Sourcing archaeological bitumen in the Olmec region

The emergence of Early–Middle Formative exchange patterns in Mesoamerica: A view from Altica in the Teotihuacan Valley

“…Her sample was small (n = 30) and taken exclusively from San Lorenzo, so it would be worth making thin sections of a larger sample from a broader region. Wendt and Lu's (2006) identification of bitumen seepages near San Lorenzo potentially supports this region as the source. Based on the minor frequency of metamorphic and volcanic inclusions in the Altica imported sample, we would expect the production location to be closer to the Sierra Madre Oriental because these rocks would increasingly drop out of the stream current as sediment with distance from the mountains.…”

How the Olmec used bitumen in ancient Mesoamerica

“…El Bajío's inhabitants might have participated in direct collecting at a nearby source. Preliminary results from Wendt and Lu's (2006) chemical sourcing analysis did not identify a source for the Bajío material, but Wendt was unable to gain access to (and sample) two seeps reported close to the site. An alternative to the scenario presented above is: the presence of bitumen slabs may indicate that bitumen (in the form of such slabs) was traded into the site.…”

“…In a late 19th century report on the feasibility of a ship canal through the Isthmus of Tehuantepec, Robert Shufeldt (1872, p. 67) lists 16 natural seeps, some of which may have been utilized by the Olmec (a list of these also appears in Coe and Diehl (1980a, p. 17)). Seven of these seeps along with five others were recently relocated and sampled (Wendt and Lu, 2006).…”

Chemical analyses of the earliest pigment residues from the uttermost part of the planet (Beagle Channel region, Tierra del Fuego, Southern South America)

“…These n-alkanes have also been detected in sample Imi 20 and in three of the nine natural pigment samples but they were not found in the archaeological sediment samples. This fact could be attributed to a biogeological origin in the inorganic components of the pigment residues and it rules out the use of a bitumen as binder because no steroid hydrocarbons (steranes, sterenes) or terpanes were detected (Wendt and Lu, 2006).…”