Calcium terrestrial samples

Two bioassays are employed to evaluate the effect of samples on terrestrial life forms. For gas samples, the plant stress ethylene test is presently recommended. This test is based on the well-known plant response to environmental stress release of elevated levels of ethylene (under normal conditions plants produce low levels of ethylene). The test is designed to expose plants to various levels of gaseous effluents under controlled conditions. The ethylene released during a set time period is then measured by gas chromatography to determine toxicity of the effluent. For liquid and solid samples, a soil microcosm test is employed. The sample is introduced on the surface of a 5 cm diameter by 5 cm deep plug of soil obtained from a representative ecosystem. Evolution of carbon dioxide, transport of calcium, and dissolved oxygen content of the leachate are the primary quantifying parameters. 

Oxygen 3-isotope plot showing excesses of 160 in minerals from calcium-aluminum inclusions (CAIs). All samples from Earth rocks plot along the terrestrial fractionation line. Mass-dependent fractionation processes cannot move a composition off of this line, so the excesses of 160 were clearly isotopic anomalies. After Clayton et al. (1977). 

Merrillite, an anhydrous calcium phosphate mineral often coexisting with apatite in lunar and meteorite samples, has been used for a number of fission track dating studies of extraterrestrial materials. Following a paper by Fuchs (1962) this mineral was most commonly identified in meteorites as whitlockite, but Dowty (1977) has shown that it exhibits significant differences to terrestrial whitlockite, (Ca,Mg)3(P04)2, and should be distinguished from it. As a result, earlier publications use whitlockite while later ones apply the name merrillite , for the same mineral. Merrillite is now the appropriate species name for the high-temperature phosphate mineral found predominantly in... 

Inorganic Materials. During petrification, the types of inorganic substances that replace organic substances will depend on the burial environment. Phosphates and silicates have been found in petrified wood from the marine environment, and calcium minerals in samples from terrestrial and cave environments. High iron contents are always associated with shipwrecks. All these impregnates will influence the analytical methods and conservation treatments. 

A comprehensive review of the chemical composition of the lunar surface, as ascertained by analysis of samples obtained on the Surveyor and subsequent Apollo and Luna missions, has been collated by Turkevich. The lunar surface is made up of silicate rocks, the principal minerals being calcium-rich feldspars and pyroxenes. In many respects the chemical composition of the maria analysed are similar to those of the terrestrial basalts. The terra regions analysed are distinctly different from the maria in having considerably smaller amounts of iron and titanium and larger amounts of calcium and aluminium. Apollo missions have shown that the lunar mare material is very dry and was produced under relatively reducing conditions. 

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