0402 - Santa Vitória: the usual

The work in Santa Vitória has been mainly cleaning. Namely the already excavated ditches, from which there is no new information to collect. 

But in ditch 2 we started to define a new section and the top of preserved fillings, and the expected is there. Like in many other ditches of many other enclosures, Santa Vitória is also presenting recutings filled with layers of stones.

0309 – Back to Perdigões

Next week I will be back to Perdigões to finish the section in ditch 7. In this section the ditch is already 3 meters deep and, although it is quite narrow down there, the walls are still quite vertical. So it is not easy to estimate how much deeper it will go.

Note that the section is in the area where ditch 7 is starting to overlap ditch 8 (a previous Neolithic one). So the inner wall of the ditch (right in the image) is, in this area, constituted by the sediments that were filling the previous ditch. This filling, that goes until about 2 meters deep (ditch 8 was less deep), is constituted by deposits of earth with faunal remains and pottery shards. But this wall of earth was not eroded and it would have been easily if exposed to winter rains. This means that ditch 7, at least in this section, had to have been opened and rapidly filled.

And as you can see in the section, after it was filled (with a sequence of layers of stones, faunal – and human – remains and pottery shards) it was reopened through a recutting, then filled with layers of stones.

This is a stratigraphic sequence of openings and deliberate fillings that shows the nature of this ditch. A ditch that defines a inner enclosure that I now think that can be related to a later, complex and highly symbolic occupation of the central area of the natural theatre where Perdigões stands.

0255 - Evaluating the effort 3

Prehistoric ditch in Avebury (UK)

Evaluating the effort of digging ditches and of building ditched enclosures is not just a question of measure the amount of rock and earth excavated and moved. That is just part of the equation. Other important parts are the number of people involved and the duration of the building activities. As noticed by me and others, great building enterprises are available to small communities if they are done by stages in time and if they can congregate the will of the community. And it is in that will that I want to focus today.

Functionalist approaches naturally focus on function. No problem with that. The thing is that they focus in the function of the structure once it is built, and pay no attention to the function of the building process, which is an important social one.

For some decades now, some have argued for the need to focus on the social importance of the act of building. An act that goes much further than the pretended function of the feature itself. We have innumerous examples from all over the world and from different historical periods. Let me just give one example that I think is known to everyone: when Amish are reunited to build a barn for one member of the community, they are not simply building a barn to perform the function of storing the crops. They are doing something that touches deeply the identity of the community and reinforces their world vision, their social, political and religious bonds. As Marcel Mauss reminds us in his essay about the gift in polonaise societies, this facts that we study (in this case building activities) “are all total social facts, for they put in movement the totality of the society and its institutions or just an enormous number of those institutions, in particular when interactions were related to individuals. All these phenomena are simultaneously juridical, economical, religious, esthetical, morphological, etc.”

That is why some decades ago Evens argued that the process of building an enclosure had its main focus on the build process. For a functionalist mind focus on the subsequent utility of the thing, this might be hard to understand. But in many societies, inclusive in ours, many creations culminates in the very act of creation. Christ, we are leaving the times of the ephemeral.

And yet, it seems so difficult for some, today, to conceive that huge building enterprises might have had their basic motivations in the very act of building, in an ephemeral use and in the subsequent condemnation and in its social and ideological implications.

To evaluate the effort of building ditched enclosures in Prehistory it is important to go further than impressive metrics and politics of coercion.

0253 – Evaluating the effort 2

At Perdigões we have recorded 12 ditches. Seven of them were already surveyed in a section. Of course that we do not know if the dimensions of those sections “speak” for the entire perimeter of the ditches. We have evidence from other sites that a ditch volume and shape may change a lot along its perimeter. And Perdigões is not an exception. Ditch 12, the only one surveyed in two different areas, has a different shape and a different filling in survey 1 of Sector Q and in survey 2 of the same sector.

That shows us that we cannot generalize to a whole ditch what we observe in one section. But does not imply that, in general terms, we cannot try to approach the general picture.

For instance, Dicth 1 at Perdigões is a long one: it has a perimeter of almost 1,5 km. It was surveyed in a section near Gate 1, first by the ERA team and in the last few years by University of Málaga team (that is collaboration in the General Program of Research of Perdigões). It showed a “V” shape, with about 3 m deep and 7 to 9 meters wide. It allow us to calculate a volume for a one meter section: 9.61 m3. Multiplying this volume by the perimeter we get a volume of 14232 m3 and using the pattern wait of a m3 of diorite (around 2600 Kg) we have 37 000 tons of rock extracted, just for Ditch 1.

This can gives us an idea of the amount of work involved in Perdigões through its living time. And more interesting: once again, where is that amount of bedrock?

Ah! And do not forget that we have evidences of practices of re-cutting of some ditches after their first filling process. And that enlarges the amount of work that we can calculate to the recorded structures.

These big enclosures were huge public enterprises.

