Astronomically-Forced Lake Expansion and Contraction.
Accurate trace-metal and strontium-isotope analyses of archaeological corn cobs require that metal contaminants be removed prior to chemical analysis. Archaeological cobs are often coated with construction debris, dust, or soil which contains mineral particles. In addition, most archaeological cobs are partially or completely burned and the burned parts incorporate mineral debris in their.
Strontium is a gray and soft, silvery metal with an atomic number of 38. It has four naturally occurring isotopes 88Sr, 87Sr, 86Sr, and 84Sr with abundances of 82.53%, 7.04%, 9.87%, and 0.54% respectively. Strontium is divalent in all compounds, which are, as hydroxide, fluoride and sulfate, completely soluble. Strontium is weaker complexing calcium, forming a few weak complexes with oxy.
The measured value in strontium isotopic analysis is the ratio of the natural abundancy of two of strontium’s’ isotopes; naturally occurring 86Sr and radiogenic 87Sr that is derived from the decay of rubidium-87 (Bentley 2006; Hodell et al. 2004; Price et al. 2002; Sealy et al. 1991). While this number is small (averaging approximately 0.71025 worldwide (C. Chenery et al. 2011)), it is a.
Whilst several programmes of strontium isotope analysis have included pig enamel samples, very few have produced samples of allocthonous origin and the validity of the technique for reconstructing movement of pigs remains in question. This study tests the validity of using strontium isotope ratios in porcine enamel for tracking the movement of pigs in two ways. Firstly, the susceptibility of.
Carbon and nitrogen isotope analysis of collagen is an established method for reconstructing diet in past human and animal populations. The nitrogen ratio provides an indication of the trophic level at which an individual is feeding, with diets heavy in animal or marine protein being more enriched in the heavier isotope (15N). The carbon ratio establishes the degree of marine input in feeding.
Analysis Sr Isotope Analytical Procedure. Sr isotopes are measured on a multi-collector thermal ionization mass spectrometer, which allows the simultaneous measurement of 84Sr, 85Rb, 86Sr, 87Sr, and 88Sr. Sr isolated from a sample is loaded in a nitric acid solution onto a tantalum filament along with a TaCl loading matrix with helps control the ionization of the Sr from the filament. This is.
