The Grammar of the Archaeological Record

14 Deposition

Giorgio Buccellati – August 2009

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14.1: Concepts

Deposition (or depositional process) is the way in which things got where they are in the ground, and depositional history is the construct that describes that process. It is not observable in and of itself, but is rather based on inference from observations of emplacement. These inferences bear directly on chronology and function.

The classification of features according to depositional categories depends essentially on the manner in which the process can be inferred to have happened, i.e., on the manner of origin of the emplacement. There are two distinct manners, corresponding in part to the observations pertaining to emplacement:

  1. Ordered aggregation reflects an intentional approach to construction, whereby elements receive their coherence from a specific and planned building process. Similarly intentional is a planned discard process whereby masses of material are released into otherwise empty spaces.
  2. The other two types of emplacement elements reflect instead an unintended accretional development and a disaggreagtional process whereby components come to be laid down through accidental human activity or through natural causes.

The major types are shown in tabular form in the following chart (for the typological definition, see under typology):

criterion: manner of process example
intentional construction building process resulting in the coherent organization of surfaces and volumes pavement, wall
discard generally planned release of a mass fill, dump
unintentional accretion gradual and unintended buildup accumulation
disaggregation (generally unintended) collapse, gradual erosion brickfall

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14.2: Correlations between emplacement and deposition – and typology

To be sure, the categories that define emplacement and deposition are closely interrelated, just as they are in turn with typology. Ultimately, it is the typological definition that we use currently – a definition that is discussed under typology. But it is important to keep the various levels of analysis distinct, and to have the conceptual tools for doing so. This is the goal we pursue within the framework of the Urkesh Global Record (UGR).

It may be useful to show here in tabular form the correlation between emplacement and depositional categories:

emplacement deposition example (typological definition)
horizontal surface construction pavement
layering or gradual build-up accretion accumulation
amorphous amassment discard and disaggregation fill
ordered aggregation construction wall

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14.3: Depositional history

I use the term “deposition” in a narrow sense to refer to whatever has come to be embedded in an all-enveloping matrix. Thus, even construction, which would not appear to be depositional in the proper sense of being “deposited,” is subsumed under this concept in a context like ours, where nothing is visible above ground before the start of excavations. As a result, “depositional history” refers not only to accumulations and fills, but also to the way in which buildings developed over time as they underwent structural changes

Once exposed, buildings may be analyzed more specifically in terms of their constructional development, and this may more properly be treated separately.

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14.4: Constructional history

I use the adjective “constructional” partly to stress the parallel with the adjective “depositional” and partly to stress the difference with respect to “construction history.” The latter may be reserved to refer the history of a particular building, while “constructional” may be taken to refer to the method of analysis whereby one can discover an inner stratigraphic history declared by the way in which the structural components are juxtaposed in space.

The simplest observation in this regard pertains to the sequence in which the components must have been set in place: obviously, the laying of foundations precedes the erection of a wall.

Other cases present a more nuanced situation. If the lower part of a brick wall is made of different bricks than the upper part, is it because the supply of a certain type was exhausted, or because at some point the roof was removed and the walls were raised to support a new roof? (The latter is the case with the walls of the palace walls, which will be presented in detail in book AP.)

Another important example pertains to the ābi and will eventually be treated in detail in book A12. Here we can (a) detect a marked difference between the lower and the upper courses of stones, and (b) infer that an earlier cylinder was broken make room for the antechamber (an observation first made by Claudia Wettstein).
     Yet another example of constructional history pertains to book JP, where the disassemblnig of the eastern staircase may be linked with the reorganization of the space in function of a wider cavea.

In all of these cases, we can assume temporal succession, but obviously the moments of this succession appear to have different weight depending on other concomitant considerations. We can link these more significant “moments” to strata by correlating the structural observations to other depositional factors.

This approach, which has always been central to archaeology, has been developed more fully in what has become an independent discipline, which may be called the developmental analysis of buildings.

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14.5: Deposition vs. construction

There are two important reasons for subsuming constructional under depositional history:

  1. The first is that, in the case of an excavation like ours where nothing shows above ground, the building to be analyzed has been extricated from its matrix in function of a given strategy of excavation that presupposed specific depositional processes and functional uses. This means that the building as exposed has emerged from the ground in a manner that is conditional to the excavator's understanding of the those processes and those uses. As a result it cannot be described apart from that understanding, which is precisely the goal of depositinoal history to explicate.
  2. The second reason is that in most cases the building as exposed was never seen as such in antiquity. In other words, any structural coherence to what we see as exposed is filtered through a number of lenses that we cannot ignore. This is true, for instance, of both the ābi and the monumental Temple complex, where distinct chronological horizons are visible today in ways that never were in antiquity. Here, too, it is indispensable to retain a tight link to the excavator's understanding of depositional history.

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14.6: Constructional history and typology

Generally, constructional history pertains to structures for which a typological coherence has been established, or at least proposed. To that extent, a full argument in this respect can properly be proposed, in most cases, only after a typological analysis had been developed. For instance, in a discussion of the construcional history of the Palace we must first define what, in our judgement, makes the Palace a coherent typological unit, where all its elements may be assumed to have been a congruent whole at any given moment in time. For an example, see the treatment of the stone pavement of the courtyard in A16.

There is obviously a give and take among all these elements, but what is especially important is to keep gthe levels of analysis distinct, even when they intersect.

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14.7: “Harris matrix” and depositional synopsis

The so-called “Harris matrix” is widely used to chart stratigraphic sequences. Undoubtedly a most useful tool, I feel that its nature is often not properly understood, and that its effective range is limited. As an important complementary tool, I propose a depositional index and synopsis, as alternative way to chart the depositional process [missing link, ZGy27 mDP].

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