Tuesday, May 31, 2011

0018 - Filling ditches

Ditch 3 at Perdigões set of enclosures

One of the main questions on ditched enclosures is the nature of the filling processes of the ditches. Natural courses, usually surface erosion; human activity associated to discarded rubbish; human activity related to structured and meaningful depositions. These are the most debated origins to explain the deposits inside ditches. But, once again, theoretical debate and empirical evidence kept missing each other, resulting in axiomatic disputes.

In Perdigões enclosure, ideas are being tested. Different ones. Competing ones. Ideas that may be conciliated. Ideas that cannot.

Regarding the filling processes, the wavy ditch 3 revealed an interesting situation (Valera, 2008). A first dynamic of clear human origin, characterized by horizontal depositions of layers of stones, pottery shards and faunal remains (also with some human remains) was in course until the middle filling of the ditch. This process was dated by radiocarbon from the first half of the 3rd millennium, with equal dates from the bottom and the top of this first sequence, suggesting a relatively "rapid" filling (Valera & Silva, 2011).

Then, an episode of hydro erosion occurs inside the ditch, excavating a canal and generating sedimentation of silt layers, with little archaeological material.

Section of Ditch 3 and calibrated radiocarbon dates (two sigma)

The filling of the upper half of the ditch corresponded to a different dynamic. Structured depositions of human origin continued, but were much more restricted and of different nature. The archaeological material is now of smaller size and more disperse. Stones are rare. And the radiocarbon date for the beginning of this phase points to the middle of the millennia, statistically representing a latter moment.

The sequence was also independently detectable in the faunal analysis (Costa, in print), confirming the stratigraphic observations and radiocarbon dates.

So, we can conclude:

a)The ditch had a initial phase of filling where human horizontal and structure depositions took place, choosing particular elements: stones, pottery shards and faunal remains (with some human bones also);

b)This process, apparently rapid, stopped at middle ditch depth, and a hydro erosion process dug a small canal on the surface of the filling deposits.

c)After some time (which means the ditch half full was open for some time) a new process of filling begun, with different characteristics, where human and natural processes seem to conjugate.

d)No evidence of bank erosion was detected inside the ditch, and another one (Ditch 4) was excavated just 2,5 m distance by the inside. Radiocarbon dating shows that this opening was contemporary of the 2nd phase of the filling of Ditch 3, that definitively didn´t have an associated bank.

This process reveals that there is a decisive human intervention on the filling that, at list in the first phase, is much more important than natural processes. It also shows that the association of ditches with banks must be demonstrate and not simply presumed. Finally, it demands theoretical explanation of the nature of the human depositions, also empirically tested in honest ways and not axiomatically (or devotedly) assumed.

Why was this ditch opened and filled partially with selected materials that don´t represent a natural assemblage of the artefact universe of the communities? Why that process stopped at a certain stage and another ditch was open just a couple meters way? Why the ditch was softly waved? Why there are no evidence (on the contrary) of palisades or banks associated to it? Why are there human remains inside the ditch? Why is the ditch section profoundly asymmetric? Why...

In fact, before answer, and instead of assume, we must ask.

Costa, Cláudia (in print), "Problemática do enchimento dos Fossos 3 e 4 (Sector I) dos Perdigões (Reguengos de Monsaraz) com base na análise estratigráfica dos restos faunísticos", III Jornadas do Quaternário. Evolução Paleoambiental e Povoamento no Quaternário do Ocidente Peninsular, Universidade do Minho, Braga.

Valera, António Carlos (2008), “O recinto calcolítico dos Perdigões: fossos e fossas do Sector I.”, Apontamentos de Arqueologia e Património, 3, Lisboa, NIA-ERA, p.19-27.

Valera, A. C. & Silva, A. M. (2011), “Datações de radiocarbono para os Perdigões (1): contextos com restos humanos nos Sectores I e Q”, Apontamentos de Arqueologia e Património, 7, Lisboa, NIA-ERA, p.7-14.

Monday, May 30, 2011

0017 - Walls, where have they came from?

