Tracking rock sources of 3800-year-old burial goods using X-ray diffraction, electron microprobe analyses and X-ray mapping: a case study from Córdoba, Argentina

COLOMBO, FERNANDO; SARIO, GISELA; GORDILLO, SANDRA; FABRA, MARIANA

Rendiconti Lincei. Scienze Fisiche e Naturali

Springer

Año: 2020 p. 495 - 503

2037-4631

An axe head and a round bead were found at the burial site of an adult male (dated at 3770 ± 90 14C years BP) at Amboy,Córdoba (central Argentina). These artifacts were studied using electron microprobe, scanning electron microscopy andX-ray diffraction, for a complete characterization of the materials and to infer the source. The axe head is carved from veryfine-grained tonalite (composed dominantly of zoned plagioclase, quartz, potassic feldspar, chlorite, magnesiohornblende,titanite and magnetite) with microporphyritic texture. The bead is mainly composed of muscovite, an amorphous Cu?Alhydrated silicate (similar to chrysocolla) and malachite. Based on the coincidence between textures, mineralogy and chemicalcompositions, the most likely source of the axe is dykes of metaluminous tonalite scattered in the Sierras Chicas Range.The provenance of the bead could not be ascertained, but it is probable that it was carved from material collected from a verylocalized outcrop. These artifacts associated with a funerary context represent one of the oldest evidences of such materialsfor hunter?gatherer groups in central Argentina.