Subsurface Survey in Wadi Ziqlab


The text of the preliminary report on the 1992 survey follows.

Methods of the Sub-surface Survey, 1986-1992

It is conventional wisdom among archaeologists that if there is a site present, some material from it will show up on the surface. Routinely we base appraisals of ancient village sites on this principle and we even derive population estimates from evidence which is found on the surface of sites that have tens of meters of desposit (Hole 1979: 208).

Unfortunately, for some kinds of sites, such as the camps of mobile pastoralists and many kinds of agricultural installations, the conventional wisdom is in error. "The chief problem is that ancient remains of this kind are likely to have been robbed of their stones or buried under later deposition, and thus they may not be obvious on the surface" (Hole 1979: 208). In addition, various geological processes can increase the surface visibility of some sites while deeply burying others to make them virtually undetectable.

As a response to the problem of poor site visibility in parts of Wadi Ziqlab subject to colluvial deposition, in 1986, 1987, 1990, and 1992, we augmented the 1981 survey by walking along wadi channels and road cuts - this was mainly the work of John Field, the project geologist - and by beginning a systematic program of sub-surface testing.


Sub-surface soundings in Wudyan Aqaba and Sofâr

Sub-surface survey in Wadi Ziqlab took place during each of the four excavation seasons. It began on an extremely modest scale in 1986 when we were able to spare two team members for a few days to excavate a single 3-m x 1-m trench (WZ 115) within the confluence of wudyan 'Ain Sirin and Sofâr. We chose this location because it lay near a former spring, at the confluence of what once had been streams, and in one of several locations along Wadi Ziqlab that modern tent-dwellers favour for their good drainage, access to water and shelter from wind and sun. In fact, our first choice was the terrace immediately to the west, but it was occupied at the time by two tents with their families and an extremely vicious dog. In retrospect, it seems that we did not dig this first trench nearly deep enough, abandonning it when we reached what appeared to be sterile subsoil but which more recent evidence suggests could well have been fairly recent alluvium. In 1987 we excavated another 1 x 3 trench in the adjacent stream terrace, now unoccupied, and quickly began to discover subsurface microliths, sickle blades and other tools. We then supplemented this test trench, Area A at WZ 200, with a 1.25-m x 1.25-m "phone booth" called Area B, and expanded the Area A trench laterally to expose what we would later identify as a Late Neolithic cist grave. Already by this time we were sharing the site with another family of tent-dwellers.

Following the success of our 1987 discovery, we were able to devote a greater proportion of our resources to sub-surface testing in 1990. By this time we had identified all of the stream terraces that lay within a few kilometres of WZ 200, both upstream and downstream, and that were neither too tiny nor too steep to have been reasonable locations for settlement. Many of these locations, like the ones tested in 1986 and 1987, were near current or former springs and many are favourite campsites for modern tent-dwellers and their livestock (figs. xxx). Since our goals now included finding sites that could be associated with wite WZ 200, and not merely a representative sample of any sites, we decided to investigate these terraces, systematically, by placing one or two 1 x 3 trenches in each, only the larger terraces being subject to two trenches. In addition we excavated one such trench (Area 1R) at the front of the rockshelter across the road from WZ 200, but all of the nicely stratified hearths and other deposits in it are modern.

A team normally consisting of two staff members and four or five local labourers excavated these test trenches. The localities of the trenches were given site numbers in the 300 series to distinguish them readily and to emphasize that they were not necessarily the sites of ancient cultural activity. Where possible these trenches were dug to a depth of 2 m. Seven (WZ 300-306) were placed in different terraces for a 2-km stretch to the south of Tabaqat al-Buma, in a segment of Wâdî Summayl which the locals call variously Wâdî Sofâr or Wâdî Sokâr. Three (WZ 307 A and B, WZ 308) were placed near one of the main springs of `Ayûn Ziqlâb, called `Ayn al-Hammâm, just prior to the spring's deep burial by new road construction. Two trenches (WZ310, Areas A and B) were next to a road cut some 400 m northwest of Tabaqat al-Buma, along the stretch of the Ziqlâb drainage called Wâdî Aqaba. The results of these test excavations appear below.

During 1992 we continued the programme of sub-surface testing, this time continuing the systematic examination downstream to the west and upstream along Wadi 'Ain Sirin.