Three or four decades ago, the origin of walled enclosures was a “heat issue” in Portugal. The battle was between two enclosed positions and a traditional "3rd way": the ones that see these architectures as a result of direct diffusion; the ones that see them as an independent local achievement, resulting of local social developments; those in the middle, that talked about local dynamics using external ideas.

Rarely, though, the debate was supported on detailed analyses of the architectures. And some details clearly seem to indicate that, responding to a general and shared European idea (just like the ditched enclosures), there is a strong link to pre-existing knowledge. This can be easily argued to the entrances of Castro de Santiago and Fraga da Pena, in the Ribeira da Muxagata, Fornos de Algodres, Central Portugal.

Castro de Santiago system of entrance.

Both entrances correspond to a short corridor that cuts through the wall and structured by vertical monoliths in each side, leaning against the stone rows of the wall. At Castro de Santiago, the two walls make a bigger corridor between them, and the South wall of the corridor also presents a revetment of vertical monoliths. These architectonic solutions, as I suggested elsewhere (Valera, 2007), seems to be directly derived from megalithic architectonic engineering, since they are very similar to solutions, in concept and layout, adopted in previous passage graves.

Fraga da Pena entrance to inner enclosure.

But the debate is, in fact, a false one, since is basically a problem of scale and of whole / part relationship. At a large scale, at an European level, there is a general trend in Europe. That trend explains the Megalithism, the circular ditched enclosures, the building of stone walls, the sharing of certain technologies, as extended phenomena. It expresses itself through local and regional specific solutions that justify both the observed similarities and particularities. But we shouldn´t regard the whole as the adding of these particular ways. On the contrary, what we regard as part should be understood as a unique, a specific, layout of the whole. Ditched or walled enclosures anywhere should be comprehended in a wider European context, not as a part of that general trend, but as a particular and local rooted expression of it. This overcomes the traditional dichotomy, and allows us to address similarity and difference in an integrated way.

Sunday, May 29, 2011

0016 - Castro de Santiago walled enclosure

Double wall of inside enclosure.

Door of the outside enclosure.

Location: Fornos de Algodres municipality, Guarda district, Beira Alta, Central Portugal)
Chronology: Chalcolithic
Bibliographic references: Valera, 1997; 2007.

Excavated between 1988 and 1996, Castro de Santiago is a walled enclosure dated from Chalcolithic (first quarter of the 3rd millennium BC, by radiocarbon). Distant just 8 Kms from Fraga da Pena, and in the same valley, the site also uses a large granitic tor existent in a prominent hilltop to form two enclosures.

The inner one uses the top rocks that naturally form a “U” shape open to South. The enclosure is established by a double wall with a bastion structure built in the open side of the rock sequence. The two walls structure an entrance in “S” shape and to phases of occupation were detected inside, with huts, fire places and cobble structures.

The outside enclosures is defined by two parallel walls, one at East and the other at West, uniting rock formation at south of the inner enclosure. There is no evidence of structures and areas of sedimentation are rare and small, since the ground is basically constituted by the granitic bedrock.

The site was interpreted as a walled settlement that played a decisive role in the emergence and consolidation of a local identity during the first half of the millennia, process that was declining (through integration in a wider regional system of social relations) by the time Fraga da Pena appeared (Last quarter of the millennia).

Friday, May 27, 2011

0015 - Modular architectures ?

Has been recently suggested (Diaz-del-Rio, 2008) that some structures of Iberian chalcolithic walled enclosures may have a construction organized by modules. It is argued that the main walls (and not just re-buildings or re-enforcements) might have been built in sequences in time and not in short and continuous periods (building at once; building phase). Each module would be a specific project of a specific part of the community and related to the capacity of work and resources mobilization present at each time. The final building would be an aggregation of segmented projects, expressing the social organization of the community itself. As Iberian examples that suggest this sort of modular building Los Millares (south Spain) and Castanheiro do Vento (north Portugal) were presented .

(in Diáz-del-Rio, 2008, adapted)

In fact, this kind of situation has been also observed in ditched enclosures. In Germany, at Herxheim, the final image of a ditch seems to be the result of a sequence of elongated and overlapping pits. The same was reported to the Portuguese enclosure of Salgada, where the ditch was built in sections (see here).

