4.0 Results

4.1. Raw materials - Mineralogical analysis

Petrographic analysis of the raw materials indicated that there are two main types of workable materials in the vicinity of the site:

4.1.1 Weathering soils, overlying the marly sequences (Figure 4)

Macroscopically, these are characterised by a light red, clayish sediment containing many millimetre-sized fragments of a white biomicrite. The material, the so-called terra rossa, is composed mainly of calcite (about 34 wt.% CO2), subordinate quartz, plagioclase and minerals of the illite-muscovite and of the montmorillonite-chlorite series. The average inclusion content is 25%, mostly of chalk fragments from 500 µm to 4mm in size. Shells of planktonic Foraminifera like Globigerinae and Bolivinae occur in high amounts. Additionally, there are fragments of chert, grains of biotite, muscovite, hornblende, pyroxene, plagioclase and quartz, as well as euhedral calcite crystals, about 60 µm in size. Fish and plant remains, glauconite and heavy minerals like zircon, rutile and titanite are also observed in lower amounts.

4.1.2 Soft marly chalk (Figure 5)

This soft, workable, clayish material is characterised by an ochre-grey colour and high amounts of organic remains, like roots. It is composed mainly of calcite (about 39 wt. % CO2) and small amounts of quartz and minerals of the illite-muscovite series. The inclusion content of about 10-20% by volume is characterized mostly by fully preserved shells, as well as fragments of planktonic Foraminifera from 50 to 300 µm in size. The shells over 100 µm in size are normally filled either with glauconite or calcite. The diversification of the fossil types is very small. Besides the bioclasts, subangular grains of quartz, euhedral calcite crystals, grains of green hornblende, pyroxene, biotite, muscovite, glauconite, as well as very few fragments of basalt and biomicrite, can also be observed. Heavy minerals, especially titaniferous ones, are observed in trace amounts.

4.2. Artefacts - Mineralogical analysis

Petrographical analysis of the figurines identified three different fabric types, independently of their shape and colour.

4.2.1 Figurines of calcareous clay (Figures 6 and 7)

This is the most common fabric type among the samples, represented by 26 figurines. Its matrix is composed mainly of calcite and quartz, followed by feldspars like albite and microcline, as well as clay minerals of the illite-muscovite series. The weathering soils of marly sequences described in 4.1.1 are the most likely raw material source (Figure 4).

The material contains on average 20-30% by volume of temper composed of medium sorted, subangular to angular mineral grains between 40-100 µm, rock fragments between 200-800 µm and bioclasts between 200-500 µm in size. Among the minerals, quartz, feldspar and calcite grains are the most common. Next in abundance are micas (muscovite as well as biotite), hornblende, pyroxene, titaniferous heavy minerals (rutile, anatase, ilmenite and titanite) and zircon. Glauconite, apatite and collophane occur as trace minerals and some barite concentrations could be recognised under the SEM. The grains of hornblende are either brownish or show browny rims.

The bioclasts are composed mainly of shells of planktonic Foraminifera and the rock fragments are characterised by chalk and fossiliferous limestone. Chert and basalt fragments are practically absent. Remains of charcoal are often observed.

The pores are characterised by being closed, often irregular in shape but sometimes straw-shaped. The fossil shells show in many cases an incipient decomposition, showing that the temperature may have reached about 700°C (see 5.0 Discussion). No glassy phases could be identified in the matrix of any sample.

4.2.2 Figurines of soft marly chalk (Figures 8 and 9)

This is the second most common material type, represented by four samples. Its fine-grained matrix is composed of a calcareous material (about 90% carbonates) with iron oxide impregnations, so this material can be easily confused with Neolithic lime plasters. Mineralogically it is composed mainly of calcite and small amounts of quartz. Additionally, plagioclase and a clay mineral, probably illite, are present. These figurines were most likely produced using the local soft marly chalk described in 4.1.2 (Figure 5). The temper content varies from 5 to 15% by volume and is composed mainly of subangular to rounded grains of calcite, quartz and plagioclase, up to 100 µm in size. Secondary minerals include muscovite, biotite, zircon and titaniferous heavy minerals (rutile, anatase, titanite and ilmenite), while apatite, pyroxene, brownish hornblende, glauconite, chlorite and collophane occur as trace minerals.

Apart from the mineral grains, bioclasts up to 500 µm in size are very common and composed mostly of well preserved planktonic Foraminifera shells that sometimes show incipient decomposition, indicating that the temperature may have been between 600° and 650°C (see 5.0 Discussion). The very few rock fragments are of biomicrite, chert and basalt.

4.2.3 Figurines of carved limestone (Figures 10 and 11)

This type of material was observed in only two of the 32 samples and corresponds petrographically to a dense marly chalk. It shows a fine-grained calcitic matrix with recrystallised microveins of calcite and iron oxide impregnations.

The rock matrix contains low amounts of a clay mineral, most likely illite, and very few micrograins of quartz. It can be easily differentiated from the previous figurine type due to its lower amount of inclusions and micas. The microfauna is characterised by fragments of different kinds of fossils like Foraminifera and Echinodermata, in addition to well-preserved shells of Serpoliden and Robertinidae. The rock is petrographically very similar to those found in the vicinity, to the north of the site.

4.3 Artefacts - Chemical analysis

The main chemical composition, identified using XRF analysis of 20 samples, is plotted in a triangular diagram (Figure 12). It shows that objects coming from the same archaeological level and with the same colour are not necessarily of the same chemical and mineralogical compositions, the colour differences being determined mainly by the firing process and not by the raw material used. It also shows that the petrographical classification corresponds to the chemical one, the three identified figurine groups being represented by the three circles on the graph. Figure 13 represents the result of INAA analysis of 25 samples of figurines made of calcareous clay. It shows the variation of the trace element concentrations normalised to scandium and to the clay standard Tony-HD4, represented on a logarithmic scale. The trace element pattern of the figurines of calcareous clay (grey area) are quite similar, indicating that they all have been made of the same raw material independently of their temper content and quality. Furthermore, there is also a chemical similarity between these figurines and the weathering soils of the region (black area), suggesting these as the most likely source, in accordance with the petrographic observations.


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Last updated: Tue Oct 24 2000