Upland Forts, Paleobeaches, and no Lapita.

It’s almost all over for us here in Aleipata, investigating the coastline’s prehistory. Our final archaeological test pit uncovered the paleobeach we’ve been seeing in most places, with a silty-sand layer on top that had a few midden shells, a lithic, and a piece of plainware pottery.

I think that's a pretty nice looking paleobeach. Coring down through this after excavation we got to a layer with increased basalt sands suggesting we were approaching the Pleistocene bedrock.

I think that’s a pretty nice looking paleobeach. Coring down through this after excavation we got to a layer with increased basalt sands suggesting we were approaching the Pleistocene bedrock.

We’ve made a pretty good go of it: four 2 x 1 m controlled units, about 60 auger cores (since 2013). We are consistently getting a thin cultural layer with minimal artefacts and plainware pottery on top of carbonate beach, likely on top of basalt (Pleistocene?) bedrock. If the UH geologists come back with a mid-holocene date for the subsurface beach this will *suggest* that there were no Lapita-bearing populations here, even though the landscape was available. Pretty interesting stuff.

Panoramic view of the human-made embankment stretching across a ridge between two drainages. This is about a kilometer inland from Satitoa Village in the uplands

Panoramic view of the human-made embankment stretching across a ridge between two drainages. This is about a kilometer inland from Satitoa Village in the uplands

We went inland today to explore possible upland deposits and came across a great ditch and bank system that was likely defensive. These are found all over Samoa (and elsewhere) and may date to the last 1000 to 500 years.

The University of Auckland archaeologists and University of Hawaii geologists. Front left to right: Haunani, Shelly, Shelia. Back: Mana, Joe, Matt, Matiu, Ethan, Alex, Chip (note hand).

The University of Auckland archaeologists and University of Hawaii geologists. Front left to right: Haunani, Shelly, Shelia. Back: Mana, Joe, Matt, Matiu, Ethan, Alex, Chip (note hand).

Pottery and Fishhooks!

The University of Hawaii geologists left today and we set up an excavation unit next to their geological pit as they found an adze fragment and shellfish midden in a shallow layer above the paleobeach.

The happy excavation crew at SAT-3, Test Unit 1.

The happy excavation crew at SAT-3, Test Unit 1.

This is a tough excavation as the water table is in a bad place–the silty sand layer right above the sand–and this is very difficult to pump adequately due to the silt, and get somewhat dry sediment for excavation. We were able to get through the silty sand onto sandy loam which is the top of the (likely) earliest calcareous beach identified by the geologists.

Nice shell fishhook found by Shelia Warren (NUS) in the screen/sieve.

Nice shell fishhook found by Shelia Warren (NUS) in the screen/sieve.

When excavating in this mess it is impossible to get very good vertical provenience, but the pottery and fishhook come from the bottom of the silty sand, so on top of the beach. The pottery suggests a deposit at least 1000 years old, but we will see.

Some (non-Lapita) pottery from our Satitioa Village excavations.

Some (non-Lapita) pottery from our Satitioa Village excavations.

This is what the water table does to sidewalls.

This is what the water table does to sidewalls.

 

 

Things are getting clearer.

Prof. Chip Fletcher’s coastal geology crew has been with us in Aleipata for a few days now and things are getting clearer. We’ve found a likely mid- to late-holocene beach at the bottom of our test excavations. Chip has also found this in his cores and in places this is over stream gravels, so we possibly have the entire marine transgression-regression sequence.

Prof. Chip Fletcher from the University of Hawaii School of Ocean and Earth Sciences and his crew placing geological cores to track the distribution of a putative mid to late Holocene beach. Chip's on the core with assistant Daniel. Graduate students Haunani Kane and Shelly Habel describing sediments. Post-doctoral researcher Dr. Alex Morrison surveys the scene.

