Early Finds and Field Reconnaissance
Professor Juan Armenta Camacho

Juan Armenta Camacho (left)

"[The Valsequillo Prehistoric Zone]...has suffered from severe erosion which has uncovered very old terrain in which outcrops of the calcareous marine basement rock (Cretaceous) stand out, and upon which rests a calcareous conglomerate, tuff layers, and alluvial and lacustrine sediments of undetermined age, and higher [in the section] consolidated stratified tuff layers called "xalnene", which underlie a thick sedimentary section of lacustrine deposits called "Tetela Formation", which has lenses of [Valsequillo] gravel[s] and is rich in the remains of Quarternary mammals..."

Traces of Human Workmanship on Extinct Animal Bone from Valsequillo, Puebla, Mexico

Presentation by Professor Juan Armento Camacho
at the 35th International Congress of the Americanists at Puebla in 1973