In recent papers on sinuous ditches (Valera, in print) and on the Xancra’s geophysics (Valera & Becker, 2011), I analysed the image of Xancra and question if the same situation is not present, since similar modules (to the ones proposed to Castanehiro do Vento and Los Millares walls) are apparently suggested by the image.

(in Valera & Becker, 2011)

Naturally, this is not just a matter of building strategies. It has strong implications in the theoretical models we generate to these communities. If huge architectonic structures are built in smaller segments through time, requiring less labour mobilization and control, less logistics, they became accessible to smaller segmentary communities of parental bases, that don´t have a developed and strong social hierarchy. If so, we must carefully question how large constructions are, in fact, built and assume that heavy architecture can no longer be use uncritically as undisputed evidence of a highly social and political complexity.

On the other hand, it draws attention to the problem that many constructions are a result of a long process of construction and use, and that there is not an evident gap in time between the “building phase” and the “using phase”: architectures as living processes of construction.

DIÁZ-DEL-RIO, Pedro (2008), “El context social de las agregaciones de población durante el Calcolítico Peninsular”, ERA Arqueologia, 8, Lisboa, Era-Arqueologia / Colibri, p.128-137.
ORSCHIEDT, Jörg e HAIDLE, Miriam Noël (2006), “The LBK enclosure of Herxheim. Theatre of war or ritual centre? References from osteoarchaeological investigations”, Journal of Conflict Archaeology, 2, p.153-167.
VALERA, A.C. e BECKER, H. (2011), “Cosmologia e recintos de fossos da Pré-História Recente: resultados da prospecção geofísica em Xancra (Cuba, Beja)”, Apontamentos de Arqueologia e Património, 7, Lisboa, NIA-ERA Arqueologia, p.23-32.
VALERA, António Carlos (in print), “Fossos sinuosos na Pré-História Recente do Sul de Portugal: ensaio de análise crítica”, Actas do V Encontro de Arqueologia do SW Peninsular.

Thursday, May 26, 2011

0014 - Monte de Cortes 1 ditched enclosure

Location: Serpa municipality, Beja district, Alentejo, South Portugal)
Chronology: Neolithic (?) Chalcolithic (?)
Bibliographic references: Valera et al., in print.

Monte de Cortes 1 is a small ditched enclosure that was surveyed by Era Arqueologia S.A. in the context of rescue archaeology developed in Brinches section (Serpa, Beja) of the water supply project of Edia. The water tube trench cut the enclosure in the middle and two sections of the ditch were excavated. Almost in the middle of the enclosure, a menhir was implanted and another one was recorded nearby at the surface. Some pits, previous to the menhir, were excavated, but no other contexts were found inside the enclosure (along the trench excavated).

According to the evidences, the ditch seems to be of oval or elliptical plan and of short dimensions. The in situ menhir is not at the centre, but slightly to west. The sediments inside the ditched provide few archaeological material, basically some lithics that don´t allow precise chronological determination. Therefore, sediment sampling was done by the Portuguese Nuclear Technological Institute to effect B-OSL dating.

The enclosure of Monte de Cortes 1 is surrounded by pit structures filled with sediments but without archaeological materials. 200m East, in Monte de Cortes 2, several pits were detected and excavated (those with materials suggesting Chalcolithic chronologies) and an hypogeum with human remains dated from the 3rd millennium BC was also excavated.

The site seems to be one and only but, because of the nature of the project (a linear one) and of the police of rescue archaeology (excavation strictly in the affected area), we don´t have the real notion of the spatial connections. We are, then, left to an educated guess: that we are in presence of a complex site, with several specific areas and architectures that we aren´t able to really understand with the available data.

Located in a top hill, with an open view over the local landscape, Monte de Cortes (1 and 2) seems to be an important site in the organization of local landscape, maintaining visual contact with the enclosure and necropolis area of Outeiro Alto 2. Geophysics is programmed, now in the context of research, trying to get an image that allows improvement on interpretation.

