Classification of wear traces identified on the curved knives
The fact that many curved knives were identified in the materials from the site in Ludowice allowed a detailed comparative analysis of wear traces visible on the knives. This allowed significant divergences in their characteristics to be recorded and could serve as a basis for a more precise functional classification of this type of tools.
It is assumed that a feature of products of this functional type is the presence of different types of polish on their working edges. These are connected to each other and occur in repeatable patterns. In general, it is believed that on most tools, two types of such patterns are encountered. On non-contact surfaces of the knives, there is a bright polish of a flat topography and rough texture (type A), and/or similar to the polish observed on the tools used for working antler, which is of a domed topography and smooth texture (type B). In turn, on contact surfaces, a linear polish is recorded, which is glossy and of a flat topography (type C) or ‘hide’ domed polish of type D. Both are accompanied by slanted linear traces in the form of black striations (Juel Jensen 1994; van Gijn 2010; Osipowicz 2010). Among the identified tools, the most common are specimens with polish of the A–C and B–D patterns. Products with these sort of traces were relatively numerous also in the materials from the analysed sites. As a result of the conducted use-wear analyses, however, curved knives were identified with systems of polish that were substantially different from the adopted ‘standards’. For this reason, an attempt was made here to re-classify them, as a result of which, eight main types of these tools were distinguished (compare Table 1). Some of the identified types of polish have already been mentioned by Juel Jensen (1994) and by other researchers.
The working edges of all distinguished types of curved knives bear usually the same type of use retouch (wide/irregular, one-step, built with the single scars with feather terminations). For this reason, it is not discussed in this work.
Curved knives qualified to this type bear on the ventral faces bright, linear polish usually with a marginal (sometimes medium) degree of intrusion, a domed topography that becomes flat (slightly pitted) near the cutting edge with a quite rough texture. The polish is accompanied by single, perpendicular linear traces (Fig. 3a).
Polish observed on the dorsal faces is legible as a thin line along the edge, with a degree of intrusion reaching medium extend. It is glossy and has a flat/fluted (in some distance from the cutting edge domed) topography and smooth texture (Fig. 3b). The cutting edge is only slightly rounded or not rounded at all.
In the flint collections analysed here, six tools of this type were identified. One of them was discovered in a collection from Sąsieczno, five at the site in Ludowice.
On the ventral faces of the curved knives included in this type occurs a bright polish with a domed topography (flat one only on the cutting edge) and diagonal orientation. The most characteristic here is its very rough texture and the presence of numerous oblique linear traces in the form of black and filled in striations (Fig. 3c). The polish is abrasive and smoothly changes to a surface not covered by wear traces.
On the dorsal faces of the tools of this type, there is glossy, linear polish readable as a thin line along the edge. It has a flat/fluted (slightly pitted) topography and smooth texture. Linear traces are basically absent. The polished surface is quite abruptly cut off from the non-polished one (Fig. 3d). The cutting edge of the tools is only slightly rounded.
Five curved knives included in this category come from the site in Ludowice and one from site 18 in Lubicz.
Two artefacts of this type were discovered in the collection from Ludowice, one at the site in Sąsieczno and one in Paliwodziźna, all of which bear on the ventral faces polish with a characteristic (in general outline) similar to the curved knives of type 2. Their topography, however, is clearly more cratered and therefore similar to the one typical for hide processing (Fig. 3e).
Also, the characteristic of polish observed on the dorsal faces of these artefacts is definitely different from the one typical for tools described above. It is bright, only in some points (at the cutting edge) glossy, has an invasive degree of intrusion and smoothly changes to a non-polished surface. Its topography is domed, only near the cutting edge of it is flat and slightly pitted, and the texture is smooth (Fig. 3f).
It is difficult at this stage in the research to rule out that these are type 2 curved knives, with working edges used for a short time or in a slightly different way, which is why it was decided to label them as sub-type 2a.