0252 - Evaluating the effort 1

Outeiro Alto 2 is a small ditched enclosure. It has just one ditch with a perimeter of 101m. If the size of the ditch is regular (as the two opposite surveys suggest) it will have a volume of 254 m3, corresponding to 406 tons of extracted rock (1600kg per 1m3, as average for limestone rock). That rock is not in the site: not outside the ditch and not inside the ditch (as it would be expected if there was a bank built with the extracted material). This is a common situation in Portuguese Ditched Enclosures, big or small.

0206 – Debating ditch fillings and ditch excavations.

Interpretation of ditch functions depends a great deal on what we find inside them. And what we find inside them depends a great deal on the way we excavate them.

Ditch 8 of Perdigões is a good example of these two circumstances.

First let’s look to what we find inside the ditch. The top of the ditch filling was exposed in a 12m area. It showed a deposit covered by a central concentration of fragments of pottery. Removed that first layer of pottery another one appeared. Just like ditch 12, Late Neolithic ditch 8 had its top filling layers incorporating an “avenue” of pottery shards (Figure 1).

Deposition of pottery shards in the top of ditch 8 of Perdigões (taken from the report of 2013 excavations)

But the section that we have done in the ditch showed that this horizontal depositions of pottery, stones and faunal remains continue in depth. If we look to the plans of this section (figure 2) we will see that there are layers of depositions of those material intermediating with layers of just earth, until the bottom part of the ditch, where this kind of depositions became continuous.

Plans of the stratigraphy f the section excavated in ditch 8 (taken from 2013 report)

So, ditch 8 was filled with layers of intentional horizontal depositions of selected materials (fragments of pottery, faunal remains and stones), in an intermittent rhythm. This stratigraphy is not coherent with draining or defensive functions. It clearly shows that there was an intentional filling that went on in an intermittent rhythm, providing horizontal layers. The intermittence suggest that these practices of intentional deposition were intermittent themselves. That they were periodical.

The sections of a 1,5m deep ditch and the definition of the top layers of pottery depositions took us two campaigns (one month each) to achieve.

The second issue that I want to address is: why this kind of depositions are not occurring in other ditch enclosures excavated in Portugal? Are they a particularity of Perdigões? Perhaps they are. But one thing I am convinced: the actual practices of excavations in rescue archaeology would not be able to detect these depositions. When you have to excavate a ditch and get paid 55€ a square meter (independently of the depth), then you have to be satisfied if a rough image of the stratigraphy is obtained. Archaeology of negative structures is progressively becoming the activity of quickly emptying pits and ditches.

So what empirical record will we have to deal with in our debates, theoretical hypothesis and social-historical problems? What is being rescued? Does it worth what it costs?  

The problematic of ditch enclosures is not just about understanding Prehistoric communities. Is also about understanding our own society, and why we do what we do.

0127 - Bit by bit

This is the way the outside ditch of Bela Vista 5 was done. Not at once, but by a sequence of short ditches, that were overlapped and are different in depth and thickness, as we can see from the different profiles obtained in several areas (an image from the archaeological report in preparation) and from the distribution of stone concentration in the surface of the sequence.

In some of them we can see evidences of re-cutting.

 

Naturally this delimitation has no functionality for defence or water circulation or other more practical goal. The sections were made to be filled (and some were filled before the next section was opened). And they are filled with stones and pottery shards: no faunal or human remains, no stone tools, no loom waits were recovered in the surveyed areas of this “ditch”. Just pottery, showing a clear selection of a particular category of material.

Faunal remains appear in some of the inside pits. The inside small ditch, on the contrary has some faunal remains associated to the pottery shards, and enclosures an area with just a pit grave. All the data from this enclosure points to a place of highly ritualized practices.

After the report is complete we intend to publish a monographic paper on this important site.

0110 - Overlapping ditches

This is an important issue for ditched enclosures understanding that hasn’t been researched as it deserves in Iberia. Here is a situation from Perdigões that we just started to approach.

 In sector P we open an area to research the overlapping of ditches 7 and 8. The first observation is that, contrary to what we assumed by the geophysics magnetogram, ditch 8 is older than ditch 7. In fact, it is ditch 7 that cuts ditch 8, and partially “walks over it” in the excavated section.

 

 

And that is really odd. Why open a ditch (which implies a lot of work and effort) in the bed rock, and then cut just partially, in small distances, a previous ditch? Why not use more of that previous ditch?  Or, why not fully avoid that previous ditch?

It seems that they just wanted to cut a new ditch, with a wavy plan, with no regard to previous ditch 8. But, if we look to the magnetogram, ditch 8 is a concentric mach to previous ditch 6. And why the ditch has part f its trajectory inside ditch 7, and then sudden  get outside, and then curved to be over it, just to get in again?

The conclusion is that no easy modern rational explanation can deal with these strange practices of opening ditches at Perdigões. We must keep our minds opened in the presence of these enclosed spaces.  The previous seems to condition the posterior, but in very complex ways not easy to explain.