Wednesday, May 25, 2011

0013 - Enclosures: centers of convergence

As I was saying, our knowledge of the enclosure phenomenon in South Portugal is changing quickly. But this development is still basically unknown abroad, especially outside the Iberian Peninsula. In fact, we can say that Spain is in the same boat, if we consider the map presented above.

It is a map from the times when Perdigões was discovered. It shows that the enclosure phenomenon is of European scale, but the Iberian Peninsula is almost a desert. Well, at the time (1997), and in Portugal, lots of other walled enclosures were already known. So de map was quite outdated.

But as the numbers of enclosures (and archaeological work on the matter) were growing, especially regarding ditched enclosures, we kept seeing the same European map with a desert Iberia published again and again.

What does this signify? Basically, it represents the low level of internationalization of the Portuguese Archaeology of Recent Prehistory, despite its internal developments over the last 25 years.

In a way, we seem to be enclosed. Not in a way of some Neolithic enclosures, that were meant to aggregate, but in a very insular manner. Fortunately, things have been changing in the last years and Portugal is definitely on the path of joining the “prehistoric European community”. And enclosures are an issue that can contribute to this journey, renewing presently, not without irony, one of their main functions in the process of bringing people together.

The European maps will be progressively updated. In fact, maps like the one above don’t just represent distributions of archaeological sites. They represent much more. They talk about the past but also a lot about the present.

Tuesday, May 24, 2011

0012 - A new landscape

(South Portugal ditched enclosures from 1997 to 2011 - Valera & Becker, in print)

A truly revolution has been in course in the last few years in South Portugal regarding the ditched enclosures. The map on the left shows the situation in 1997, when Perdigões was first excavated after its discovery in the previous year. The map on the right shows the situation today: the number has been almost multiplied by five.

Most of the discoveries have occurred in the context of rescue archaeology, but some were the result of research projects. At the moment, and up to my knowledge, there are three long term research projects on ditched enclosures in the region: the one of Alcalar, developed by administration, and the ones of Perdigões and Archaeoastronomic Fundamentals of Ditched Enclosures Architectures developed by NIA-ERA (with other associated institutions).

There are, though, several academic works being prepared on ditched enclosures in the sequence of rescue archaeological excavation. That is the case, for example, of the large enclosure complex of Porto Torrão. Others, like Outeiro Alto 2 and Cortes, were integrated in wider research projects financed by Portuguese Science and Technology Foundation.

In fact, the last 14 years have seen a substantial change in the “archaeological landscapes” of South Portugal and, consequently, there is a whole new Prehistory to be written. There is a lot of work being done in this issue at the moment, with different theoretical approaches, so a significant development of knowledge is expected in the following years.

Sunday, May 22, 2011

0011 - Outeiro Alto 2 ditched enclosure

Location: Serpa municipality, Beja district, Alentejo, South Portugal)
Chronology: Chalcolithic
Bibliographic references: Valera & Filipe,2010; Valera, in print.

It is an enclosure defined by a single ditch, presenting a design similar to those of Santa Vitória and Xancra: a wavy ditch, forming a sequence of well standardized semi-circular lobes, with an entrance orientated apparently to winter solstice.

It was identified in the context of the water distribution net of Alqueva dam. The ditch was surveyed in two areas by ERA Arqueologia S.A., and the archaeological material point to a Chalcolithic chronology.

The enclosure is at the East end of a small hill, while at the West extremity there is a possible wood henge surrounded by three Late Neolithic hypogea, and in the middle, to South West, a necropolis of pits and anthropomorphic hypogea from Bronze Age. Even in the area of the enclosure, some of the pits excavated revealed Late Neolithic contexts.

So, the enclosure is located in a hill that was developed through time as a space of social aggregation and of sacred and symbolic social practices, where the earlier was a condition for attraction and spatial organization of the later.

An example of a significant “place building” during 1,5 thousand years, showing how deeply rotted can be a sense of place and how meaning can be accumulated through time, generating the social memory of a place and landscape.

