Digital Data Capture from the Ostra Collecting Site, Peru

Grantee: Emily Blackwood (Ph.D. candidate, UMaine)

Expedition Dates: July 12th – 27th, 2024

Field Team Members: Emily Blackwood (Ph.D. candidate, UMaine), Kelly Hoover (MS
student, UMaine), Dan Sandweiss (Professor, UMaine), Alice Kelley (Associate Research
Professor, UMaine), Alan Gontz (Professor, Clarkson University), Cecilia Mauricio (Professor,
Pontificia Universidad Católica del Perú)

Expedition Funding: Dan & Betty Churchill Exploration Fund

Background and Study Area:
For several weeks during the month of July, 2024, I traveled to Peru as part of an
interdisciplinary team of researchers with the goal of digitally capturing spaces and structures as
well as creating 3D models of cultural material from archaeological sites on the coast of Peru.
One of these sites, the Ostra Collecting Station (OCS), is the primary site being used in my
dissertation research, which entails reconstructing the site and its environment in virtual reality
(Figure 1).

This is a mid-Holocene site, radiocarbon dated to approximately 6,200-6,600 calibrated years
before present (BP) with an ancient shoreline still visible at its edge; in present day the Pacific
Ocean is located 5 km west. The abandonment of the site is probably due to retreat of the
shoreline and its associated resources. Dated to a time when the shoreline was right next to the
site, the OCS’s cultural material has revealed a unique story. A 9 x 8 meter granite stone
structure sits atop an ancient sea cliff and is surrounded by dense shell heaps. Two types of
diagnostic artifacts have been recovered: slingstones and incised planed / nonplaned pebbles
(Figure 2). The slingstones are fist sized, round or football shaped stones that were collected into
2 lines of ~ piles each with the southern line extending from the structure. The incised planed /
nonplaned pebbles were unique to this site’s sister site (Ostra Base Camp) located 5 km to its
south until 2018 when one incised planed pebble was recovered from OCS; 17 more were
recovered this field season, cementing the sites’ direct association to each other!

The species of bivalve shells that contribute to the heap matrix no longer inhabit this region of
the coast due to the cold temperatures of the Pacific Ocean at this latitude which lead Dan and
his colleagues (Rollins et al. 1986; Sandweiss et al. 1996, 2020) to believe that the environment
of the site and region during occupation was warmer than what is experienced in present day.

The second site visited was Los Morteros, a mid-Holocene site ~23 km north of OCS,
radiocarbon dated to approximately 5,500 calibrated years BP. This is another unique site due to
its age, size, hypothesized construction methods, purpose, and cultural materials. Currently
thought to be a mound built through the intentional capture of sand, its size and location atop an
ancient shoreline add to its story. Here, the shell heap bivalve species indicate cooler water
temperatures when compared with OCS. My primary purpose was to supplement Kelly Hoover’s
GPR data collection by creating a 3D model of the site (Figure 3).

Methods:
Technology and methods of capture and processing have advanced since my first visit to the
OCS site in 2018, and the data collected during this field season should allow me to build on and
enhance my simulated environment of the site. A GoPro was used to collect photos of several
specific areas of interest within the site that will be stitched together using photogrammetry
(Figure 4). This will allow the user exploring my virtual site to experience high resolution
models of the areas of interest within the site.

The Polycam app was also used due to its ability to use LiDAR or photogrammetry to create
high resolution 3D models of objects and spaces in the lab or in the field that can be incorporated
into the simulation as digital assets (Figure 5).

Acknowledgements:
First and foremost, I would like to thank and acknowledge the ancestors of the sites used in this
research for the opportunity to collect new data and add to our understanding of the context of
these spaces. A special shoutout to Kelly Hoover who was instrumental in collecting GoPro data
at OCS! A big thank you to our Peruvian collaborators, Cecelia Mauricio (Pontificia Universidad
Católica del Perú) and her team for their time, patience, gear borrowing, and knowledge sharing!
Thanks to my committee members, Dan Sandweiss (UMaine), Alice Kelley (UMaine), and Alan
Gontz (Clarkson University) for helping guide me along my academic journey. Finally, a HUGE
thank you to Dan and Betty Churchill for providing the funding for this research!

References:
Rollins, H.B., J.B. Richardson III and D.H. Sandweiss (1986), The Birth of El Niño:
Geoarchaeological Evidence and Implications. Geoarchaeology 1:3-15.

Sandweiss, D.H., J.B. Richardson III, E.J. Reitz, H.B. Rollins, and K.A. Maasch (1996),
Geoarchaeological Evidence from Peru for a 5000 Years B.P. Onset of El
Niño. Science 273:1531-1533.

Sandweiss, D.H., C.F.T. Andrus, A.R. Kelley, K.A. Maasch, E.J. Reitz, and P.B. Roscoe
(2020), Archaeological Climate Proxies and the Complexities of Reconstructing Holocene El
Niño in Coastal Peru. Proceedings of the National Academy of Sciences 117(15): 8271–8279.