Two thousand two hundred years ago, an ancient people living in present day-Colima carved an intricate map on a massive piece of volcanic rock. It remained forgotten for millennia until archeologists from the Instituto Nacional de Antropología e Historia (INAH) stumbled across it and revealed it for the world to see.
According to reports, the ancient map carved on the surface of the rock dates back to around 200 BC. It represents a regional map displaying ancient settlements that exists in present-day Colima. These ancient settlements are believed to have been represented by a series of circles (carved indentions), connected by a series of lines.
The map was carved on the surface of a basalt volcanic rock that likely originated from the Colima volcano, around 14 kilometers away from where it was found.
The rock measures just over 1,7 meters in height and sits oriented towards the volcano to the northeast.
“The highest part of the stone, 1.70 meters high, with an irregular width of between 2.12 and 2.77 meters and a thickness of between 60 centimeters and 1.70, has an axis of approximately 20 degrees to the northeast. It is oriented to the Volcan del Fuego,” reveal INAH researchers in their report.
As explained by INAH archaeologists Julio Ignacio Martínez de la Rosa, researchers were able to identify the contents fo the map after studying similar patterns and symbols in petroglyphs scattered in the area. The carved indentions on the surface of the stone are thought to represent settlements and cities, and a series of different lines and geometric features are believed to be markings illustrating orthographic and hydrological features of the area.
The stone map was studied and analyzed by archeologists Rafael Platas Ruiz. According to the researchers, in addition to the map displaying ancient settlements of the region, certain features of the rock also seem to correspond to parts of the southern slope of the Colima volcano, such as rivers and valleys.
In other words, the ancient stone map depicts what Colima’s landscape looked like between 2,000 and 2,200 years ago.
Explaining the discovery and the meaning for the stone map, Platas Ruiz emphasized that “these ‘map stones’ served to understand and facilitate the administration of the land. Furthermore, they were a way of preserving knowledge from one period to another, at a time when writing did not exist in the territory that is present-day Colima.”
In the report of the archaeological investigation, the researchers explain that the volcanic rock features at least three engraving techniques “polishing, pecking and wear” are appreciated.
Those techniques were used to represent the orographic and geographical landscape of the southern slope of the volcano, crossed by ravines, runoffs, and rivers that descend from the geological promontory.
Although the rock itself was not dated, researchers were able to compare its contents and symbols to other similar petroglyphs and geoglyphs in the area, which allowed them to draw a comparison between symbols, petroglyphs and ancient art from the Late Preclassic and Early Classic periods between 200 BC and AD 200, to the contents drawn on the stone.