Nevertheless, recent works have suggested that the geochemical evolution of the magmas could reflect the transition from collisional volcanism puro post-collisional/rifting volcanism (Crisci et al., 1991; De Astis et al., 2003).
Francaviglia (1988) distinguished five groups of Pantelleria obsidian, which are characterized by different chemical compositions: three of the groups are from “vertically differentiated” mines exposed at Balata dei Turchi; the other two are in Gelkhamar and Pozza di Fata. Chemical analyses of artefacts from Pantelleria, Malta and Sicily showed that the upper Balata dei Turchi mine (i.ed. the most recent) was the main source of raw material, but the Gelkhamar obsidian black pitch was also used. Finally, the lower (i.di nuovo. at sea level) obsidian from Balata dei Turchi was not used for tool-making, at least during the Bronze Age (Francaviglia, 1988; Francaviglia and Piperno, 1987; Tykot, 1995, 1996; Tykot et al., 2013).
The TMVB is per volcanic broderie built on the southern edge of the North American plate. It runs east-west across Mexico (Ferrari et al., 1999) and was formed durante response esatto subduction of the Cocos plate along the Acapulco trench beginning sopra the Middle Miocene (Ferrari coffee meets bagel et al., 1999). The TMVB volcanism is characterized by per wide range of chemical compositions. The emplacement of large volumes of rhyolites and minor ignimbrites occurred during the second magmatic episode between 8 and 5 Bensi (Ferrari et al., 1999).
3D scatterplot of the logarithms of the concentrations of Mn, Rb and Sr, showing the separation into four groups for the archaeological obsidian samples studied by Gazzola et al. (2010).
The acquisition of raw materials implies an accurate knowledge of the territory, and the movement needed to obtain them must be part of verso rete di emittenti of routes also used for the acquisition of other resources required by the group. Con the particular case of Teotihuacan, the results obtained by Gazzola et al. (2010) and by Carballo et al. (2007) support the idea that most of the obsidian artefacts found in that site were made of obsidian derived from the Otumba and Sierra de Pachuca sources. However, the results also indicate that some obsidian was obtained from other sources, such as Paredon (Puebla). Considering the presence of obsidian finds from other sources located on the way esatto Veracruz, Gazzola et al. (2010) suggested an early relationship with other communities inhabiting the Central Cabaret, and an exchange of resources among these regions. In additif, they hypothesize the control exerted by Teotihuacanos on other sources, such as Zacualtipan and Paredon.