Just What is in a Trash-Filled Storage Pit?
Posted On: 04/19/2018 - 12:32pm, Posted By: Bob Genheimer, Curator of Archaeology
If you’ve ever wondered why it takes so long to process and catalogue the contents of a prehistoric trash-filled storage pit (TFSP), this blog entry on a single TFSP from the Hahn site, may give you a clue.
Most Hahn TFSPs began their life as storage locations for food items, and many probably served as underground silos for the storage of maize, the agricultural staple of this Late Prehistoric (ca. AD 1300-1625) village site. Below ground pits would have been critical for the storage and protection of foodstuffs, particularly in the winter when only stored maize was available and hunting was less productive than in warmer months. At some point, perhaps when the pit became infested with vermin, insects, or mold, the pit was abandoned as a storage receptacle. It was then filled, relatively quickly, with trash or waste from cooking, butchering, flint knapping, and tool and vessel breakage.
Figure 1: Location of Feature 261 (anomaly C5) on magnetometry map of western portion of the Hahn site. The majority of roughly circular anomalies represent pit features. Magnetometry and mapping courtesy of Jarrod Burks.
Figure 2: Museum volunteer Andi Roth completing excavation of western half of Feature 261.
Let’s take a close look at a TFSP excavated in 2015. That summer, anomaly C5 was chosen for excavation based upon its magnetometry amplitude and morphology (Figure 1). Designated as Feature 261, its peak amplitude of 5.21 nanoteslas placed it just below the midpoint of all feature amplitudes in its testing block. After the removal of a 32 cm (12.6”) plow zone, the anomaly became visible as a dark circular stain on the floor of the unit. Since the stain was relatively large, measuring between 106 and 110 cm (41.7 and 43.3”) in diameter, the feature was bisected (cut in half) during excavation beginning with the west half (Figure 2). The prehistoric pit ended at 162 cm (63.7”) below ground surface where consolidated gravel was encountered. The volume of the TFSP can be calculated at 0.9 cubic meters, or in terms that may be more recognizable, nearly 32 cubic feet or about 238 liquid gallons. Suffice it to say that if you stood in the pit once it was completely excavated, you could just barely see out of the top of it (Figure 3). In total, fourteen 10 cm (3.9”) levels were removed from the west half, and five depositional horizons (identifiable dumping episodes) were removed from the east half (Figure 4).
Figure 3: Feature 261 after all pit contents have been removed.
Figure 4: Visible horizons along east profile of Feature 261 after west half has been removed.
The amount of cultural debris recovered through screening of pit contents is impressive. More than 13,460 items weighing more than 36.2 kilograms (or nearly 80 lbs) were catalogued from the pit. Essentially, the TFSP contains a variety of durable items that have survived placement in our acidic soils for approximately four centuries. Bone (40.5%) and flint (26.7%) dominate the debris by count, and as would be expected rock (53.8%) dominates the debris by weight.
Table 1. Counts, weights (in grams), and frequency of counts and weights for material recovered from Feature 261.
||% by Count
||% by Weight
The large amount of animal bone represents the end product of hunting, butchering, and cooking, and is typically dominated by the remains of deer, turkey, and turtle, but may also include elk and bear. The flint assemblage illustrates the various stages of knapping from cores to finished products such as arrow tips, knives, or drills. Because knapping produces a lot of waste (byproducts), more than 95% of the flint consists of flakes that were not further utilized. Much of the rock assemblage consists of burned limestone, the thermal rock of choice at Fort Ancient-age villages. It is likely that the more than 18.5 kilograms of burned rock contributed to the amplitude of the TFSP. Perhaps most impressive, nearly 1450 ceramic sherds were recovered. These represent breakage from cooking, overuse, and accidents. And, finally, nearly all of the shell assemblage consists of fragments of local bivalves that had been harvested for food. Only one freshwater bivalve had been worked; it had been drilled and used as a hafted digging hoe (Figure 5).
Figure 5: Representative artifacts from Feature 261. A and B, ceramic vessel rim sherds; C, drilled shell hoe; D, split bone awl (perforator); E, bifacial endscrapers; F, flint arrow tips; and G, flint drill.
Although the feature has not been directly dated, the presence of an animal/human ceramic applique, several rim sherds with lip impressions, and a pair of bifacial endscrapers clearly indicate that the TFSP is late Fort Ancient, or Madisonville-phase (ca. AD 1450-1625) in origin.