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.

The First Samoans Project Complete!

Samoapresentation

We’ve completed our project focusing on the early deposits of southeastern ‘Upolu. Below is the non-technical summary or our work:

Archaeological and geological research was conducted along the southeast coast of ‘Upolu Island, Sāmoa over three short field seasons in 2013 and 2014. The goal of the research was to answer the question: where are the earliest Sāmoan settlements? The current earliest settlement is located at Mulifanua and is dated to about 750 BC, near the time that Tonga was first colonised by ancient sailors and perhaps 200 years after Fiji was first colonised. These earliest sites in Samoa, Tonga and Fiji all have a distinctive form of highly decorated pottery called Lapita. While, both Fiji and Tonga have many archaeological sites with Lapita pottery dating to about 950-750 BC, only the Mulifanua site in Sāmoa has Lapita pottery and is this old. A key question for archaeologists is ‘are there more Lapita sites in Sāmoa that are as old as Mulifanua?’ Answering this question is complicated by the fact that the coastlines of ‘Upolu Island have been submerged over the last three thousand years by changes in sea-level and by the geological “sinking” of the island, drawn down by the weight of Savai‘i. Therefore the areas where ancient Sāmoans may have settled at 750 BC may now be offshore and underwater, or buried under metres of sediment. Previous research by geologists indicates that the coastlines of eastern ‘Upolu may have been the least affected by island sinking. Therefore, the research reported here explored this area for 750 BC archaeological sites.
Four archaeological excavations, each 2 x 1 metres in area, and 59 hand-driven auger cores examined the underground deposits along the coastal plain between Lalomanu and Malaelā villages. The geological results indicate that this coastal plain likely did not exist until about AD 800. Before this the area would have been a rocky coast with few or no beaches. After AD 800 relative sea-level retreated and a reef sand beach was exposed. This beach grew toward the current shoreline over time.
The earliest human presence in the area occurs around AD 1400, evidenced by a fire hearth built upon the reef-sand beach, associated artefacts and microscopic plant fossils. The artefact assemblage is small and includes three pottery sherds, a small shell fishhook, broken stone adzes, and stone debris from tool-making. There are also food remains including faisua and other shellfish eaten by Sāmoans, fish such as wrasse and tuna, sharks or rays, and pig. Microscopic plant fossils identified in the archaeological layers show that after humans arrived in the area parts of the forest were burned, likely for plantations, and there was an increase in plants that grow in disturbed forests.
No archaeological sites as old as Mulifanua were found in the study area suggesting that the earliest Sāmoan population at about 750 BC may have been limited to only a few settlements. Limited Lapita settlement may have been caused by a lack of coastal plains on which to build villages, as the coastal plain between Lalomanu and Malaelā in south-eastern ‘Upolu did not form until AD 800. Even after this time, the coastal plain was not used by people for another 600 years

 

And in Samoan:

O suesuega i mataupu tau Talaeli ma Agnuu Tuufaasolo a Samoa faapea le suesuega i le mataupu tau le Eleele, sa faatinoina lea  i Aleipata i le itu i sasae o Upolu, i le tausaga 2013 – 2014. O le manulauti o nei suesuega ina ia mafai ona tali le fesili; Pe o fea tonu le vaega o le atunuu na uluai nofoia e tagata Samoa?

Ua māua i suesuega i talaeli o Mulifanua na uluai faamauina, na uluai nofoia, e tusa ma le 800 TLM,  tusa lea ma le taimi na uluai nofoia ai e tagata folau atunuu o Toga ma Fiti pe tusa ma le 200 tausaga talu ai. O ia nofoaga taua i Samoa, Toga ma Fiti na maua ai ipuele ua faaigoaina o Lapita. E tele nofoaga i Toga ma Fiti sa maua ai ipuele ma pe tusa ma le 800TLM. Na o Mulifanua le nofoaga i Samoa na maua ai lenei ipuele. E le o mailoa i le taimi nei, pe o iai se isi afioaga o Samoa na uluai nofoia e tagata e pei o Mulifanua.  O le taliina o lenei fesili e fai si faigata tele ona o le mea moni e tusa ai ma suesuega i talaeli ma suesuega tau le eleele, ua faalia ai, mai le 3000 tausaga talu ai ua tafia le talafatai o Upolu ma ua  lofia se vaega o le atunuu. O lona uiga o le vaega o nofoaga o Samoa sa uluai nofoia e tagata pe tusa nei ma le 800 tausaga talu ai ua tele ina ufitia e le suasami. O suesuega i mataupu tau le eleele sa faatinoina muamua i le talafai i le itu i sasae o Upolu ua faalia ai e lei magoto tele lea vaega o le atunuu, peitai o loo fai pea i ai suesuega i le taimi nei

