Investigations by archaeologist Gonzalo Correal Urrego in 1984 have revealed the existence of a preceramic site with two layers. The oldest layer has been dated at 3410 years BP and the younger layer at 3135 BP.[4]
Correal Urrego has discovered preceramic tools and wooden beams in horizontal position, possibly used to against the lake overflowing. Different stone tools found are scrapers and chips with sharp edges. Other tools were handles, and white-tailed deer bone tools for perforation, scraping and cutting. Evidence of fireplaces and burial grounds has been uncovered. One of the burial sites contained a full skeleton surrounded by five skulls. Remains of fauna collected by the hunter-gatherers were mammals, birds and snails. The presence of basalt, not formed on the Altiplano, indicated movement from the Magdalena Valley.[4]
When the climatic conditions became drier and layers of volcanic ash were deposited around the lake in the first millennium BCE, the inhabitants of the region started to develop agriculture around the lake.[5]
Later excavations have provided ceramic with a typical red colour, rich in SiO2.[6]
The lake is a residual part of Lake Humboldt, but since 1973 functions as an artificial lake after the construction of drainage channels. The lake is fed from the Bojacá River from the northeast and from the San José channel, fed by the Bogotá River in the southwest. Between 1969 and 2013 the surface area of the lake has been reduced with 175 hectares (430 acres).[2]
Recent mining activities close to the lake endanger the environment of Lake Herrera, formalised a water reserve on July 23, 2006.[3][7]
Biodiversity
Flora and fauna around the lake is endangered and migrating birds use Lake Herrera.[1] Several species have been found and described in and around the lake:
Rodríguez, José Vicente (2005), "De la sabana a la selva - Un yacimiento formativo ritual en el entorno de la antigua laguna de La Herrera, Madrid, Cundinamarca - From the savanna to the jungle - a ritual formative site in the surroundings of the ancient Lake Herrera, Madrid", Maguaré (in Spanish), 19, Universidad Nacional de Colombia: 103–131
Further reading
Broadbent, Sylvia M. (1971), "Reconocimientos arqueológicos de la Laguna Herrera", Revista Colombiana de Arqueología, XV (in Spanish), 1: 171–214