Obtención de parámetros de envejecimiento

Clay is an extremely versatile material. It is plastic and malleable, and its proper-ties can be altered by adding water or particles such as graphite, grog or straw dust. Clay becomes solid through drying, and it is turned into ceramics through firing. The plasticity of the clay means that it can easily be shaped and moulded with fingers and simple tools. In principle, every child can play with clay and form simple objects, although, of course, there are degrees of craftsmanship in use that can be read from the finished product (cf. Sofaer and Budden 2012). It is the most democratic material, as it is easily obtainable and probably did not have much value. It could be worked anywhere and everywhere and finished and fired in a household context, with pyrotechnology available at most homes where peo-ple cook. Whereas pottery for everyday use was probably produced in household contexts, ceramics found in funerary contexts show marked differences in quality and in terms of object biography. Some had already been used for domestic tasks, whereas other pieces were especially produced for the grave or altered specifically for use as funerary vessels.

Clay was used as building material and to make vessels used for serving, eat-ing and drinkeat-ing and prepareat-ing and storeat-ing food, as well as other objects such as spindle whorls, loom weights and zoomorphic and anthropomorphic figurines.

Making large vessels that have uniform wall thicknesses and do not break when drying and firing is difficult. They clearly had a certain value as a finished prod-uct, as they were frequently repaired when they cracked: at Statzendorf, Austria (Rebay 2006: 50), vessels were repaired by drilling two holes on either side of the crack and tying the wall together with string; other methods of fixing broken ves-sels include using lead and iron clasps.

Clay can easily be decorated using just hands, fingernails and simple tools such as sticks, pieces of straw or jewellery at hand. Pieces of clay can be added and connected to the main body, but clay can also be incised or impressed. Adding a human image on a drying clay vessel before firing is a task that is very easily done; in fact, it is so easy that one has to wonder why the highly decorated early Iron Age vessels do not show figurative decorations more often than they do. The level of detail in the image depends largely on the technique of decoration. Details can be expressed clearly with incisions, and the resolution drops markedly when using point incisions or impressions.

When using clay to make figurines (Rebay-Salisbury 2014), the affordances of the material favour certain body shapes, such as a round, large and plump body core, whereas elongated and thin parts of the body such as the neck, arms and legs are more difficult to shape as they are prone to breaking; they are therefore often shorter than they would be in the natural body. The properties of the clay also affect the way faces appear. Eyes and noses are normally made by impressing and squeezing a tiny bit of clay out of the main body that constitutes the face; for that reason, faces often appear slightly bird-like.

6.3.3 Bronze

Bronze technology was well established by the early Iron Age (cf. Kienlin 2013);

access to bronze as a material and to the knowledge required to work it, however, was most likely not ubiquitous. It remained the primary material for art and orna-ments, although iron began to be exploited and worked in the central European early Iron Age around 800 ^bc. Iron is not as easy to work into fine, detailed objects such as jewellery and human figurines, and was first primarily used for weapons, tools and horse gear. It is further prone to corrosion, so even if it was worked to an ornament, it may not have been preserved. Bronze is an alloy of copper and about 10 per cent tin (with the percentage of tin varying considerably in prehistory) and other metal inclusions or additives such as iron or nickel. Copper was mined at a considerable scale in central Europe at sites such as Mitterberg and Eisenerz in Austria (O’Brien 2013: Fig. 24.1), but tin had to be traded in. The Bronze Age trade networks spanning the European continent still seemed to be in place at the beginning of the early Iron Age. The role of recycling, however, cannot be under-estimated. Even if no obvious traces of reworking can be detected, scrap metal most likely formed the basis of the majority of early Iron Age bronze working.

Casting bronze requires reaching a temperature of about 950° C and a few simple tools such as crucibles, tongs and moulds; it is unsurprising that such simple metal workshops are much more difficult to trace archaeologically than smelting sites.

Human images in bronze were made using four basic techniques. First, lost-wax casting was employed for figurines, pendants, attachments and the like. Second, casting in open moulds was an option. Third, sheet bronze objects were decorated with punched images or in repoussé and chasing, and fourth, figures were cut out of sheet bronze. It is the combination of the affordances of the materials and techniques used to work them that influences the shape the human image can take.

