Surveying and Excavating Ancient Samoan Agriculture

We’ve been back in Samoa for a few weeks now surveying in rock walls, mounds and other likely agricultural features, some of which are identified on lidar map by Dr Seth Quintus, as part of our Marsden funded project investigating agricultural variation and socio-political complexity in the past.

Survey involves transects across the landscape, recording characteristics of features to add to the lidar and GPS based GIS that we are building. We use these data to detect and explain patterns of agricultural infrastructure over time.

Alex Queenin recording a stone wall. Many of these features, like this one, have had the ancient stones removed to make new walls.

We have also begun excavating features recorded last year. Our primary goal is to recover datable material, so we can begin to build a chronology of construction in the Falefa Valley. We will add more features and different types of features as we continue this year and next.

A rough 3D model of a walled walkway stretching across several hundred metres of the Falefa Valley.

3D model of the walled walkway after excavation of layer 1, feature rocks and associated sediment.

3D model after excavation of layer 2, a deposit associated with feature construction with some feature rocks embedded within it.

3D model of the base of excavation showing continuation of layer 3, a more orange sediment that had charcoal flecking at the top, predating wall construction and with abundant natural eroding basalt boulders and cobbles.

We’re getting great dating material from these excavations, so I’m confident are analyses and results will have much to contribute to Samoan archaeology and studies of agriculture and social complexity.

Hiding out from the rain under a banana leaf.

What explains the differences in the ancient socio-politics of Samoa and Tonga?

Why did Tonga form a single paramountcy (later a tripartite one) while Samoa became several (presumably competing) chiefdoms? We are pretty sure the colonising/early demography of Tonga and Samoa was different (Rieth and Cochrane 2012; Cochrane et al. 2013, 2016; Cochrane and Rieth 2016; Cochrane 2018), so is this early difference key? Does this continue with later demographic patterns in the two archipelagos? Are these differences related to variation in agriculture and other subsistence strategies between Tonga and Samoa (Quintus and Cochrane 2017, 2018)?

After surveying a gigantic mound in Saoluafata (Pule, Aumua Matiu, Ethan). February 2019

How can we begin to tackle these questions through archaeology?

  1. Our Marsden funded research is a start. With this project we are investigating the development of agriculture in the Falefa Valley, Samoa, focusing on the timing of field development and drainage ditch systems, environmental variation, human-induced changes and the rise of corporate or monumental structures.
  2. Agricultural terraces are a big question–ie, there are lots of terraces on the lower slopes of mountains bounding Falefa and it is not clear if these were agricultural of for some other purpose. And of course the use of features can change.
  3. Identifying variation in socio-politics is part of the problem as well. Having Just read Quintus’ and Clark’s (2019) pigeon mound article make me think of…mounds. What could a survey of mounds, description and classification of these structures in Falefa tell us? What evolutionary and transmission processes explain their variation? Can they tell us about changing socio-politics, group formation in Samoa?

Rieth, T. M., & Cochrane, E. E. (2012). Archaeological Monitoring and Data Recovery in Support of the Federal Emergency Management Agency Permanent Housing Construction Program, Tutuila Island, American Samoa. Retrieved from International Archaeological Research Institute, Inc. Honolulu, Hawaii: 

Cochrane, E. E., Rieth, T. M., & Dickinson, W. R. (2013). Plainware ceramics from Sāmoa: Insights into ceramic chronology, cultural transmission, and selection among colonizing populations. Journal of Anthropological Archaeology, 32(4), 499-510.

Cochrane, E. E., Kane, H., Fletcher, C., Horrocks, M., Mills, J., Barbee, M., . . . Tautunu, M. M. (2016). Lack of suitable coastal plains likely influenced Lapita (~2800 cal. BP) settlement of Sāmoa: Evidence from south-eastern ‘Upolu. The Holocene, 26(1), 126-135.

Cochrane, E. E., & Rieth, T. M. (2016). Sāmoan artefact provenance reveals limited artefact transfer within and beyond the archipelago. Archaeology in Oceania, 51(2), 150-157.

Quintus, S. J., & Cochrane, E. E. (2017). Pre-Contact Samoan Cultivation Practices in Regional and Theoretical Perspective. The Journal of Island and Coastal Archaeology, 1-27.

Cochrane, E. E. (2018). The Evolution of Migration: the Case of Lapita in the Southwest Pacific. Journal of Archaeological Method and Theory, 25(2), 520-558.

Quintus, S., & Cochrane, E. E. (2018). The Prevelance and Importance of Niche in Agricultural Development in Polynesia. Journal of Anthropologial Archaeology, 51, 173-186. 

 Quintus, S., & Clark, J. T. (2019). Ritualizing Hierarchy: Power Strategies and Pigeon Catching in Ancient Samoa. Journal of Archaeological Research, 0(0), 000-000.

Archaeology at Tiavea-tai

Jack Golson worked at Tiavea-tai in the 1960s and we returned last year to explore the deposits that Jack first identified.

Tiavea-tai beach ridge.

We dug a couple of 2 x 1 m test pits and several cores to identify basic stratigraphy. Excavation results were similar to our work earlier in the year, and in 2016, at several sites in Fagaloa. Deposits appear to be in the range of 400-600 years old, lack ceramics, and in relative terms, represent fairly low-intensity occupation (compared to, say, Tula, on Tutuila).

Flying the old IARII colours as I stand in a pit.

This makes me think that there may be low-intensity, late occupation of the northeast  and east ‘Upolu coastline from Fagaloa to Lalomanu, in line with Cochrane et al., 2016 and Kane et al. 2017.

Dr Mat Prebble standing next to a rock wall at Tiavea-tai, an abandoned village in northeast ‘Upolu

Cultural Evolution Society 2017 conference, Jena, Germany

It’s been a week since the end of the inaugural CES conference in Jena, part-hosted by the Max Planck Institute for the Science of Human History. It was great to be at a conference where everyone was playing with the same rules: evolution is a general framework used to explain human and animal behavioural and artefact variation. I’m not sue how much CES differs from the Human Behaviour and Evolution Society meetings (HBES).

Ethan talking about evolution and agriculture

I gave a talk with my co-author Fiona Jordan that was well-received. We use Bayesian phylogentic analyses to examine the evolution of agricultural traits in the Pacific. Major conclusion thus far: new environments encountered in Polynesia explain the radiation of diverse techniques.

Ethan Cochrane, Joe Brewer, and Jamie Tehrani talking shop.

A highlight of the conference was seeing old colleagues and meeting new ones. The excellent German beer and food didn’t hurt.

Next year’s conference will be in Tempe, Arizona, at ASU. I encourage more archaeologists to attend, especially those interested in macroevolutionary studies, as these were somewhat lacking in Jena.