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  • Author or Editor: G. García-Rosales x
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Abstract  

The purpose of this research is the dating of some mammoth bones from the Valley of Mexico, with the uranium-series method, which can determine the activity of the isotopic relationships 234U/238U and 230 Th/234U. Since not all samples could be dated by this method, it was necessary to apply other techniques as well. First of all, the total concentration of uranium was determined in mammoth bones by U. V. spectrometry, then a study of the conservation state of mammoth bone was carried out by scanning electron microscopy and X-ray diffraction. In this way the limiting factors at the application of this method for dating mammoth bones can be determined.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: G. García-Rosales, E. Ordoñez-Regil, J. Ramírez Torres, J. López Monroy, M. Machain-Castillo, and L. Longoria-Gándara

Abstract  

This study deals with the characterization of a marine sediments profile from the Gulf of Tehuantepec, Mexico. Ten sediment samples obtained from a core of 18.3 m of length were analysed. Although there have been numerous marine sediments studies carried out in Mexico, more are needed to better understand the sea floor formation. Crystallographic, morphologic, physical, chemical and gamma ray activity analysis were carried out on the samples. The analysis results showed a decrease in organic matter content as a function of sea depth; this value is related to the specific surface area. Some hazardous materials as Cr, Mn, Ni, Sr and Hg were also identified by PIXE in some samples, probably due to anthropogenic activity. The presence of uranium a naturally occurring element was found in all the samples, suggesting a migration through all materials of strata, radioactive elements such as 226Ra, 235U, 212Pb, 214Pb, 228Ac, 208Ti, 214Bi, 228Ac and 40K were detected.

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