“…From north to south these sources are: Yarac Paccha, Callejones, Mullumica, El Tablón, Potrerillos, Rodeo Corrales, and YanaurcoeQuiscatola Bellot-Gurlet et al, 2008;Bigazzi et al, 1992;Burger et al, 1994;Dorighel, 2000;Salazar, 1992). Beyond the Sierra de Guamaní, in the southern Ecuadorian highlands near Saraguro, Ogburn et al (2009) have recently identified the obsidian source of Carboncillo, but it is unclear if it was used during the pre-Columbian era because no artifacts have been matched to this obsidian type. Several of the Northern Andean sources, such as Callejones, Mullumica and YanaurcoeQuiscatola, are well sampled and have been characterized through a number of geochemical analyses, including XRF, NAA Burger et al, 1994), Particle Induced X-ray Emission or PIXE (Bellot-Gurlet et al, 2008), and Inductively Coupled Plasma using an Atomic Emission Spectrometer (ICP-AES) or a Mass Spectrometer (ICP-MS) (Bellot-Gurlet et al, 2008).…”