Wednesday, March 28, 2007

34 bags of sherds

34 bags of potsherds. 87.2 kilos, 10,373 individual sherds. These ceramics came out of a single excavated level behind the house in unit 307. Although we haven’t calculated the density yet, this batch surely sets a new record for my fieldwork in Mexico for the amount and density of artifacts from a single deposit. This was an especially rich midden contained in a pit excavated into the sterile clay that underlay the house and the terrace it sat on. Unit 307 was excavated by Jeff Sahagun (ASU) and Marieke Joel of Berlin. In the photo Marieke shows 31 of the 34 ceramic bags.

This deposit is one of the most important we have excavated so far, not only because of its artifact density. The pit contains a stratified deposit with an apparent Middle Postclassic layer at the base, then a Late Postclassic layer (the 34 bags plus a couple of other levels), and finally a layer with Spanish colonial artifacts at the top. The development of a Postclassic chronology is one of the major goals of the excavation, and this deposit has our best stratigraphic sequence to date. We have many deposits with Late Postclassic ceramics, but very few with clear Middle Postclassic materials. The colonial levels at the top are interesting—they contain almost exclusively Late Postclassic ceramics (plus only a couple of sherds of glazed earthenware), with several ceramic figurines that depict Spaniards. This house was apparently occupied from Postclassic times into the Spanish colonial period, but the occupants only added a few colonial objects.

The remains of this house, like the structure excavated as unit 309, were very close to the ground surface, and recent plowing of the field had disturbed the walls and floors. But we were able to map a number of the walls and we recovered nice domestic artifacts around the structure. Although from a scientific perspective it’s great to have such heavy artifact deposits, from a logistical perspective it’s a pain in the neck right now. We have just about outgrown our field lab capacity, and we will soon have to start carting sherd bags off to our permanent lab at the Colegio Mexiquense. We are heavily backed up in sherd washing (we recently hired more washers) and we are way behind in artifact processing. At Yautepec in the 1990s we excavated more than one million sherds in a 6-month season, and we seem to be on a similar track here at Calixtlahuaca.

Saturday, March 24, 2007

An ancient house: excavation 309

This structure, and that uncovered in excavation 307 (stay tuned), are the first Postclassic houses to be excavated in the Toluca Valley. We didn’t know whether to expect the small, one-room houses we had excavated in Morelos, or the larger, multi-roomed structures found at Aztec sites in the Valley of Mexico. In size and complexity, the house in unit 307 turned out to be closer to the latter pattern. Unfortunately, the structure was not buried very deeply and it had been damaged by plowing in recent decades. This was a fairly rapid excavation due to a deadline imposed by the landowner. It was supervised very ably by ASU graduate student Angela Huster.

The photo shows us uncovering the central part of the structure. Stone rubble covers a central earth floor. On the north and east sides of the structure (farthest away in the photo) are stone pavements made of large, rectangular slabs. For a number of reasons, we think that these were exterior patio areas rather than interior rooms. There were three distinct stages of superimposed stone pavements, of which only the final stage used the large well-made slabs. We are hoping that the ceramics found below and between the floor will help us work out a chronology for the site.

After this picture was taken, we found a separate room that opened out to the west (right side of the photo). The stone rubble that covers the central floor in the photo consisted mainly of building stones—both cut and unfinished stone—from the house walls. But the rubble also included a large number of architectural ornamental stones. The photo shows column bases and cones (called “clavos” in Spanish) that were used for decoration in Aztec elite residences and temples. Was this the house of an elite family? Only continuing analysis of the architecture and artifacts will tell.

Friday, March 9, 2007

We finally found some houses to excavate

Since the main goal of this project is to excavate houses at Calixtlahuaca, it was frustrating when we did not locate any houses in the first few weeks of fieldwork. But all of a sudden, we are working on two large and complex structures. The landowner will soon plant the field containing the houses, and in order to get his permission to dig I had to promise to be done and backfilled by March 20. This does not give us much time, and the architectural remains just keep going (typically under the back dirt pile. This is one clause of Murphy’s Law of excavation; another deals with important finds made at the end of the field season).

The field is on a gentle slope below the site museum at the base of Cerro Tenismo. In the 2006 survey we noticed a heavy concentration of artifacts in the field. There are several areas that look like they may have been artificially leveled off. We placed a trench in the middle of two of these and immediately hit architectural remains. The lower area (unit 309) has a large pavement of nicely cut stones (see the photo), with several rooms or features on the upslope side. One room (being cleared on the left side of the photo) has a nice floor of rectangular stones and walls of thin cut stones. To the right of this is a rectangular area covered with rough stone rubble. This may be the remains of walls; we haven’t removed the stones yet to look for a floor or other features. The pavement and some walls continue to the right under the backdirt pile.

The upper area (unit 307) also has a rectangular area of stone rubble, with a nice double-row foundation wall on the left and some large paving stones (probably an exterior patio) on the right (see photo). This afternoon we uncovered some rough walls near the top of the photo, lower in elevation that the pavement; perhaps these are the remains of an earlier structure.

It is still too early to plot the full extents of these structures. We hope we can uncover their entire areas, draw and photograph everything, and also locate and excavate some household trash deposits associated with each one—all before we have to stop on March 20. We have another reason to complete excavation by that date. On March 21 (the spring equinox) there will be festival at Calixtlahuaca that combines new age mysticism with a celebration of indigenous peoples of the State of Mexico (this seems an unlikely pairing to me). Thousands of visitors are expected, and we don’t want to have open excavations near the center of the site.