Friday, September 27, 2013

0207 – Ditches and palynology

Ditches are very interesting contexts for pollen analyses in Alentejo (a dry area, and therefore not very good for pollen preservation). Ditches can perverse humidity, helping the preservation of pollen.

In Perdigões, after a first study done by Jane Wheeler (Wheeler, 2010)  we applied for these analyses through the Portuguese Laboratory of Archaeosciences (LARC) that initiated a new program of scientific cooperation with the National Archaeological community in 2012. For that a specific project was elaborated: “Reconstitution of paleo-environments in Perdigões area.”

The collected samples in the excavations of 2012 were already processed and the results are in press in the journal Apontamentos de Arqueologia e Património that will be published next October 2013, being authors Randi Danielsen and Patrícia Marques Mendes.

Sampling in ditch 6

They refer to the Neolithic contexts of Perdigões and provide a quite relevant information about the landscape flora of the period in the surroundings of the site.

Diagram of results from Randi and Mendes, in press. 

In 2013 we continue to developed the project and new sampling was made, now integrating Chalcoltic contexts. We hope to get a good picture of the evolution of local landscape during the late fourth and 3rd millennium BC and provide empirical data that help in the interpretations of the human occupations and activities in this region.

2013 sampling in the Late Neolithic hypogeum structure

Bibliographic References:

Daneilsen, R. and Mendes, P.M. (in press), “Pollen analysis of Late Neolithic ditch deposits from the Perdigões archaeological site”, Apontamentos de Arqueologia e Património, ), Lisboa, NIA.ERA, p.13-20.

Wheeler, Jane (2010), "Paleoenvironmental assessment of two archaeological sediments from Perdigões, Alentejo region, Portugal", Apontamentos de Arqueologia e Património, 6, Lisboa, NIA-ERA Arqueologia, p.41-45.

Wednesday, September 25, 2013

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.

Tuesday, September 24, 2013

0205 - Ditched enclosures and carved rocks

It is an interesting relation, although difficult to establish, that seems to be emerging in some sites.

In Moreiros 2, several rocks with cup marks were identified the periphery of the enclosures.

Carved rocks with cup marks in the periphery of Moreiros 2 enclosure (images taken from Valera, Becker and Boaventura, (in press) "Moreiros 2 (Arronches, Portalegre). Geophysics and chronology of the internal enclosures"

At Torrão a rock also with cup marks is known near the enclosure and in Perdigões there is a rock inside the Chalcolithic enclosure, but outside of the Neolithic ones almost totally carved with cup marks, also present at one of the stones of the cromlech.

Carved rock with cup marks at Perdigões.

Of course we do not know the exact chronology of the cup marks, but in these three situations they are in the periphery of Late Neolithic ditched enclosures. What they mean we do not know. We can only speculate and many ideas were put forward. But maybe there is a relation between them and the practices that were taking place inside the enclosures.  

Thursday, September 19, 2013

0204 – Something different (but...)

Today’s post is not about Neolithc or Chalcolithic enclosures, but about another kind of enclosure and from a different chronology. It is about an Iron Age funerary ditched enclosure that is being excavated by Omniknos Company (direction of Tiago do Pereiro) near Beja.

This is a rectangular enclosure defined by a ditch about 1 meter wide, with a central rectangular grave inside. What is interesting is that the ditch shows several recuts. In one of them a human skeleton was recorded. It is possible that there are more, for the majority of the ditch is still to be excavated.

The larger rectangular enclosure with the central grave (the grave in the ditch is being excavated)

In one side, the rectangular ditch is partially overlapped by another ditch that seems to be part of another rectangular enclosure, but not totally finished and with some intervals in the sides, as if the rectangular enclosure was built in an additive way. It also has a central rectangular grave and a human skull just started to appear in the corresponding ditch. It seems that there is a central grave surrounded by graves in the enclosing rectangular ditches.

The other enclosure overlapping the large one.

Some similar contexts from Iron Age were excavated in Alentejo in the recent past: Vinha das Caliças (by Arqueohoje Company) and Poço das Gontinhas (by Era Arqueologia Company).

Of course we are in presence of a different cultural and historical context, but it did remind me of Bela Vista 5, a ditched enclosure from late 3rd millennium with a grave surrounded by two ditches, being the outside ditch built by segments and showing recuts (although no human remains were found in the small excavated areas).

