The excavations at the Inka settlement around the Pumapunku pyramid have been going very well. In the previous update, I mentioned that occupations from the Colonial period were slowing our progress down to the Inka levels. Two weeks ago we finished recording the Colonial features, which consisted of small clusters of charcoal and burned llama and sheep dung, called taquia, that represent the remains of cooking fires. There were also a few small walls, remains of Colonial structures. We found some Colonial features on top of the collapsed walls of the earlier Inka structures. The Colonial occupants also reused Inka buildings that were still standing, and we found three occupation surfaces in these structures. The lowest surface was a compact earthen floor with areas of charcoal and ash from cooking fires, scattered Inka ceramics, some llama or alpaca bones, and the remains of meals. The next two surfaces were similar but contained fragments of pottery that were finished, though not shaped, like Inka ceramics. Other artifacts we found here included a silver needle and an iron nail, both of which were items introduced by the Spanish and allowed us to date the two subsequent occupation surfaces to the early Colonial period. We plan to look closely at the ceramics from these layers to study how traditional ceramic technologies were transformed by contact with the Spanish and the socio-political changes that followed the Spanish Conquest.
As we moved below the Colonial occupation, we found evidence to support our hypothesis that the area was a feasting facility. There are four relatively large rectangular structures that have the form of kallankas, Inka feasting halls. Inside one of those buildings, we found an amazing refuse deposit of very large fragments of Inka ceramic vessels, lots of charcoal, and many animal bones (mostly llama but also other animals, including a bird). The ceramics were mostly cooking vessels covered with soot and highly decorated aribalos, vessels used for storing and serving chicha, the corn beer that was a necessary part of Inka feasts.
We found similar deposits of refuse from large-scale food production in one of the wide corridors that run between the rectangular structures. Our excavations and the ground-penetrating radar (GPR) survey show that there is a large open area ideally suited for ceremonies or public rituals just east of this area. The passageway leading from the food-preparation area into the plaza area is marked by a double-jamb doorway, a kind of doorway within a doorway that typically marks the entrance to ritually or politically charged spaces in Inka settlements.
We have been fortunate to have the skilled assistance of Kimberly Henderson, from the University of Denver, who has been conducting a ground-penetrating radar survey around the Akapana. She brought the GPR instrument over to the Pumapunku and set up several grids to systematically survey. This technique works by sending a signal into the ground and then detecting its differential reflection back to an antenna. Denser objects create anomalies in the signal, and by tracing them we can detect walls and other buried features. In an area we suspected was a large plaza, Kimberly's instrument found no anomalies that looked like architecture, while in several other areas she found signals that look like buried walls. We will be expanding our GPR survey in the next few weeks and will try to test some of these anomalies.
The weather has been a bit uncooperative during the last few weeks. We're in mid-winter here and, although we're technically in tropical latitudes, the elevation of 3850 meters (12,600 feet) above sea level negates the effects of being close to the equator. It's been cold and windy, and we've also had several days of snow. We work through some of the light snows, but the heavier snows make it impossible. Drawings get wet, features in units get covered, and melting snow makes it impossible to excavate our trenches with the care they require. On those days we've covered the trenches and worked in the lab instead, going over notes and analyzing artifacts.
We began our lab work last week. All season, we've had two crews washing all of the ceramics, bones, stone artifacts, and other materials that we've been recovering. Tamara Bray of Wayne State University has joined us to analyze the ceramics we have found so far. We also started processing our flotation samples, ten-liter samples of earth from all of the occupation surfaces, floors, garbage pits, and other contexts. In our flotation device, a modified 55-gallon drum, the earth is agitated by a current of water, and all the carbonized material (seeds, charcoal, thatch, etc.) floats to the surface of the water. Heavy objects in the sample (rocks, pieces of ceramic, stone flakes, bone shards, etc.) sink and are caught on a fine screen mid-way down the drum, while all the fine clay and silt sediment settles to the bottom. By identifying the different kinds of plants in the samples, we can discuss the diet of the inhabitants of the site, the kinds of wood and thatch they used to construct their buildings, and the kind of wood they burned to cook their food. The small artifacts collected in the flotation sample--too small to be collected during normal excavations even with screening--allow us to examine the kinds of activities that occurred in different areas of the settlement in more depth.
This week we began taking photographs of our completed excavation units with a photo tower we made last year. It raises the camera eight meters (26 feet) so we can photograph the entire surface of our excavation units, which is otherwise nearly impossible. It's always an adventure to use the photo tower, because we have to coordinate between a dozen people or so--the people who stabilize each leg, the person who raises and lowers the camera on a pulley, the people who stabilize the camera using guy wires off the four corners, and the person working the camera. We have a 20-second timer on the camera, so we have just enough time to trip the shutter, raise the camera, and steady it at the top of the tripod before the shutter opens.
Another cooperative task has been removing some of the very large blocks that were thrown down the side of the Pumapunku pyramid by Colonial looters. The blocks, which no longer bear any relation to their original place on the pyramid, are overlying the Inka remains and hindering our excavations. After we drew, photographed, and numbered each stone we moved them. This was quite a challenge as some weigh over a ton! It was quite a team effort, with up to 25 people pulling and pushing. Using rawhide rope and wooden levers, we managed to slide them out of our excavation trenches and out of the way. Hopefully our solution to rock moving will also prove of use in the totora reed boat experiment, in which Paul and Chris are trying to transport a much larger block.
Although we've been working hard, it hasn't been all work and no play. On July 16 we celebrated the anniversary of the founding of La Paz. Like Independence Day in the U.S., this is a day of parades and patriotism. In cities and towns across the altiplano of Bolivia, all of the schools, community groups, and professional associations participate in parades. The modern town of Tiahuanaco was no exception, and our project and its personnel contributed to the festivities. We bought several drums and flags to complement the sampoñas (Andean panpipes) we purchased for last year's parade, and we all got dressed up and marched. We had a great 20-piece band composed entirely of our project members, who played Andean tunes to accompany our marching.