PAMA Archaeology Project
Puno, Peru 2022
The Proyecto Arqueológico Medio Ambiental (PAMA) 2022 was directed by Dr. Sarah Kennedy, Dr. Sarah Kelloway, and Lic. Karen Durand Cáceres, in collaboration and partnership with the Collacachi and Malcomayo Aymara Indigenous communities, with the goal of asessing the risk abandoned colonial mines and refineries pose to modern Andean communities in the Puno Bay of southern Peru.
The summer 2022 field season documented four colonial mining archaeological sites (1600-1800 AD) and one Late Intermediate Period hillfort site (1000- 1450 AD) using GPS mapping, pXRF soil composition data, and water and vegetation sampling. These methods were used to determine the impact of historic metallurgy and metal working on modern agricultural environments by identifying and mapping heavy metal remnants within the soil, waterways, and vegetation present at these significant archaeological sites. A second goal of the project was to build relationships and channels of communication with local communities, health organizations, and NGOs, thus enabling current and future archaeologists to share information from their research about heavy metal poisoning and accessible mitigation options for those potentially affected.
Chorrillos
Chorrillos Itapalluni was a colonial silver refinery and work camp located on the Itapalluni River, close to the Laicacota and Cancharani silver mines near Puno. While it is sometimes erroneously known as San Luis de Alba (the abandoned colonial mining town), it was actually a large industrial complex that was used for processing minerals.
Local farmers and herders still live near the site, although living inside the site is now prohibited as the complex is a protected archaeologyical site under the Peruvian Ministry of Culture.
Santo Cristo
Santo Cristo was a colonial silver refinery and work camp located on the San Miguel River. In the past, the river was known as the Uncalliri (Aymara for "with ducks"). Historical documents indicate Joseph Duran built a refinery here in 1691 and named it Santo Christo de Vilque.
The site was not fully abandoned and Indigenous farmers and herders continued to live there in the 1800 and 1900s, up until 2020.
San Miguel
San Miguel was a colonial silver refinery and work camp built on the San Miguel River.
It was also not fully abandoned and Indigenous farmers and herders continue to live there. Our project worked in conjunction with the local owners of the site to do mapping and testing and they gave us full permission.
Trapiche Itapalluni
Trapiche Itapalluni is another colonial silver refinery and work camp in the region. It is located on the Itapalluni River, and was used in the 1600 and 1700s. No one has been actively living there since the late 1800s.
This refinery has been extensively studied (mapped, surveyed, and excavated). This was the first site we tested our pXRF heavy metal survey at in 2018. The 2022 field season consisted primarily of taking vegetation and water samples from the site, since we had already tested the soils.
Machu Llaqta
Machu Llaqta, also known as Ayawiri or Hatunpata, was a pre-colonial hilltop city built by the Colla people during the Late Intermediate Period (1000 - 1400AD). We know from pervious archaeological excavations that the Colla did conduct metal smithing here, although not to the extent we see in the later period silver refineries. We mapped and tested this site to provide a comparison with the colonial refineries.
Our Field Methods
pXRF Spectroscopy
The portable X-ray Fluorescence Spectrometer (pXRF) is a hand-held device used to conduct soil analyses in the field. The pXRF, borrowed from the Universidad de Ingeniería y Tecnología (UTEC), Lima, is calibrated to measure levels of various heavy metals including mercury, lead, and arsenic used in the refining process. Each sample area was prepped for analysis by clearing the topsoil of interference such as vegetation and small pebbles, helping us maintain consistency across sites.
Team members use the pXRF instrument to measure the amount of heavy metals in each site's soils.
Trimble GPS Mapping
A central objective of the project required the use of Global Positioning System (GPS) mapping to locate and record the positions of our pXRF sampled areas, allowing us to analyze and compare spatial patterns within and across sites. A Trimble Geo 7X unit from the St. Olaf/Carleton College GIS laboratory provided us with GPS data with an accuracy of 30 cm or less which could be differentially corrected each evening to further increase accuracy. By importing the data into GIS mapping software such as ArcMap and ArcGIS Online, we could visualize the locations of our pXRF, vegetation, and water samples, as well as any significant site features including grinding stones, canals, reservoirs, and buildings.
Team members use the Trimble GPS unit and antenna to record the location of our testing points.
Vegetation Sampling
With guidance from our local Indigneous collaborators—Javier Chalcha Saraza, Ofelia Choque Arocutipa, and Roger Carazas Losa—we were able to identify and collect an exhaustive assemblage of native plant species growing within the boundaries of our contaminated archaeological sites and accessible to grazing livestock. Roots, foliage, and soil samples near the roots were collected from each plant to be analyzed later for heavy metals. Should our results reveal that the heavy metals present in the soils are also present in the vegetation, there is the potential for negative consequences on the health of local populations.
Team members identify and collect plant samples.
Water Sampling
Water sampling was a critical component of determining the lasting environmental impact of colonial silver refineries on local populations, as the Itapalluni and San Miguel rivers flow near each site. Furthermore, these rivers are the primary water source used by the local Indigenous people living in this area. We collected water samples from each site at several points in the rivers, both near the bank and in the center, as well as upstream and downstream from the site. These samples, along with sediment samples from the same rivers, will be analyzed for heavy metals.
Team members take water samples from rivers near the sites.
Indigenous Participatory Action Research
We conducted interviews with Puno-based government ministries, non-government organizations (NGOs), and landowners near the survey sites. Interviews focused on how information about mining, heavy metals, and water safety is communicated to and understood by local communities. Interviews were conducted primarily in Spanish, with Aymara translation from Roger Carazas Losa, Javier Chalcha Saraza, and Ofelia Choque Arocutipa. We learned that heavy metals findings presented with visuals, solutions, and support of recognized community leaders are the most useful to local communities and plan to distribute our results using these methods.
Team members conducting interviews and outreach, as well as archaeological research.
Acknolwedgments
Thank you to Carleton College and the Archaeological Institute of America's Julie Herzig Desnick Endowment Fund for sponsoring this project. We would like to thank Juan Carlos Rodríguez and the Universidad de Ingeniería y Tecnología in Lima for loaning us the pXRF, Bree Morgan, Tom Savage, and the University of Sydney for loaning us the EC and pH equipment, and Wei-Hsin Fu and the Carleton College GIS Lab for loaning us their Trimble GPS . Further thanks to the Peruvian Ministry of Culture for allowing us to work at their cultural heritage sites, as well as the local communities who gave us permission to survey their land. We are especially grateful to our Peruvian team members, Lic. Karen Durand Cáceres, Ofelia Choque Arocutipa, Roger Carazas Losa, and Javier Chalcha Saraza.
Some of the members of our PAMA 2022 team, outside our Puno field house.