Polish legible on the ventral faces of the curved knives of type 3 is visible as a thin line along the edge; however, it can also have an invasive degree of intrusion. It is glossy and has a flat topography, which at a distance from the edge becomes increasingly domed. Its texture is slightly rough (in some points completely smooth). The polish is linear and has diagonal orientation. It is accompanied by single, similarly oriented linear traces (black and filled in striations—Fig. 3g).
Polish characteristic to the dorsal faces of the tools of this type is legible also as a thin line along the edge and can have an invasive degree of intrusion. Very poorly visible, however, is its linearity. The topography is domed and quite pitted, and the texture is smooth. There are no linear traces (Fig. 3h).
The tools of this type were identified mainly from a collection from Ludowice (11 artefacts). One comes from a site in Paliwodzizna.
Similar to the type 2 and 2a specimens, two curved knives were found in the collection from the Ludowice site, which bear wear traces in some aspects similar to those described in the case of type 3 tools, however, different enough that there may be a reason for creating an independent classification category in the future. A tool of this kind was also probably discovered in the collection from Sąsieczno; however, the traces of use discovered on it are too underdeveloped to be confirmed with a high probability.
Polish observed on the ventral faces of these tools is very similar to that described above, but its texture is completely smooth and the polish itself is more ‘metallic’. Additionally, its topography is very flat, in the general profile quite similar to the abrasion typical for the curved knives of type 4 that are described below. The cutting edge of the tools is clearly ‘melted’ and rounded (Fig. 3i).
On the dorsal faces of the specimens of this type polish was observed with a smooth texture, a marginal degree of intrusion and legible as a thin line along the edge. In contrast to the situation recorded in the case of type 3 knives, it is quite clearly cut off from the not-polished surface, its topography is flat (domed in some distance from cutting edge), ‘melted’, and the profile is slightly linear (Fig. 3j).
On the ventral faces of the curved knives classified as a type 4 can be observed a glossy polish/abrasion with a flat topography, smooth or slightly rough texture and diagonal orientation. It is legible as a thin line along the edge and its degree of intrusion is not higher than medium. In contrast to the situation observed on the type 3 tools, the polish is essentially limited to the area in the immediate vicinity of the cutting edge and rapidly cut off from the unpolished surface (Fig. 3k). It is always accompanied with linear traces in a form of diagonal filled in striations. On the cutting edge itself, there are also single scratches in the form of black striations. Sometimes, they are more numerous and visible also on the side surfaces of the working edge, what makes the texture of polish rougher.
On the dorsal faces of the tools can be observed a bright/glossy polish with an even invasive degree of intrusion. It has a flat/fluted (quite pitted) topography, in some (quite large) distance from the cutting edge passing into a domed one. It is linear (oriented diagonal) and has a smooth texture (in some points, slightly rough). The polish quite clearly separates from the unpolished surface, although the transition between them is gradual. There are no linear traces (Fig. 3l).
The tools of this type were identified only in the collection from Ludowice (eight specimens).
This type is represented by two tools. One was found in the collection from the site in Ludowice; the second was on the site in Paliwodzizna. The polish observed on the ventral faces of these tools is legible as a thin line along the edge and has a degree of intrusion from medium to invasive. It is bright (in some points, slightly glossy) and has a domed topography and smooth texture. The polish is slightly linear (oriented diagonal). There are no linear traces (Fig. 4a).
On the dorsal faces of the tools was observed polish with similar characteristic. However, it has a slightly smaller degree of intrusion (maximum medium), and, what is more important, a pitted (near the cutting edge flat/pitted) topography and with a rough texture. Also, here, there are no linear traces (Fig. 4b).
Curved knives of type 6 are represented only by one tool that was discovered in the collection from Ludowice. The polish observed on its ventral side is glossy and has a marginal degree of intrusion (it covers only the cutting edge itself). It has a flat topography and a slightly rough texture with linear traces in a form of delicate scratches (black striations), oriented perpendicularly to the orientation of the tool (Fig. 4c).