Lost-wax casting requires making a model of the desired product in wax, which shares many properties with clay: it is extremely malleable, but more viscous and less prone to breaking. The fact that wax models have to be stabilised in clay moulds makes long and slim shapes possible and has the added benefit of not having to use very much metal, which may be quite precious and costly. Figu-rines and pendants thus have slimmer and thinner body shapes (Rebay-Salisbury 2014). Lost-wax casting produces exactly one copy of a bronze item, whereas open moulds or composite moulds can be re-used. Open mould casting results in relief figures, with a flat reverse, which is not normally worked further. The human

The image and the object 133 image therefore appears two- rather than truly three-dimensional and has a chosen perspective, that is, shows the person from the front, right, left or a combination of these. All cast bronze objects are usually refined after casting, when they can be filed and polished to smooth any casting marks, or punched and incised to add fur-ther details. Fine features of faces and clothing are frequently indicated in this way.

Sheet bronze production and decoration almost certainly required the knowl-edge and skill of an experienced craftsperson. Bronze was hammered from ingots to produce sheets of about 0.2 to 1 mm thickness, which was then cut into the required shapes and assembled into objects like situlae and cists by folding and riveting the sheets together. Some decorations may have been added before the final assembling, but others could be added later. The primary techniques to deco-rate sheet bronze, and indeed to make human images on sheet bronze, are inci-sions, stamps and punches, and repoussé and chasing. Most often, a combination of these techniques is used. Incisions produce the images with the most detail, but the incisions can be so fine that they are hard to see, particularly from farther away. Images composed of punched points are also an option. The resolution of the human images is low, and they can be difficult to read, particularly when they merge into patterns such as on the cists found in the Kröll-Schmiedkogel at Klein-klein, Austria (e.g., Ziste XIII, Schmid 1933: pl. 1c). Anthropomorphic punches producing repetitive images of very small size are primarily used in southwestern Germany and beyond to decorate sheet bronze belts. The repoussé and chasing technique, in which the bronze sheet is ornamented from the reverse side to cre-ate a design in low relief, is widespread in Slovenia and northern Italy. Whereas repoussé creates the raised design on the front by hammering from the back, chas-ing refines the design on the front by sinkchas-ing the metal. The plasticity of the sheet metal means that there is no loss of material – the bronze is stretched and the surface remains continuous. The produced relief effect is usually not particularly strong in Situla Art, but the technique can highlight particular facial and body fea-tures. At Magdalenska gora, Slovenia, for example, working cheeks in repoussé creates a chubby-faced appearance of the depicted persons (e.g., Lucke and Frey 1962: pl. 41, Tecco Hvala, Dular and Kocuvan 2004: app. 3).

Sheet bronze objects and their fragments can be recycled by cutting out shapes and figures. Many of the plaques dedicated in sanctuaries were in fact produced this way. Scrap metal certainly had a lower value than ‘fresh’ sheet bronze and was relatively easy to cut. Details could be added by punching and incising.

A two-dimensional outline of a person is often the result, with a few thin and long breaking points: necks and details of arms and legs are therefore frequently omit-ted. Recycling sheet bronze in this way can probably be done by everyone.

6.3.4 Lead

Casting lead is a technology rarely applied except for the site of Frög, Austria (Plate 15, Tomedi 2002), where thousands of small figures, primarily riders, were produced. Both lost-wax casting and open mould casting are possible; casting in perishable and temporary moulds made of sand, wood or charcoal is a further

possibility. Although there is some evidence of subsequent treatment such as forg-ing, cutting and bendforg-ing, most figures were put in the graves as raw casts, regard-less of casting mistakes or fuzzy edges. Almost certainly the figurines were made for funerary use.

Lead as a material is relatively easy to work, as it can be melted at very low heat (327° C); the light of a candle is in fact sufficient. The material remains soft after casting and can be bent easily. Legs and arms are rarely preserved at full length, but most of the time, they appear elongated. Whereas legs appear straight and par-allel, the arms are bent into various gestures: some hang parallel to the body, some are crossed in front of the chest, some carry various objects or are raised. This indeed seems to be one of the crucial advantages of using lead as a material: the same basic forms can be cast over and over and varied, as well as being adjusted by bending the soft metal carefully into the desired shapes.

Lead is widely obtainable in central Europe, easy to smelt and work and did not seem to have been of particular value, as it was, for instance, used to repair ceramic vessels. It is likely, however, that lead formed the economic basis of the early Iron Age community of Frög, and the use of this material was a symbolic component in the local funerary rites.