0097 - How did they do it?

They did choose adequate bedrocks. There is a clear relation between Portuguese ditched enclosures and geology that enables an easier excavation. But making it easier doesn’t mean it was easy.

In fact, to excavate the ditches, that in South Portugal started at least in Late Neolithic (second half of the 4th millennium), they must have used the technology developed since earlier times: the technology developed in mining for flint or for minerals, like variscite.

I have already drawn the attention for the fact that there are several evidences of “transference of technology” in Prehistory, from some areas to others; from some kind of architectures to others. For instance, the building of the access corridor between walls to the inside enclosure of Castro de Santiago is clearly an application of megalithic building procedures.

So, to study the technologies adopted to open ditches it is in mining tools and in mining techniques that we might find a window. There is a clear interesting relation that can be established between the researches of these two Neolithic practices.

And the same can be argued about the hypogeal building tradition. There is knowledge and an assemblage of techniques and tools that must have had a transversal use in different building activities. Underground techniques of excavation are certainly earlier than ditched enclosures in western Iberia. They might have provided the means to the architectural materialization of some new ideas. Just like the megalithic “engineering” was certainly helpful for walled enclosures.

So, looking into mines, and mining material, might be useful when we study ditched enclosures.

0094 – The irregularity of ditches.

The inner ditch of the enclosure in excavation process: 1,5m deep in first plan survey (back of the dich); 1,3m deep in the next one; 0,8 at the gate. Notice the presence of a layer of geological material at middle depth.

The irregularity of ditches, not in plan, but in depth, is another issue that is very important to question functionality and meaning.

It is expectable that a ditch to accomplish the function of defence or infrastructure of a palisade presents a general regularity in terms of depth. The problem is that for almost all Portuguese ditched enclosures only small parts of ditches were surveyed. But recently to exceptions to this “rule” allow treating this problem.

At Senhora da Alegria, a small enclosure (about 10 meters diameter) at the top of the site presented a circular plan with one gate and only a pit inside. The pit had inside large fragments of burned wood and the ditch revealed a interesting depth profile: it grows deeper from the back towards the gate, with a significant slide percentage.

At the enclosure in process of excavation in Alentejo the inside ditch presents a similar size and also just one gate. But the depth of the ditch reveals the opposite behaviour: it grows deeper from the gate sides to the back: 0.8 / 0.4 at both sides of the gate and 1,5 at the back of the circle. So it presents also a significant slide. Inside, also just one pit, still in excavation (sealed with stones and with complete pots underneath).

What the strange behaviour of the depth of these ditches suggests is that they cannot be associated to any kind of palisade or regular barrier: were they built to be walked inside, from the surface to a deeper area? It has something to do with water circulation and accumulation in a specific area of the ditch? I recall that at least one of the ditches of the enclosure of Águas Frias the structure also ended in a sort of ramp. Let us see what this new enclosure has to reveal in the next days. For the moment the fillings of the ditches are as heterogeneous as their depths.

The back of the ditch: note the absence of geological material layer just one meter away from the other profile.

0083 - Cutting and re-cutting

Some ditches present evidences of re-cutting. When a previous and larger ditch is totally or partially filled, sometimes another smaller ditch is dug in those deposits. Usually, this is not a total reopening of the first ditch, but simple of a small part. That is the case recently detected at Senhora da Alegria, in a ditch belonging to the Late Neolithic phase.

This means that we cannot look at this reopening as a “maintenance task”, but rather as a new use (even if with similar purposes) of a previous perceived structure. And the argument of saving efforts, by excavating deposits rather than bedrock, is not always an argument. At Senhora da Alegria all ditches are excavated in deposits, being of previous occupations or of weathered sandstones. So, no big difference can be assumed in terms of work invested. So why are there, in the more than a dozen ditches already identified, situations like new ditches using part of previous similar structures?; situations that new ditches are open quite near to others without reopening them?; situations where a new smaller ditch is totally dug inside another?

The answers can be different for all situations and probably related to several dimensions of a living site: changes in space organization; changes in the occupied area; consequences of a seasonal occupation, etc. But what I want to argue is that the reopening of a previous ditch that is filled with stones and archaeological material is not just an economic strategy of those communities or an activity that brings troubles to the archaeologists (because changes and mixes older materials with recent ones): it is an intervention that is strongly conditioned by the earlier structure, in physical terms, but also in meaningful ones. It is a moment when a given community interacts with previous construction and previous materials. What would they think when they dug previous artefacts? Would they just have a “catchment attitude”? Or were those materials seen as a link to ancestors? How would a segment point or an early arrowhead be seen by a person that produces more recent bifacial and all retouched arrowheads? Or a decorated shard in a moment where all pottery was undecorated?

Digging a ditch in previous structures is different from digging a ditch in the bedrock. That is certain, but not only because of the labour involved or because of a similar space organization. It has consequences in other dimensions that are important to understand past decisions and their outcomes.