The polish discovered on the dorsal face of the specimen has a medium degree of intrusion. It is glossy and has a flat/pitted (slightly fluted) topography and a generally smooth texture. The polish is linear (oriented diagonal), there are no linear traces (Fig. 4d) and the working edge is rounded.
The polish recorded on the ventral faces of the curved knives of type 7 is different from those described for the types analysed so far. It is matt and has an invasive degree of intrusion, a cratered topography and a rough texture (reminiscent of work on dry hide). It is legible as a band along the edge, which is very rounded. The polish is accompanied with linear traces in a form of diagonal black striations (Fig. 4e).
On the dorsal faces of the tools of this type was observed bright/glossy and slightly linear polish with a medium degree of intrusion and a smooth texture, legible as a thin line along the edge. Its topography is domed, sometimes slightly fluted, but near the cutting edge is flat. Linear traces (diagonal filled in striations) occur only sporadically (Fig. 4f).
The polish observed on curved knives classified as type 7 corresponds to the one classified in the literature as type 23 (van Gijn 1989, 2010). All three tools of this kind were discovered in the materials from the site in Ludowice.
Use-wear traces identified on the ventral faces of the specimens in this group are similar to those of type 7. The polish visible here is therefore matt, readable as a thin line or band along the edge and has an even invasive degree of intrusion. Its topography is cratered and the texture is rough. It is accompanied by linear traces in a form of slightly diagonal black striations. The working edge is rounded (Fig. 4g).
The polish visible on the dorsal faces of this type of specimen, however, has slightly different characteristics and appears less developed. It is bright and has the character of a thin, sometimes disappearing line along the edge. It covers mostly the higher parts of the microrelief, its topography is domed (in some points passing into the flat) and its texture is slightly rough. In a sense, it is a kind of abrasion of the upper parts of the microrelief. There are no linear traces (Fig. 4h). In addition, atypical spread polish was observed. All four curved knives bearing such traces appeared in the collection from the site in Ludowice.
It cannot be ruled out that specimens of types 7 and 7a were used for similar activities. Perhaps the usage traces recorded on them occurred even during the same type of activity but illustrate its various stages. The nature of usable traces observed on the dorsal faces of these tools, however, seems to be sufficiently different to treat them independently, at least for now.
A distinct category (type 8) outside the created classification should involve a tool obtained from site 13 in Lubicz (Fig. 2: 19). It is an example of a product referred to by H. Juel Jensen (1994) as microdenticulate, since its blade was made by means of a fine intentional retouch that gave it a micro-serrated form. It has been suggested that these tools were applied to combing plant fibres for textile production (Juel Jensen 1994). This suggestion can be supported by wear traces visible on the described specimen, whose characteristics and arrangement correspond in general to those visible on the curved knives classified to type 2 (Fig. 4i). However, these cover the entire surface of the intentional retouch negatives without ‘overlapping’ in an invasive manner with the side edges of the working edge, suggesting that the tool was applied to the processed raw material close to the right angle. This tool is hence clearly different to other specimens of the discussed functional type, since movements performed with it most probably were similar to scraping and not whittling, as in the case of typical curved knives.
Experimental study results
The programme of experimental studies was based on the findings of studies performed on site 6 in Ludowice, which could be a place specialising in siliceous plant processing. Thus, the location was probably not a coincidence but determined by easy access to the raw material. In this case, such plants should be found in the palynological profile.
In line with the results of the conducted studies of this type, at the time when the Mesolithic settlements in Ludowice were functioning, the prevailing herbaceous plants were sedges (Cyperaceae) and grasses (Poaceae), which are local species of the peat bog situated here. Ferns (Filicales monolete) and marsh ferns (Thelypteris palustris) are represented and a relatively high and stable curve is created by the eagle fern (Pteridium aquilinum). Wetland plant species are increasingly represented, among which nearly continuous curves are formed by the bogbean (Menyanthes trifoliata), water lilies (Nymphaea), the bur-reed (Sparganium) and the common cattail (Typha latifolia). Of spore plants with a high silica content, the common horsetail (Equisetum arvense) can also be identified in small numbers (Noryśkiewicz reportFootnote 2; Osipowicz 2017).
