The densities and seismic velocities of rocks are relatively weak functions of temperature, pressure and composition unless these are accompanied by a drastic change in mineralogy. The physical properties of a rock depend on the proportions and compositions of the various phases or minerals-the mineralogy. These, in turn, depend on temperature, pressure and composition. In general, one cannot a...

Depiction of mineral solubilities on isobaric isothermal bulk composition pH diagrams facilitates considerably the conelation of the consequences of irreversible reactions with the solubilities of incongruent reaction products. The reaction-progress variable (f) is related to the bulk composition variable (r1", which has units of moles (kg HzO)-r) by the stoichiometries of the irreversible reac...

Investigation of modern and fossil teeth from northern and central Kenya, using the ion microprobe, electron microprobe, and transmission electron microscope, confirms that fossil tooth chemistry is controlled not only by the diagenetic precipitation of secondary minerals but also by the chemical alteration of the biogenic apatite. Increases in the concentrations of Fe, Mn, Si, Al, Ba, and poss...

The Biwabik Iron Formation is a approximately 1.9 billion year-old sequence of iron-rich sedimentary rocks that was metamorphosed at its eastern-most extent by approximately 1.1 billion year-old intrusions of the Duluth Complex. The metamorphic recrystallization of iron-formation locally produced iron-rich amphiboles and other fibrous iron-silicate minerals. The presence of these minerals in ir...

Laser-induced breakdown spectroscopy (LIBS) provides an alternative chemical analytical technique that obviates the issues of sample preparation and sample destruction common to most laboratory-based analytical methods. This contribution explores the capability of LIBS analysis to identify carbonate and silicate minerals rapidly and accurately. Fifty-two mineral samples (18 carbonates, 9 pyroxe...

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or mangan...

the cheshin meta-calcareous rocks (permo triassic) in southeast hamedan outcrop in association with a variety of pelitic schists and hornfels rocks. the intrusion of the alvand batholith (jurassic age) into pelitic and calcareous host rocks has produced metamorphic rocks in the hamedan area (cheshin village). on the basis of the dominance of calcite/dolomite, silicate and ore minerals, the calc...

Mining in its broadest sense is the process of obtaining useful minerals from the earth’s crust. A mineral is generally defined as any natural accruing substance of definite chemical composition and consistent physical properties. An ore is a mineral or combination of minerals from which a useful substance, such gold, can be extracted and marketed at a price that will recover the costs of minin...

The cactus prickly pears rich in micronutrients, has recently generated a great deal of consumer interest, therefore, this paper was designed to study its physical and chemical compositions such as: moisture, sugar content, total fibres, protein, ash, pH, acidity, minerals contents and total phenolics contents of nine prickly pear juices. Polyphenols are antioxidants who contribute to the nutri...

Vertebrate fossils and continental sediments provide a rich record of variations in the isotopic composition of surface environments. To interpret these records, a greater understanding of isotopic sources, as well as fractionations associated with animal physiology, soil geochemistry, and diagenesis, has been essential. Tooth enamel and fish otoliths yield subannual records of surface environm...