A week of rain, survey and coring in Falefa, Samoa

Nick Porch examining a D-section core. Bugs in there will tell us about ancient ecosystems. Photo by Ron Lloren.

Our third week in the field was taken up with a variety of projects: working in the crater lakes to extract paleoenvironmental cores, continuing to map drainage ditches in Falevao and more D-section coring in Falevao. Plus we had several rain days.

We’ve now mapped an impressive network of ditches in Falevao and these mostly seem to connect to the river and likely served to channel water off the plantations during river flooding—we’ll do an elevational and hydrological analysis to test this idea.

Crossing the river to get to a coring site. Photo by Ron Lloren.

PhD student Ron Lloren from the Swiss ETF (Institute of Technology) is here to collect water samples for Hydrogen isotope analysis. The proportion of H isotopes in various water bodies can tell us about periods of aridity over millenia. We’ll correlate these data with our work on the field systems, flora, and insect fauna to generate as complete a picture of changing ecosystems as we can.

Ron takes rain water samples every day to get a baseline Hydrogen isotope signature.

Falefa survey area. The blue feature is a large walled walkway. The red features are single rock walls.

We’re now in our last week or so of fieldwork and back to Falefa mapping landscape features, including massive walled walkways that predate living memory and perhaps represent early divisions of the landscape. Excavations next year will help us determine this.

What one does on Sunday. Photo by Ron Lloren

More on the Land and Agriculture Marsden Project

We’ve recorded mostly walls (yellow) in Falefa near the coast and ditches (pink) in Falevao inland. There are different agricultural strategies depending on local environment.

Our second week of field work had us training another set of NUS Centre for Samoan Studies students, boys this time. We moved inland a bit to survey the lands of Falevao village (some of our Falevao survey area is the banner image), primarily noting and correcting drainage ditches identified in lidar.

We recorded a “fortified site” or at least a set of ridgeline features with platforms, terraces, and “umi ki”. It’s not on any of the Green and Davidson maps, so there’s still some discovery left out there.

Dr Matt Prebble getting ready to face this river section.

We’ve also been facing river sections and taking charcoal and sediment samples. There is a consistent burn layer at about 1.2 m deep across the area with massive charcoal chunks suggesting a big burn of forest. We’ve also found coconut and candlenut endocarp and seeds in the burn layer.

There is a similar burn layer in nearby by Fagaloa Bay that we recorded last year with breadfruit charcoal, and which dates to about 1000 BP.

Taking a break with Dr Brian Alofaituli, student Loto, assistant Pena, and me.

An interesting question for Falefa: why would populations burn off a presumably productive forest? Perhaps (raised-field) taro agriculture became more advantageous? We’ll return to this area in the upcoming weeks for D-section coring and more sampling. Dating should be interesting as well.

Speaking of D-sections: we hiked into a crater yesterday (on maps, Mt. Savaii) to take cores for pollen, micro- and macro-fossils, invertebrates and other goodies to begin reconstructing the paleoenvironment. It was a successful day with an easy 4 m core. We’ll go back to get down to 5 m and do some more collecting.

The D-section extracts sediment in intact 50 cm sections for later analysis.

For the next two weeks we’ll be making more GIS based maps and coring several locations, all to ultimately figure out the processes that explain agricultural and socio-political change in ancient Samoa.

Marsden Research on Ancient Samoan Agriculture and Political Complexity

We’ve kicked off field work for our research on the development of Samoan agriculture and political complexity in the Falefa Valley, ‘Upolu, working with the villages of Falefa and Falevao. Last week Associate Investigator Matt Prebble and I had National University of Samoa Students working with us as part of their HSA380 Field Archaeology course. The upcoming week we will have a new batch of students on the course. University and Centre for Samoan Studies staff, lead by Matiu Matavai Tautunu and Dionne Fonoti, have also helped behind the scenes and in the field.

Samoan archaeology student Vinimua captures the discussion of something important over there.

Our first goals is to map the extent of agricultural features such as rock walls, ditches, and terraces through a combination of lidar-based feature extraction and ground-truthing. We are working with the feature extraction data produced by Associate Investigator Seth Quintus at the University of Hawaii. With our field data, Seth should be able to tweak his extraction procedures to get better results. One obvious issue we are encountering is the use of rocks from old walls to build new structures. The old wall are visible in the field as exposed base-courses, but don’t show up very well in the lidar.

Samoan archaeology student Rachel records a rock wall.

We use a combination of Bad Elf GNSS Surveyor units, bluetoothed to iPads with ArcGIS Collector to collect field data. This is a really slick system and allows us to upload data every day to our ArcGIS enterprise cloud where Seth (currently in Hawaii) can check on our work, offer advice and ask for corrections. The Bad Elfs are working surprisingly well. I was nervous about their accuracy in heavy canopy, but they are consistently getting sub-5 metre accuracy and down to a metre or less with clear sky. Trimble has got a serious competitor here.

Some of the features recorded thus far include walls, starmounds, and stratigraphic relationships.

Our field data after just five days at work is pretty extensive. Although the valley is huge, I think that after a couple more month long sessions over the next year we will have generated an impressive amount of spatial data on agricultural infrastructure.

It’s hot surveying in the Samoan bush.

In a little over a week’s time we will be working with the D-section corer in the inland lake-caldera. For more check out the Centre for Samoan Studies, Research Gate, Google Scholar and Twitter.

Recording Ideas for Marsden Falefa Project

Seth Quintus, Mat Prebble and I have been planning upcoming field work associated with our Marsden project in association with the National University of Samoa, Centre for Samoan Studies (https://samoanstudies.ws)

One direction we will likely travel is down the path of full digital recording with iPADs/tablets and various GPS technology. This article in Internet Archaeology http://intarch.ac.uk/journal/issue47/1/index.html is informative, to a degree, but also bogged down in “reflexive”-speak. However, access to various levels of recording in real-time has great promise.

 

 

 

 

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.

Land and Agriculture in Samoa

Here’s the 100 word summary of my recent grant submisstion:

“Despite being the archetype of socially stratified and hierarchical ancient cultures, we do not know how the Polynesian chiefdoms arose from less complex societies. The untested orthodox theory proposes that innovations in land tenure and agriculture lead to chiefly control of populations. Our international team will test this theory through new drone-based mapping and innovative soil analyses that track changes in land boundaries and agricultural productivity. Our research will discover the origins of the Polynesian chiefdoms with significant results for explanations of Polynesia prehistory, the functioning of stratified societies, and the global rise of persistent, institutionalized inequality.”

Falefa viewed from Lemafa pass.

This is very much a LKFS type of project where we will try to determine the chronology of agriculture and different types of land use in Falefa Valley, ‘Upolu, Samoa. My grant collaborators are Seth Quintus and Matthew Prebble.