In the experimental programme, the following plant species were taken into account: two sedge species common in Poland, namely the greater tussock-sedge (Carex paniculata) and the lesser pond-sedge (Carex acutiformis), the common cattail (Typha latifolia), the marsh fern (Thelypteris palustris), the eagle fern (Pteridium aquilinum) and the horsetail (Equisetum). Other species identified in the palynological profile proved currently inaccessible or (as in the case of the European white water lily) conservation-dependent.
All plants taken into account in the experimental programme were identified in archaeological contexts and are also used by humans in the present day. The sedge is used for making wattles, ropes and mats. They also serve as an excellent bedding material (Podbielkowski and Sudnik-Wójcikowska 2003). Young common cattail plants are used as fodder. Its shoots, roots and above-ground parts of stems are sometimes eaten as a vegetable, while leaves and flower stems are used for making mats and wattles. The fibre obtained from leaves is turned into ropes. Also, this plant is considered to have therapeutic properties (Podbielkowski and Sudnik-Wójcikowska 2003). These, as well as cosmetic properties, are also ascribed to the common horsetail (Podbielkowski and Sudnik-Wójcikowska 2003) which is collected from May until September and used for treating, among others, neoplasms and eye diseases. It is also believed to strengthen blood vessels and to have anti-haemorrhagic and diuretic properties (Górnicka 2003). The eagle fern, whose remains have been excavated in Mesolithic sites, also has a very wide use (Makohonienko 2000). In the Mesolithic period, its most probable use was, among others, as food (Göranson 1986), the edible parts including starch-rich rhizomes and also young leaves. In present times, its shoots are also used for making fabrics and ropes that are particularly valued for their resistance to moisture (Makohonienko 2000). It also has therapeutic properties. Although the marsh fern has a less broad application, some species of this fern have been used to fight worms and ringworm (Stichmann-Marny and Kretzschmar 1994; Podbielkowski and Sudnik-Wójcikowska 2003). In the Mesolithic, they could have also been used as mattresses (Grøn 1995).
In the course of the study, various parts of plants were subjected to processing. The experiments were more than 60 and up to 90-min long. For the purpose of the experiment, 10 blades made of Baltic erratic flint of natural straight or slightly concave working edges (analogous to historical products) were used. The blades were knapped from the same nodule of the raw material, and all tools were hafted. The experiments were conducted in a slightly different manner depending on the species of the processed plant (Fig. 5). Experiments which involved splitting the fibres of the greater tussock-sedge and the lesser pond-sedge, as well as splitting leaves of the common cattail, entailed the plants being drawn between the tool blade and the thumb at nearly right angles. The splitting of the stems of the common cattail and the common horsetail was performed by whittling with the angle of contact consistently maintained at 30°. The experimental processing of rhizomes of the common cattail entailed cleaning them from impurities and basal shoots, and then splitting (whittling) into narrow strips. In the course of processing roots of the common horsetail and the eagle fern, two activities were performed. First, they were cleaned of impurities, and then the external wooden parts were gently whittled to reach the soft inner ‘flesh’. Processing stems of the eagle fern consisted of removing leaves and then cleaning and splitting (whittling) the stems to obtain fibres. In the course of the experiments on the marsh fern, stems and above-ground parts of stems were processed. The work comprised two activities. The first removed leaves by drawing the stems between the tool blade and the thumb. The second attempted to split the fibres in the stems is by means of whittling to uncover the ‘flesh’ of the above-ground parts of stems.
As a result of the conducted experiments, highly diverse wear traces were produced (Figs. 6, 7); the characteristics of which are presented in Table 2.