Saturday, May 21, 2011

0010 - Moreiros 2 ditched (and palisade) enclosures

Location: Arronches municipality, Évora district, Alentejo, South Portugal)
Chronology: Late Neolithic / Chalcolithic (?)
Bibliographic references: Boaventura, 2007; Becker, Valera & Boaventura, in print; Valera, in print.

Moreiros 2 was identified by Rui Boaventura in a gravel quarry. In the quarry profiles, two ditches were identified and a small ditched enclosure was assumed. Contacting Rui, I had his agreement (and field cooperation) to incorporate the site in the NIA-ERA project (financed by Gulbenkian) on cosmological foundation of enclosures designs and geophysical prospection was done (the team was composed by Helmut Becker leading the geophysics, me, Rui and Nelson Cabaço).

Once again, surprise was expecting us. The site is much bigger and complex that the initial observations suggested. The enclosures go, at list, up to nine (in a provisional counting). The area enclosed is much bigger and some lines of enclosures assume configurations (adapting to the topography) that are quite rare (not to say absolutely new) in the region. Entrances are various in number and configuration. Palisades are, definitively, present in the definition of some of the enclosures.

But, at the surface of the site, almost no material was found. And this is another important result of Moreiros prospection: we have to be very carefully about deductions supported on surface findings. How many enclosures are enclosing “open sites” defined by surface findings in Alentejo?

Surprised by the size, we weren´t able to finish the geophysical survey. We plan to finish it next month, if no further surprises appear (that would be quite welcome, if I may add).

Wednesday, May 18, 2011

0009 - Leceia walled enclosure

Location: (Oeiras municipality, Lisboa district, Estremadura, Central Portugal)
Chronology: Late Neolithic to Late Chalcolithic
Bibliographic references: Cardoso, 1989, 1994, 1997; Soares & Cardoso, 1995.

Leceia is a well known walled enclosure, located near Lisbon, in a Tagus tributary (Barcarena stream). The site stands in the limit of a cliff and, after an open occupation during Late Neolithic (2nd half of the 4th millennium BC), a set of three walls with bastions were built in first quarter of the 3rd millennium. The walls are roughly semicircular and concentric, defining enclosures that use the cliff also as a limit. In a sense, it is the same logical use of topography that we find in the French contemporary enceintes an éperon or in some British proto historic enclosures. In Portugal, the incorporation of that specific topographical pre condition in the design of the enclosures is rare (maybe Columbeira presents the same situation in the north of Lisbon peninsula). More frequent is the use of prominent rock formations, to which walls are added forming the enclosures, as we can see at Fraga da Pena, Castro de Santiago and Castelejo in the hinterland of central Portugal, or in Penedo Lexim, in the Lisbon Peninsula.

At Leceia, after a period of functioning of the walls, it seems that they ruined and occupations continued over those ruins, till a bell beaker phase. The site has a long series of radiocarbon dates.

Interpreted as a fortified settlement of agro pastoralist communities, Leceia is one of the two Portuguese walled enclosures that present an inside funerary context with human remains (the other is Castelo Velho, in the north). In Leceia’s case, the context was interpreted as a dump.

This presence of human remains is, in fact, one of the interesting, and probably meaningful, contextual differences between walled enclosures and the large ditched enclosures, that present an inescapable direct relation to funerary practices and architectures.

Tuesday, May 17, 2011

0008 - Santa Vitória ditched enclosure

Image of the inside enclosure of Santa Vitória, published in Valera & Filipe, 2010, courtesy of Miguel Lago.

Location: (Campo Maior municipality, Portalegre district, Alentejo, South Portugal)
Chronology: Chalcolithic
Bibliographic references: Dias, 1996.

Santa Vitória was the first ditched enclosure identified and partially excavated in Portugal, during the eighties of the XX century. Naturally, according to the dominant paradigm of the time, it was seen as a settlement, a small fortified village, with an earth bank associated to a ditch. The strange configuration of the ditch was seen as a previous design of what would became to be known as the bastion walls (I recently developed a critique on the matter, still in print).

Reconstitution of Santa Vitória by Ippar.

