Geoquímica Diamante XRF

Name: Geoquímica Diamante XRF
Keywords: GEOQUÍMICA

Datos de investigación

Geoquímica Diamante XRF

Autores: Salgán, María Laura Icon

; Franchetti, Fernando Ricardo

Colaboradores: Otaola, Clara Icon

; Giardina, Miguel Angel Icon

Publicador: Consejo Nacional de Investigaciones Científicas y Técnicas

Fecha de depósito: 10/01/2023

Fecha de creación: 01/01/2021-20/02/2021

Clasificación temática:

Arqueología

Resumen

Conjunto de datos geoquímicos de artefactos de obsidiana procedentes de sitios de la cuenca alta y media del río Diamante, San Rafael, Mendoza.

Métodos

We measured the geochemical characteristics of these obsidian artifacts with a portable Olympus Delta DP-6000 GeoChem x-ray florescence spectrometer (pXRF). This pXRF unit emitted two X-ray beams (10 keV and 40 keV) configured to operate for 60 seconds, each using the default geochemical calibration setting provided by INNOV-X (Pilloud et al. 2017). Using a laptop connected to the pXRF unit, we collected trace element data for each artifact. The data were exported to an excel file after each session. We also analyzed geological samples from known obsidian sources with the pXRF unit to facilitate the determination artifact provenance. The geochemical signatures of the known sources had previously been characterized by the neutron activation technique in the archaeometry laboratory at the University of Missouri Research Reactor (MURR). We only included variables for rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), and niobium (Nb). These elements (mid Z) have an atomic number between 19 and 41. Mid-Z elements can be detected with little background effect, making their error rates predictable (Shackley 2013). The assignation of samples to sources is possible when sources are chemically distinct. We also used a statistical approach that improves the precision of source assignation when working with relatively small samples like ours. This method generates graphs of paired elements, for example: Sr / Rb, Rb / Zr, Sr / Zr, Y / Zr, Nb / Zr, instead of using just raw element concentrations. We used this last method for sources that partially overlap in trace element concentrations: Las Cargas, Arroyo Paramillos, Laguna del Diamante and Coche Quemado (Figure 2B) (Cortegoso et al. 2012, 2020; Salgán et al. 2015, 2020). We loaded the geochemical data into the GAUSS software developed by MURR. The GAUSS program enables analysts to generate multiple bivariate scatterplots of various combinations of trace elements and to quickly calculate confidence ellipses. In many cases, especially in regions where only a few obsidian sources are found, this approach may be sufficient to correctly assign artifacts to geological sources (Glascock et al. 1998).

Palabras clave: GEOQUÍMICA, FLUORESCENCIA DE RAYOS X, OBSIDIANA, SUR DE MENDOZA

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Consultar

Identificador del recurso

URI: http://hdl.handle.net/11336/184184

Colecciones

Datos de Investigación (IDEVEA)
Datos de Investigación de INSTITUTO DE EVOLUCION, ECOLOGIA HISTORICA Y AMBIENTE

Citación

Salgán, María Laura; Franchetti, Fernando Ricardo; (2023): Geoquímica Diamante XRF. Consejo Nacional de Investigaciones Científicas y Técnicas. (dataset). http://hdl.handle.net/11336/184184

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