of various species (Chang et al. 2003) and seawater (Chang et al. 2003, this study). The broadly horizontal trend of the carbonates at elevated A Mg suggests a component of equilibrium fractionation relative to seawater. The P value derived by regression of these 5 Mg and 5 Mg data is within the range for equilibrium fractionation and statistically distinguishable from purely kinetic fractionation.

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