In fact, these funerary monuments seem to present a sequence of use and construction until they get their final shape. A bit like the Bronze Age cist graveyards that grow from a previous central grave. And the same process of “construction in use” before reaching the final form was also documented for megalithic monuments in Galiza.

We tend to focus in what we see and tend to forget that we see final stages. Things have often quite complex biographies and that later look might result of a process of “construction in use” or “by use”, and not done at once. But they present a pattern. Which means that there are prescriptions and intentions that are followed, resulting in the final significant designs. We see that in several prehistorical ditched enclosures

Although from different times and cultures, there are human behaviors that respond to similar social needs or involve similar social problems. 

Monday, September 16, 2013

0203 - Pé da Erra ditched enclosure

Ditch section of Pé da Erra, showing a clear recut.

An old site has revealed itself as a ditched enclosure in recent excavation of the UNIARCH team. It is Pé da Erra, near Coruche, known since the seventies of the last century. We still do not have specific information about the new findings. But the simple fact that there is a ditch enclosure is significant, because this is a peripheral area to the actual concentration of ditched enclosure in Alentejo’s hinterland. It is a confirmation of what I argued some time ago, that this kind of contexts would start to appear in other areas of the country (in this case in the Sorraia valley, a tributary of the Tagus river), even if they don´t show the same concentration of sites. Things appear when the times are ready for them.

Information and picture taken from here

Friday, September 13, 2013

0202 - New enclosures under excavation (2)

The internal enclosure of the new site near Santa Vitória (Beja). Photo from Rui Ramos.

Thursday, September 12, 2013

0201 – New enclosures under excavation (1)

A new ditched enclosure is being excavated in Alentejo, near Santa Vitória (Beja), by the company Omniknos, directed by Rui Ramos..

At least four sections of ditches will be cut by a water pipeline, possibly corresponding to three different structures. They are being defined and one of them is clearly sinuous, adding another site to the already long list of Portuguese ditched enclosures with sinuous ditches.

By the material associated, they must be from the 3rd millennium BC, but one of the ditches is cut by a Bronze Age cist. Believing the locals, a necropolis of cists in this area has been destroyed over time by farmers.

To Southeast, maybe 300/400 meters there is a funerary Chalcolithic hypogeum, where three pits are connected by internal passages. Between the hypogeum and the enclosures there are some pits, some of them from Bronze Age.

This is a quite interesting new site.

Sunday, September 8, 2013

0200 - Papers on ditched enclosures

In the next six months several papers of mine (some in collaboration) regarding Portuguese ditched enclosures, at present in press or being finished, will be published. Here are the references:

A. Valera (2013), “Breve apontamento sobre a dimensão cosmogónica dos recintos de fossos da Pré-História Recente no Interior Alentejano”, Cadernos do Endovélico, Nº1.

A. Valera (2013), “Recintos de fossos da Pré-História Recente em Portugal: investigação, discursos, salvaguarda e divulgação”. Almadan. 18.

A. Valera (2013), “Cronologia dos recintos de fossos da Pré--História Recente em território português”, Actas do 1º Congressos da Associação dos Arqueólogos Portugueses.

A. Valera, (2013) “Cronologia absoluta dos fossos 1 e 2 do Porto Torrão e o problema da datação de estruturas negativas “tipo fosso”. Apontamentos de Arqueologia e Património. 9.

A. Valera, H. Becker, R. Boaventura (2013), Moreiros 2 (Arronches, Portalegre): geofísica e cronologia dos recintos interiores. Apontamentos de Arqueologia e Património, 9.

A. Valera; T. do Pereiro (2013) “Novos recintos de fossos no sul de Portugal: o Google Earth como ferramenta de prospecção sistemática.”, Actas do 1º Congressos da Associação dos Arqueólogos Portugueses

A. Valera, V. Filipe, N. Cabaço (2013). “O recinto de fosso do Outeiro Alto 2 (Brinches, Serpa). Apontamentos de Arqueologia e Património. 9.

A. Valera; A.M. Silva; J.E. Márquez Romero (2014) “The temporality of Perdigões enclosures: absolute chronology of structures and social practices”, SPAL.