No attention was given to the fact that there was no evidence of bank erosion inside the ditches. The fact that there were structures and clear deposition assemblages inside the ditches were not questioned, since the idea of settlement was also not to be question. Like Rabelais couldn’t be an atheist in the XVII century, this kind of sites couldn´t be anything else but fortified domestic settlements.

Well, nowadays “the times, they are changing”. In the context of winder and strong evidence from other Portuguese enclosures and different theoretical approach, Santa Vitoria can be reviewed. If there was an inside bank, as the reconstitution image suggests, where is the bank earth (supposedly geological material)? Not in the ditch, filled by deposits with a great number of archaeological material, stones and structures. If there was a bank, how could some pits be where they are (in the place of the presumed bank)? The design, we know now, is not unique and seems to respond to a pattern observed in other sites that strongly suggest that there is a cosmological foundation to this design (such as Xancra or Outeiro Alto 2), that have little to do with defence strategy. The apparently summer solstice orientation of the door of the inside enclosure is now being explored in the context of the NIA’s project ”Ditched Enclosures Plans and Neolithic Cosmologies: a landscape, archaeoastronomic and geophysical approach”.

Unfortunately, the publication of excavation results is minimum, which makes it harder to go into deeper discussion, namely about the depositions inside the ditches, since there is news of very well preserve contexts.

Santa Vitória, though, still has a lot of informative potential to the actual debate going on in Iberia about the social role of this kind of sites.

0007 - Human remains in ditches

Human remains in dicth 4 of Perdigões enclosure (I’m not actually refering to the persons in the image :), but to the humam bones off a hand foud in that area of the ditch)

The large enclosures of Southwest Iberia (such as Perdigões, Porto Torrão, Alcalar, Valencina de la Concepción, San Blás or Pijotilla) developed necropolis in peripheral or internal areas, with dolmens, tholoi type monuments, hypogea or pits. But another circumstance is currently and repeatedly reported: the presence of human remains in some of their Chalcolithic ditches. All of the referred present evidences of this practice, with the exception of Alcalar (until now).

Traditionally, the presence of scattered human bones, bodies or parts of bodies was interpreted as discarded rubbish. This is the way the situations in Pijotilla, Valencina or Porto Torrão were interpreted. Recently, in the publication of the first contexts documented at Perdigões (Valera & Godinho, 2010), I argued that this is an European practice and discussed some patterns that indicate intention and meaning, suggesting that this is just another practice of body manipulation and funerary management of the dead, probably articulated with other practices and other scenarios, and that at least some enclosures assumed an important role regarding those practices.

The idea of megalithism, as the main funerary expression of those communities, needs urgent revision. And some enclosures play an important role in that revision, since their traditionally assumed dichotomy settlement/graveyard is starting to be in serious crises.

But even more interesting (at least for me) is the fact that this revision will lead us to inquiries on cognition, world views and notions of the body (and of the concept of unit).

Monday, May 16, 2011

0006 - Perdigões complex of enclosures

Location: (Reguengos de Monsaraz municipality, Évora district, Alentejo, South)
Chronology: Late Neolithic to Late Chalcolithic
Bibliographic references: see here.

The site was identified in the eighties of the XX century, but only in 1996 was recognized in all its extension and architectonic complexity. This happened after a deep plough for planting a vineyard. Now, we know the site has an area around 20ha, and 3/4 is inside de Perdigões farm, a Esporão property. Today, a significant part of this context is an archaeological reserve and has been object of continuous research since 1997, coordinated by NIA-ERA Arqueologia S.A. and participated by several institutions and researchers.

Since 1996 taht we have an aerial photograph that shows several ditched enclosures. But the geophysical prospection undertook in 2009 and 2010 (by Málaga University, whith the coloboration of NIA-ERA and implemented by Helmut Becker) represented a major advance in the knowledge of the site.

(Image publish in Márquez Romero, et al. in print; Valera et. al in print)

The archaeological complex is composed by a sequence of ditches, roughly concentric. The ditches that have been already excavated present different sizes and depths. The central one dates from Late Neolithic, the middle wavy ones from the first half /middle 3rd millennium, and the outside one was still partially open when bell beaker arrived at the site (probably in middle / 2nd half of the 3rd millennium. The site seems to have lived for about 1500 years (condensed in that geophysical image) .

