Over two months have passed since we finished our field investigations in Summer 2004. The end of the field season was very hectic. A major focus of our field research was excavating the interior of “Building 1” – a stone foundation for an adobe house. This July we discovered that the stone foundation is not the only building that once stood at El Polín Springs. Beneath the foundation lies the rubble from an earlier adobe building. Through our excavations this summer, we learned that this earlier adobe building was destroyed, at least in part, through some kind of fire. The heat from the blaze was so strong that it changed the color of the soil beneath adobe building. We still don’t know the dates when the earlier and later buildings were occupied – but we will be trying to answer that question through our laboratory research this academic year.

In Summer 2004 we also continued our excavations in the midden deposit just south of the adobe buildings. Here, too, we found that the deposits are much more complex than we ever imagined. We found that the west hillside of El Polin Springs had been substantially altered during the Spanish-colonial/Mexican period. A large pit, measuring at least 10 meters by 20 meters in diameter, was excavated into the side of the hill. We are guessing that the pit was probably excavated to retrieve clay soils, either for making adobe bricks or for some kind of earthworks like a small earthen dam. Later, people living and working at El Polín Springs through their household refuse into the pit. We found a wide assortment of artifacts – charcoal, cattle bone, ceramic sherds, and glass bottle fragments – in this deposit.

Because the house beneath Building 1 burned in a fire, the soil around it and its adobe bricks were fired the way that pottery is fired in a kiln. Our featured artifacts for this update are the lump-like clumps of fired terracotta and earthenware that resulted from the blaze. We named this artifact type, “Amorphous Fired Clay” (AFC), and during our field investigations classified it based on its hardness and color. We estimate that the fire reached temperatures of about 1000-1250° Celsius.