Lab Work Update

Hi all!

Apologies for the long delay between posts, but things have been busy in the lab!

As of yesterday, we have finally (FINALLY!) finished washing, drying and carrying out the preliminary catalog of the material recovered during the 2011 field season.

Over the last couple of months, I have washed and cataloged during the week while Angel Mario, Walter and more recently, Jonathan (local community members and farm workers participating in the project) have joined me to lend a hand on weekends.

Washing mainly entailed scrubbing thousands and thousands of ceramic sherds. Not terribly exciting, but a necessary step, that can be interesting as one reveals diagnostic decorative elements hidden under caked on dirt. Washing also helps give a sense of what kinds of materials are found in the different units, and allowed me to actually handle/briefly examine practically all the ceramic artifacts recovered, something almost impossible to do in the field when multiple test units are being dug at once and one is under pressure to maximize actual digging time.

None of the bone recovered was washed, only dry brushed, as it is all in a very poor state of preservation due to the very marked wet/dry season, the coarse/abrading nature of the volcanic deposits and the slightly acidic soil present on the volcano.

None of the lithic artifacts were washed either, in order to improve the recovery of starch and/or phytoliths from the surfaces (and adhering soil) of the various obsidian blades and groundstone manos and metate fragments recovered. These artifacts will be washed in a controlled lab setting at Stanford next year in order to recover as many of these remains as possible.

Very little metal was recovered, most of it nails, although we did find what appears to be a fragment of a lead shot in Test Unit 16 (see image below). Metal artifacts were not washed, but simply dried, separated and re-bagged in clean bags.

Possible lead shot fragment?

The cataloging we carried out is a very basic one. After washing, the material is left to dry for at least 2 days (usually 3-4), after which we separate, count and weigh all the artifacts by material categories (ceramics, lithic, groundstone, carbon, metal, structural [mainly bricks, roof tiles, daub, etc], glass and bone).

Now for some site stats!

Over the course of the 7 week field season, we (a crew of about 4 people) excavated a total of 14 2x1m test units, the majority of which (10) reached to at least a meter in depth, with some going down to 2m.

These test units yielded:

Ceramics: 11,613 sherds, weighing 109.3 kilos

Lithics: 80 mainly obsidian blades, fragments, etc weighing 336.7 grams

Bone: 445 (mostly small pieces) weighing 871.2 grams

Carbon: 748 (mostly small fragments) weighing 213.6 grams

Groundstone: 8 (fragments of manos and metates) weighing over 2.17 kilos

Metals: 31 fragments (mostly nails) weighing 127.2 grams

Structural: 77 fragments of bricks and roof tiles, etc weighing 3.94 kilos (note: this is only a sample of bricks and ALL roof tiles, daub etc encountered. Sector 3 yielded so many brick fragments due to the extensive brick patio located there, that we took only a small sample).

Based on this, it is pretty clear why ceramics will play a large role in the project and in my dissertation research in particular!

I’ll be posting up some more stats broken down by Test Unit and Strata in a new update, as well as giving some info on the next big step in lab work that is already (a month or so) in progress (thanks to Heather Law Pezzarossi): the ceramic analysis! At this point the ceramics from Test Unit 17 are almost completely analyzed and they have served as the starting point for the ceramic paste, attribute and type analysis for the project. Details on this next time.

Thanks for reading and a huge thanks to all (Heather, Isolda, Natalia, Corey, Cristina) that have pitched in with the washing and other phases of lab work over the last couple of months.

More soon!