In the east side, the outside ditch defines a semi circular area where a necropolis of collective tombs is located. Two of those tombs were fully excavated and revelled secondary depositions of human remains and a great variety of votive artefacts. The tombs are partially excavated in the bedrock and present different compartments: a circular chamber, a small corridor and an atrium. The chamber and the atrium are coated with clay sediments and schist flagstones, while the corridor was built with small monoliths of diorite. We don’t have information about the roofs.
Although absolute dating is not yet available, the architecture and the material culture point to a Chalcolithic chronology from the first half of the 3rd millennium BC, with a probable reutilisation of Tomb 2 during the late 3rd millennium BC.

But funerary procedures were not restricted to the necropolis. In the inside enclosures, a pits area has been identified and some of the pits present human funerary primary depositions, dated from the transition from 4th to 3rd millennium. In the neighbouring wavy ditches (ditch 3 and 4) human remains were found in the filling deposits and in the central area a pit was filled with remains of human cremations dated from middle 3rd millennium. Funerary practices are, then, quite diversified and complex and seem to be present wherever we dig in the enclosure, as happen in several other European enclosures.

The amount of archaeological material and faunal remains is huge and diverse, revealing a strong interaction with other regional peninsular areas. Apart from local materials, we should highlight the presence of idols made of limestone and ivory, bell beaker pottery, copper and gold artefacts. Analysis showed that the ivory is from African provenance.

The location of Perdigões enclosure has a clear connection to cosmology. Topographically speaking, the enclosure is in an amphitheatre open to East, to the Álamo valley and its megalithic territory, with Monsaraz hill marking the horizon. The necropolis is located precisely in the eastside of the enclosure and next to it, in that same side, there was a cromlech. The doors in that side define the East quadrant, one in each side of the necropolis, and are orientated to both solstices. To North, South and West, visibility is restricted by the topographical limits of the site define when the outside double ditch were built. All architectonic organization suggests planning, intentionality and cosmological bonds.

The site has an interpretative centre in the medieval tower of Esporão farm, near Reguengos de Monsaraz and is now object of one of the most important and innovative research projects of Recent Prehistory Portuguese archaeology. An extensive list of bibliography is available (see above).

0005 - Door designs in ditched enclosures

The ditched enclosures present a significant variety of entrances, from simples ones (corresponding to a simple interruption of the ditch) to more complex ones, that can correlate ditches with wood structures.

In the wavy ditches, the extremity of the ditch can be turning inside (like Santa Vitória (7) or Xancra (2)) or outside (as in Outeiro Alto 2 (8)), depending if it was used the inside or outside curvature to make the interruption of the ditch.

Sometimes, though, the interruption is lateral in the curvature, as in Moreiros (4 and 6). In this way the entrance is not open in a straight line, but implies an also sinuous path to walk through.
This same conditioning can also be obtain by adding a semicircular small ditch or palisade in front of the entrance, like some of the doors at Perdigões (1) or Xancra (3). At Perdigões, this kind of entrance is also monumentalized by two large negative structures, defining a second, but interrupted, semicircular ditch.

These different, but at the same time quite alike, ways of designing the doors of the enclosures have some similar parallels in Europe, showing there are shared ideas relating the building of enclosures, although we can observe regional particularities.

Sunday, May 15, 2011

0004 - Fraga da Pena walled enclosures

Location: (Fornos de Algodres municipality, Guarda district, Beira Alta, Central Portugal)
Chronology: Late Chalcolithic / Early Bronze Age
Bibliographic references: Valera, 1997; 2000; 2007.

The sites corresponds to a spectacular granitic tor that rises, rather strikingly and to a considerable height (750 m of altitude), near the summit of the right slope of Muxagata stream (a tributary of Mondego River). It has a magnificent view over the valley and it is a remarkable land mark.
Two small enclosures were built attached to the tor, using stone walls of 3 meters wide. Traces of human occupation were detected outside, in the top of the slope.
The site has been systematically excavated, revealing the absence of domestic occupation inside. On the contrary, the exceptional assemblage of finds (bell beakers, anthropomorphic figurine, personal ornaments, rock painting), and the rarity of other daily artefacts (such as lithic material or loom weights), suggest that the site had no residential function. Its topography, lower than the top of the slope, clearly make it defensively inefficient. In fact, it looks more like a stage.