E 4 lua sa eli i Satitoa i Aleipata, ma pe tusa ma le lua mita le umi, ae tasi le mita le lautele (2×1), le telē o le vaega na eli. Sa faaaogaina foi le masini faapitoa (hand – driven auger) mo lenei galuega, e eli ai ni pu e 59 i le talafatai o Aleipata mai le afioaga o Lalomanu i Malaela. O le taunuuga o lea elieliga/suesuega ua faalia ai, e lei iai se matafaga i lea vaega o le atunuu talu mai le 800TA sa na o le papa maa sa iai i le talafatai i lea vaega o Samoa. O lona uiga i tua atu o le 800TA na faatoa iai le matafaga mai oneone o le aau seia oo lava ina olaola pea e oo mai i le taimi nei.

O le vaitau na uluai nofoia ai e tagata lea vaega o le atunuu pe tusa ma le 1400TA. O le pinefaamau o lea mau o tainafi sa maua i lenei elieliga/suesuega, o atigi figota, mātau, to’ima’a, o nutigāma’a sa fai ai aupega i aso anamua. Sa maua ai foi atigi faisua ma atigi figota, o ivi ia ma ivi o moa ma puaa. Na māua foi i lenei suesuega ina ua uluai nofoia e tagata lenei ogaeleele na agai loa e fa’ato’a, susunu ma toto ai la’au ua mafua ai ona afaina le eleele lelei sa iai muamua.

E lei iai se nofoaga o Samoa ua umi ma leva ona nofoia e pei o Mulifanua ua faamauina i lenei suesuega, e faailoa mai ai le faitauaofai o tagata sa nofoia lenei eleele pe tusa ma le 800 tausaga talu ai Ua mafua lea tulaga ona o le leai ose nofoaga maualalo i le va o Lalomanu ma Malaela e faigofie ona nofoia e tagata. E oo foi i lena vaitau, e lei toe nofoia e tagata lenei ogaeleele tusa ma le 600 tausaga talu ai.

10 Cores in Two Days!

Coring on Monday and Tuesday in the village of Satitoa in Aleipata District has been quite successful. After consulting with the paramount chief of Satitoa, Matai Togafau Sio, we have freedom to work wherever we like. And with our able assistant Petelu (Peter, centre), Matiu (to left) and I are in good hands.

 

The coring crew! It's really not as bad as they make it look.

The coring crew! It’s really not as bad as they make it look.

We are trying to track the horizontal and vertical distribution of ancient beach sediments and the water table is giving us a headache (pumps will likely be necessary for excavation!). Typically we have swamps to seaward and then a slope break to the uplands. There are some successes with the cores as we locate elevated areas pushing out into the swamp.

 

A mozzie infested coring hell. Fun!

A mozzie infested coring hell. Fun!

Core 8 has abundant charcoal (for a core) in subsurface beach deposits and a nearby core pulled out this possible artefact from the same layer (colleagues, please confirm: abraded pencil urchin spine?). These subsurface beach deposits are probably not Lapita in age, but I’ve got charcoal to date…

Is this an abraded pencil urchin spine?

Is this an abraded pencil urchin spine?

Over the next few days we will move south towards Vailoa village where there is less swampy ground between the current shoreline and possible ancient dunes—the topography here may prove fruitful.

 

Not a bad place to eat lunch

Not a bad place to eat lunch