So far the program of sinking narrow trenches, in a sample of natural terraces that are today the prefered locations for modern tent sites, has yielded several additional sites, including WZ 200, or Tabaqat al-Buma. These sites are not part of the statistical sample that is the basis for studying changes in settlement, and ultimately will be part of a new sample of the population of wadi terraces.

1992 Report on Subsurface Survey in Wadi Ziqlab

Because the Neolithic occupation of site WZ 200 turned out to be more extensive than we had anticipated, in 1992 we only conducted subsurface soundings at three locations along 'Ayun Ziqlab as well as three more on the peripheries of site WZ 200 itself. As in 1990, off-site soundings were numbered in the 300-series to make them easily distinguishable from sites where cultural material was known to occur, and those that are not clearly sites of ancient human occupation or activity are termed "localities."
The first of these, WZ 311, was placed on a scarp near the road about 100 m northwest of WZ 200, where the project geologist had notice some possibly Upper Paleolithic artifacts in an old colluvium. Although the locality did produce some lithics, this sounding was closed after a few days when it became clear that the artifacts had probably been transported from some place farther upslope.

Locality WZ 312 was placed in a terrace opposite site WZ 310. Even on the surface here we were able to find quite a few chert cores, and the sounding indeed yielded 116 sherds, most probably of Roman or Byzantine age and showing signs of rolling, as well as fairly large numbers of lithics, particularly cores. Again it was fairly clear that this material had been transported from upslope - indeed we would expect cores to roll downhill more easily than would flakes - and we sought a source for this material by placing an additional sounding much farther upslope.
We departed from our planned program of soundings by placing a probe, locality WZ 313, well above WZ 312 in an attempt to discover the source of the lithics that we had been finding in the latter locality. It did not turn out to be an undisturbed, primary deposit of prehistoric material culture either. Although there were many lithics here, they were mixed with 19 sherds, again mainly of Byzantine age.

An unexpected bonus of the work at locality 313, however, was the discovery of a likely source for most of the lithic raw material used at site WZ 200. A brecchia that occurs just uphill from (south of) the locality is rich in flint nodules, many of which have the same colour and texture as flint used at Tabaqat al-Bûma during the Neolithic. It is likely that this wealth of flint of relativly high quality is not only responsible for the abundance of cores downslope from the brecchia, but that this was a source of raw material that WZ 200's Neolithic inhabitants knew well. In future we will attempt to characterize or "fingerprint" these flints by their trace elements and microfossils to see if they are indeed the ones most likely used at WZ 200.
At the same time our excavations of Kebaran deposits at site Tabaqat al-Bûma were indicating that the artifacts were oriented randomly within a colluvium and had probably been transported there along with the soil. Consequently, we also placed some test trenches on the slope above the site, where there were small terraces, to see if we could find the source of this material.

Area C was the first of these trenches above site WZ 200. It was located on the top of a prominent knoll in the slope, where the surface was flat enough to be a possible habitation place. It produced almost no cultural material and we hit bedrock only a few centimetres below the modern surface.
Area D was located farther downslope, where a shelf in the bedrock provided an opportunity for soil to collect and where there seemed to be some possibility of a rockshelter. It also produced very little cultural material and bedrock appeared only a short distance below the surface, in spite of the organic-rich soil found here that seemed likely to be cultural in origin.
Around site WZ 200, we also cut back a natural scarp north of the site below the rockshelter (Area 2R) where the project geologist had noted some mud brick and a possible hearth. The depth of the mud brick below the modern surface suggested the possibility that it was ancient, but work in Area 2R soon indicated that was modern, although its deposits still proved interesting. Barbed wire was found next to the section through a low mud-brick wall, and this wall soon proved to be the western boundary of a large trench that had been filled with silt during several episodes of flooding. Informants from Tubna told us that this large trench, along with a whole camp, had been destroyed and buried during a major flood of 1975. Some 2 m of deposit above the trench had apparently slumped down in a landslide during this flood, burying this part of the camp quite deeply in a very short time. Although these events are very recent, they are instructive in that they indicate one way in which some of the ancient and prehistoric sites in the valley bottom could have been buried well beyond the reach of most archaeological surveys. The possible hearth or pit filled with stone and ash occurred in a location that is stratigraphically well below the mud brick and the buried trench, and it is indeed possible that it is prehistoric. Since we found no artifacts associated with it in the very small volume of soil we removed in cleaning back the scarp, we are undable to date it at present, but we hope to have a radiocarbon date for it in future.