Due to its location, Fraga da Pena would have played a significant role in the organization of local landscape over several successive historical periods (as it still does). Its occupation reflects a strategy that sought to exploit both the symbolic and communication potential of the tor. But the wall enclosures shouldn’t be regarded simply as an appending of a structure to a natural rock, but rather as a unified building, where both artificial and natural features were combined and interdependent in generating a place that serve as a stage for certain specific social practices.
Those social practices might be related to a narrow passage in the middle of the tor, connecting the interior of the first enclosure with the other side of the tor, to a natural balcony over a steep scarp. This passage is naturally (?) aligned with East – West axis, so when the sun rises behind the other slope of the valley, light comes through the passages, hitting part of the first enclosure that is in the tor’s shadow. A clear expression of a traditional Neolithic ideological use of landscape and natural elements.

It is a magnificent exemplar of the architecture of the period, combining in meaningful building natural and artificial elements, used to communicate and organize the landscape in the context of social identity fabrics.
Is part of a local archaeological route and its archaeological materials are exhibit in a local museum.

0003 - Forca ditched enclosure

Location: (Maia municipality, Porto district, Douro Litoral, North Portugal)
Chronology: Middle / Late Chalcolithic
Bibliographic references: Valera & Rebuge, 2008.

The Forca site was the first ditched enclosure identified and surveyed in North Portugal and still the only one publicly known in the region, which turns it into a singular case in the Northwest Peninsula archaeological context.

It was surveyed in the context of rescue archaeology and several negative structures were identified and briefly diagnosed: ditches with different orientations, sizes and plans; long and narrow trenches and a large number of sub circular pits. Some of these structures intersected each other, revealing different construction moments, and some evidence of ditched re-cutting were recorded.

One of the ditches (ditch 1) was surveyed in two different locations and revealed different sizes. In order to obtain absolute chronologies for the base of the filling deposits of this structure two samples were collected and dated by B-OSL. One of the samples dated the first filling up of the ditch to the regional middle/late Copper Age (second half of the 3rd millennium).

Unfortunately, the limits and configuration of the enclosures aren’t known, which is a strong limitation to interpretation. Other archaeological work has been done after this first intervention, but still waiting for publication.

0002 - Monte do Olival 1 ditched enclosure

Location: (Ferreira do Alentejo municipality, Beja district, Alentejo, South Portugal)
Chronology: Chalcolithic (Based on surface materials)
Bibliographic references: Umpublished (in print).

Just like I did with Xancra, this enclosure was detected in Google Earth by Manuela de Deus (Igespar).

It is a site with, at least, four enclosures and an entrance is visible, orientated to NE. The site will be integrated in the same project as Xancra and be submitted to geophysical prospection, hopefully next moths. It is very promising.
Topographically, is very similar to Xancra, being located in the middle of a slope orientated to NE.

0001 - Xancra Ditched Enclosure

Location: (Cuba municipality, Beja district, Alentejo, South Portugal)
Chronology: Chalcolithic (Based on surface materials)
Bibliographic references: Valera & Becker, 2011.

I start with the amazing site of Xancra. It was discovered in Google Earth and submitted to geophysical prospecting in the context of the research project ”Ditched Enclosures Plans and Neolithic Cosmologies: a landscape, archaeoastronomic and geophysical approach”, financed by the Portuguese Calouste Gulbenkian Foudation.

Its three ring enclosures have entrances aligned and orientated to Winter solstice, revealing the cosmological foundation of the design of the set of enclosures. This idea is reinforced by topographical location, since the site is in the middle of a slope (eastern orientated) and not at the top.

The number of semicircular elements that compose the ditches suggest that architecture incorporates a moon calendar, since their number is quite coincident with moon phases, days and months.