The Chivay obsidian source (15.6423° S, 71.5355° W, 4972 masl) is the

geological Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth s ...

origin of a chemically distinct type of

obsidian Obsidian ( ) is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Produced from felsic lava, obsidian is rich in the lighter element ...

that is found throughout the south-central

Andean The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long and wide (widest between 18°S ...

highlands including southern

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

and western

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

. Obsidian of this type is also known as the Cotallalli type or the Titicaca Basin type. Studies have shown that up to 90% of artifacts from the

Lake Titicaca Lake Titicaca (; ; ) is a large freshwater lake in the Andes mountains on the border of Bolivia and Peru. It is often called the highest navigable lake in the world. Titicaca is the largest lake in South America, both in terms of the volume of ...

Basin were made using obsidian from this source. These chemical characterization studies were performed using

X-ray fluorescence X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...

(XRF) and

Neutron Activation Analysis Neutron activation analysis (NAA) is a nuclear reaction, nuclear process used for determining the concentrations of chemical element, elements in many materials. NAA allows discrete Sampling (statistics), sampling of elements as it disregards the ...

(NAA) techniques. Obsidian from the Chivay source is found in large and homogeneous

nodule Nodule may refer to: * Nodule (geology), a small rock or mineral cluster * Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, ...

s in a high altitude

volcanic crater A volcanic crater is an approximately circular depression in the ground caused by volcanic activity. It is typically a bowl-shaped feature containing one or more vents. During volcanic eruptions, molten magma and volcanic gases rise from an ...

approximately to the east of the town of Chivay in the Colca Valley (Caylloma, Arequipa, Peru).

Consumption sites

Obsidian from the Chivay source has been chemically identified among artifacts from over fifty sites in the south-central Andes. Chivay obsidian was the predominant type found at the Archaic and Formative period site of Jiskairumoko on the western side of Lake Titicaca in the Ilave Valley of Puno, Peru.

References

* * * * * * * * Quarries in South America Stone (material) Archaeology of Bolivia Geology of Bolivia Archaeology of Chile Geology of Chile Archaeology of Peru Geology of Peru Obsidian {{Peru-archaeology-stub