J5 loose materials

Loose materials in unit J5

September 2009 - James L. Walker

Synopsis

^a1	Early Dynastic III accumulations atop the outside (western most and southern most) stones of the first escarpment ^esc1 and floor f288. It is ashy and contains a lot of pottery. Presumably it results from the use of the f288 floor between the building of the two escarpments.	v217
^a2	Early Dynastic III accumulations atop deposit ^a1, and the inside stones of ^esc1. It is reddish and contains a layer (f278) of small pebbles and sherds. It may be the reminants of the seceond escarpment, ^esc2, or the result of its use and deterioration	v217
^a3	Naturally formed outside floors which were leveled and compacted to form the surface of the sacred plaza to the west of the late Mittani period western monumental staircase	v123
^a4	A series of natural accumulations which were deposited after the Mittani period ended. These are essentially abandonment accumulations.	v5
^a5	Naturally deposited surface loess which has supported plant growth and decay.	v1
Misc	Accumulations and lenses contained in baulks which were excavated as a unit, not stratigraphically.	v54

Discussion

Loose elements in J5 result from several sources. To the northeast, loess was deposited by wind and had its surface compacted by foot traffic or water. To the southeast, deposits often resulted from compacted loess being carried from the north by flowing water. These effects are most visible around the outside of the revetment wall systems. To the west, deposits at higher levels resulted from the deterioration of late Mittani mudbrick structures that were on low hills adjacent to the BA temple mound. Primarily in the vicinity of the revetment wall, isolated boulders were carried downhill by stormwater from construction on the temple mound and randonly deposited.

A. Natural Accumulations

The majority of the excavated features in J5 are naturally deposited layers, lenses, accumulations, and stones. Except for escarpments, glacis and one pavement, there were few man-made horizontal surfaces. The large stone installations (revetment walls and staircases) formed the barriers that contained these accumulations.

1. Accumulations above installations

Topsoil, a special type of weathered soil that supports plant growth covered the entire unexcavated surface of the unit. Directly below were two different types of accumulation. The first, which covered the installations in the northeast part of the unit were weathered loess, to a depth of about a meter. Having been deposited in the millenia after Mittani abondonment, they were relatively free of cultural material. The second, more prevalent along the southwestern perimeter of J5 were the detritus of deteriorated Mittani mudbrick structures which overlooked this area to the west and north. The accumulations f167 and the lower levels of f110 are examples. They consist of thin laminations which alternate between silt and sand.

2. Floating stones

Excavations (B2, B7) on the parts of the temple mound inside the revetment walls reveal that substantial stone structures had been built upon it in its early history. Prior to the Mittani period,these structures were abandoned and deteriorated. We assume that some of the stones used eventually were carried downhill by uncontrolled flowing water and randomly deposited along the revetment wall. They are isolated and not founded. Some examples include features f116 and f275.

3. Early accumulations

Use of the area at the base of the early revetment wall, ^wall2 during the Early Dynamic III period produced two accumulations. The first, ^a1 was deposited atop a stone floor, f288, probably prior to the construction of the baqaya escarpment. The second, ^a2 reflects use of that area to the end of EDIII. It is interesting to note that the next series of deposits did not occur until 1,000 years later during the early part of the Mittani period.

B. Altered Accumulations

Some of the natural accumulations in the Mittani period were altered by either the actions of flowing water or humans. Since the pre-EDIII temple mound and revetment wall were higher north of unit J5, water flowed north to south along the wall, being confined to a channel on the west by a structure yet to be excavated. The flowing water both eroded existing deposits and dropped new silt and sand in the channel.

1. West Plaza floors

When the late Mittani west monumental staircase was built, an accompanying sacred gathering area (plaza) was also constructed. Although there is no direct evidence as to how this was accomplished, the most likely method would have been to level the existing natural accumulation to the west of the staircase. Once formed the plaza would have been maintained by periodic leveling of new loess accumulations.

2. Water action

The relatively swift flow of water in the confined channel in the north part of the unit eroded existing floors and structures (e.g. f206 cut mud escarpment f74). It also deposited soil and cultural material along the south face of the revetment wall. The flow was sufficiently fast to erode EDIII deposits and trigger the need to construct a stone and sherd floor dated to the Mittani period to prevent the revetment wall from being undercut. (See v183.)