Obsidian-bearing lava flows and pre-Columbian artifacts from the Ecuadorian Andes: First new multidisciplinary data

Provisioning of the Inka army in wartime: obsidian procurement in Pambamarca, Ecuador

“…The appearance of Yanaurco-Quiscatola material in Inka contexts is notable given that exploitation of that source seems to have ceased around AD 1000 (Bigazzi et al, 1992). The impetus for abandonment is unknown, but it is intriguing that the source was once again exploited in Inka times.…”

“…The fifth artifact from La Chimba was noted as a ''deviant'' type of material that is chemically distinct from the Sierra de Guamaní obsidians ; here we refer to it as the La Chimba type. Two other sources of chemically distinct archaeological obsidian are indicated by the analyses of Bellot-Gurlet et al (1999) and Bigazzi et al (1992). Bellot-Gurlet et al (1999) posit the existence of additional sources, based on fission-track analysis of a number of artifacts, though it remains to be shown whether those distinctions are meaningful in terms of defining obsidian quarries.…”

“…Obsidian occurs in a number of locales within Ecuador (BellotGurlet et al, 2008;Bigazzi et al, 1992), although only a few of those deposits contain material suitable for manufacturing stone tools. To date, four of the known deposits have been identified as sources of archaeological obsidian.…”

“…The Callejones source is located about 6 km to the east of the center of Mullumica; fewer data are available from Callejones source samples, but it is apparent that the two sources are closely related chemically. Located about 10 km west-southwest of Mullumica, the Yanaurco-Quiscatola source encompasses erosional remnants of obsidian flows on two separate mountains, Yanaurco Chico and Quiscatola (Bigazzi et al, 1992). Those flows were likely produced by the same volcanic event, and because the obsidians from the two loci are chemically indistinguishable, researchers have treated them as a single source.…”

Evolution of the late Pleistocene Mojanda–Fuya Fuya volcanic complex (Ecuador), by progressive adakitic involvement in mantle magma sources

“…Based on K/Ar data (Barberi et al 1988), the construction of Mojanda is thought to have started about 0.6 Ma ago. Robin et al (1997) showed that its activity ended just before the eruption of the regional "Pifo ash-fall layer", which originated in the Chacana caldera 0.18-0.20 Ma (Bigazzi et al 1992) or~0.165 Ma ago (Hall and Mothes 1997). Fuya Fuya's activity started before the end of the first main construction phase in Mojanda, i.e.…”