Tiahuanaco is a small village south-east of Lake Titicaca, is a world-famous archeological site with 1,400-year-old monuments and ceremonial buildings. The precision and detail of these sculptures called the attention of scientists who doubted that they could have been created with the simple tool technology known at the time. 

A new pre-print, a scientific study that is completed but have not yet been peer-reviewed by other scientists, claims to solve the mystery: the ‘H shaped’ blocks of one of the most iconic temples ‘Pumapunku’ is not made of rock (as it was always thought), they’re made of sand!

Since archaeologists found the ruins of Tiahuanaco, they tried to find their source of materials, as almost all of the ancient city was made of rock blocks. In 1892 researchers discovered that these rocks (called andesite) were collected from an outcrop located at the foot of a volcano named “Cerro Khapia.” 

A geochemical analysis revealed that the composition of the H shaped blocks from Pumapunku coincided with the andesitic sand but that also included organo-mineral binders, bat droppings, and other ingredients used to produce andesite geopolymer blocks. 

The discovery of Tiahuanaco’s material supply route revealed the great ingenuity of ancient construction workers who created incredibly resistant blocks by using what they could find around them in ways archeologists had not anticipated.