Prof. Chip Fletcher from the University of Hawaii School of Ocean and Earth Sciences and his crew placing geological cores to track the distribution of a putative mid to late Holocene beach. Chip’s on the core with assistant Daniel. Graduate students Haunani Kane and Shelly Habel describing sediments. Post-doctoral researcher Dr. Alex Morrison surveys the scene.

Joe Mills and Matt Barbee (with Chip’s crew) are mapping the coastal flat surface and core elevations. The goal is to produce a subsurface map of the sand layer. This will also be dated by shell and carbonate sands.

Midway through excavation of our second test unit. Alex Morrison and assistant Junior survey my handiwork. Always good to have a table for excavation

Midway through excavation of our second test unit. Alex Morrison and assistant Junior survey my handiwork. Always good to have a table for excavation

Alex and Ethan pumping out water of a really deep hole. There is the sand layer at the bottom of all that muck.

Alex and Ethan pumping water out of a really deep hole. There is the sand layer at the bottom of all that muck.

We’ve completed a second 1 x 2 meter test unit. This one went down 260 cm before hitting the sand layer, and this was underwater. Alex Morrison and I, with the help of Mana Laumea and Sheila Warren (National University of Samoa) pumped this bugger out  and retreived sand samples, although no artefacts and not way to see if there are features on top of the sand as in the first test unit.

What are they doing in that deep hole?

What are they doing in that deep hole?

So my current hypothesis is still that there was a beach at Aleipata around 1000 BC, but that very few people were here. The test will be the dates we get from that subsurface beach layer…guess we have to wait a month or two.

One test unit complete. Interpretation: few people in Aleipata…

Finished off our first Aleipata test pit today. First time I used a pump as well. I must say the pump mechanics and generator worked really well, but it is difficult to pump out a 2 x 1 meter unit in sand and still successfully excavate. We were able to get about 20 cm below the water table fairly easily, but after that…the problem was not enough water to keep the pump running all the time.

170 litres a minute of pumping action.

170 litres a minute of pumping action.

We went down through several layers onto silty sands with evidence of human occupation (a nice fire feature), but no other artefacts to speak of. These deposits were on top of culturally sterile beach sand.

See that nice fire feature resting in the basal sand deposit?

See that nice fire feature resting in the basal sand deposit? The upper sand deposit is the 2009 tsunami.

Now there could be cultural deposits beneath this (anything’s possible), but I really doubt it. I think in Aleipata we have a sparsely occupied coast in the post-ceramic period in Samoa and perhaps even lower density (any?) occupation prior to this. Chip (Charles) Fletcher and his team from the University of Hawaii are coming to visit next week to investigate just this idea of an inhabitable coast. More on this later…

The crew going about there business.

The crew going about there business.

We begin excavation in new area next week.

The end of another day.

The end of another day.

First excavation in Aleipata!

We completed two days of excavation on one of our more promising locations (based on last year’s cores). Down to just above the water table in out 1×2 unit and tomorrow we will probably get out the generator and pump.

Mana Laumea rippin' out Layer III! (bonus points for wearing a lavalava during excavation). That clean white sand is the 2009 tsunami deposit.

Mana Laumea rippin’ out Layer III! (bonus points for wearing a lavalava during excavation). That clean white sand is the 2009 tsunami deposit.

We’ve also begun total station survey before Chip Fletcher and his crew arrive from the University of Hawaii (SOEST).

Joe Mills teaching Mana Laumea and Sheila Warren (National University of Samoa) how to use the total station. Joe and Mana are apparently having a "hands on hips" competition.

Joe Mills teaching Mana Laumea and Sheila Warren (National University of Samoa) how to use the total station. Joe and Mana are apparently having a “hands on hips” competition.

We’ve had great support from Satitioa Village and Taufua Beach Fales, and the Centre for Samoan Studies of the National University of Samoa. Also check out twitter feed by Joe Mills: @OBearded

Not a bad place to download the day's survey data and play with ArcGIS.

Not a bad place to download the day’s survey data and play with ArcGIS.